Atomix - User contributions [en]

Netcdf dimensions (shear probes)

2024-05-24T20:09:11Z

KikiSchulz: /* Netcdf dimensions (shear probes) */

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension !! Level || Description
|-
| TIME || L1 || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || L1 || length of the record from slow data channels (if different from fast)
|-
| N_SHEAR_SENSORS || L1 || number of shear channels (shear sensors)
|-
| N_***_SENSORS <math>^b</math> || L1 || number of *** channel (sensors)
|-
| TIME || L2 || length of the record from turbulence (fast) data channels
|-
| N_SHEAR_SENSORS || L2 || number of shear channels (shear sensors)
|-
| N_***_SENSORS <math>^b</math> || L2 || number of *** channel (sensors)
|-
| TIME_SPECTRA || L3 || length of the record of average times of spectral segments
|-
| N_WAVENUMBER || L3 || length of the wavenumber array
|-
| N_***_SENSORS <math>^b</math> || L3 || number of *** channel (sensors)
|-
| N_SH_ACC_SPEC <math>^c</math> || L3 || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC <math>^d</math> || L3 || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^e</math> || L3 || dimension for 1 data point (for the entire analysis)
|-
| TIME_SPECTRA || L4 || length of the record of average times of spectral segments
|-
| N_SHEAR_SENSORS || L4 || number of shear channels (shear sensors)
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors.
<br>
<math>^b</math> Example dimension names would be: N_VIB_SENSORS for vibration (piezo-acceleration) sensors, N_ACC_SENSORS for
vibration acceleration sensors.
<br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>

<math>^e</math> Dimension for variables of the size 1x1 for variables such as N_FFT_SEGMENTS and DOF. <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf dimensions (shear probes)

2024-05-24T20:05:10Z

KikiSchulz: /* Netcdf dimensions (shear probes) */

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension !! Level || Description
|-
| TIME || L1 || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || L1 || length of the record from slow data channels (if different from fast)
|-
| N_SHEAR_SENSORS || L1 || number of shear channels (shear sensors)
|-
| N_***_SENSORS <math>^b</math> || L1 || number of *** channel (sensors)
|-
|-
| TIME || L2 || length of the record from turbulence (fast) data channels
|-
| N_SHEAR_SENSORS || L2 || number of shear channels (shear sensors)
|-
| TIME_SPECTRA || L3 || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SH_ACC_SPEC <math>^c</math> || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC <math>^d</math> || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^e</math> || dimension for 1 data point (for the entire analysis)
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and eventually _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br><br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors <br>
N_GRADT_SENSORS for thermistors <br>
N_GRADC_SENSORS for microconductivity sensors <br>
<br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>

<math>^e</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Level 3 data (shear probes)

2024-05-24T19:56:38Z

KikiSchulz: /* Dimensions */

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^a</math> || dimension for 1 data point (for the entire analysis)
|}
</div>

<math>^a</math> Dimension for variables of the size 1x1 for variables such as N_FFT_SEGMENTS and DOF. <br>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! dimension
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || R || shear_probe_spectrum || s-2 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS
|-
| KCYC || R || cyclic_wavenumber || cpm || TIME_SPECTRA, N_WAVENUMBER
|-
| SH_SPEC_CLEAN || R || shear_probe_spectrum_clean || s-2 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS
|-
| N_FFT_SEGMENTS || R || number_of_fft_segments || - || N_GLOBAL_VALUES
|-
| N_VIB_SENSORS || R || number_of_vibration_sensors_used_for_cleaning_spectra || - || N_GLOBAL_VALUES
|-
| SPEC_STD || R || standard_deviation_uncertainty_of_shear_spectrum || - || N_GLOBAL_VALUES
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || O || acceleration_sensor_spectrum || m2 s-4 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS
|-
| VIB_SPEC || O || vibration_sensor_spectrum || - || TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS
|-
| SH_VIB_SPEC || O || shear_and_vibration_cross-spectral_matrix || - || TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC
|-
| SH_ACC_SPEC || O || shear_and_acceleration_cross-spectral_matrix || - || TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC
|-
| DOF || O || degrees_of_freedom_of_spectrum || - || N_GLOBAL_VALUES
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Level 2 data (shear probes)

2024-05-24T19:55:02Z

KikiSchulz: /* Dimensions */

Level 2 data, that is saved in the NetCDF group "L2_cleaned", are the full resolution, cleaned and despiked parameters from level 1. The initial data set is subdivided in [[Section|sections]] and labeled accordingly in the parameter SECTION_NUMBER with integers. Level 2 data is ready for estimating spectra. In addition to cleaned and despiked level 1 data channels, level 2 data comprises the additional parameter summarized in the table below.

It is important that the platform speed with respect to water, as used in the dissipation estimates, is included in this level. Also note that the shear probe time series (and optionally acceleration and vibration) must be cleaned and filtered as needed at this level, and will not be altered further when estimating dissipation rates.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension !! Description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^a</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Example dimension names would be: N_VIB_SENSORS for vibration (piezo-acceleration) sensors, N_ACC_SENSORS for
vibration acceleration sensors.
</div>

=Variables=

<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME
|-
| VIB || HR || platform_vibration || m s-2, or -<math>^d</math> || TIME, N_VIB_SENSORS
|-
| ACC || O || platform_acceleration || m s-2, or -<math>^d</math> || TIME , N_ACC_SENSORS
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: Acceleration and vibration sensors are sometimes not calibrated and their records are used as raw values.
</div>

[[Category: Shear probes]]

------
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 1 data (shear probes)| Level 1 data]]<br>
go to next: [[Level 3 data (shear probes)| Level 3 data]].

Level 1 data (shear probes)

2024-05-24T19:53:48Z

KikiSchulz: /* Dimensions */

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension !! Description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different from fast)
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Unit !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || HR|| platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| VIB || HR || platform_vibration || - || TIME, N_VIB_SENSORS
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure|| dbar || TIME
|-
| TEMP || HR || [sea]<math>^c</math>_water_temperature || degree_Celsius || TIME, N_T_SENSORS
|-
| ACC || O || platform_acceleration || m s-2 || TIME, N_ACC_SENSORS
|-
| CNDC || O || [sea]<math>^c</math>_water_electrical_conductivity || S m-1 || TIME_CTD, N_C_SENSORS
|-
| GRADT || O || derivative_of_[sea]<math>^c</math>_water_temperature_wrt_<math>^{*d}</math>|| degree_Celcius m-1 || TIME, N_GRADT_SENSORS
|-
| GRADC || O || derivative_of_[sea]<math>^c</math>_water_conductivity_wrt_<math>^{*d}</math> || - || TIME, N_GRADC_SENSORS
|-
| PITCH || O || platform_pitch_angle || degree || TIME
|-
| ROLL || O || platform_roll_angle || degree || TIME
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Level 2 data (shear probes)

2024-05-24T19:53:27Z

KikiSchulz: /* Dimensions */

Level 2 data, that is saved in the NetCDF group "L2_cleaned", are the full resolution, cleaned and despiked parameters from level 1. The initial data set is subdivided in [[Section|sections]] and labeled accordingly in the parameter SECTION_NUMBER with integers. Level 2 data is ready for estimating spectra. In addition to cleaned and despiked level 1 data channels, level 2 data comprises the additional parameter summarized in the table below.

It is important that the platform speed with respect to water, as used in the dissipation estimates, is included in this level. Also note that the shear probe time series (and optionally acceleration and vibration) must be cleaned and filtered as needed at this level, and will not be altered further when estimating dissipation rates.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension !! Description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
|N_SHEAR_SENSORS ||number of shear channel (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> At this level platform speed must be provided. We require that this is given at the shear probe time (not TIME_SLOW or TIME_CTD. Please interpolate if needed.
<br>
<math>^b</math> Please use these examples for related sensors, e.g.:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors
</div>

=Variables=

<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME
|-
| VIB || HR || platform_vibration || m s-2, or -<math>^d</math> || TIME, N_VIB_SENSORS
|-
| ACC || O || platform_acceleration || m s-2, or -<math>^d</math> || TIME , N_ACC_SENSORS
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: Acceleration and vibration sensors are sometimes not calibrated and their records are used as raw values.
</div>

[[Category: Shear probes]]

------
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 1 data (shear probes)| Level 1 data]]<br>
go to next: [[Level 3 data (shear probes)| Level 3 data]].

Level 1 data (shear probes)

2024-05-24T19:53:08Z

KikiSchulz: /* Dimensions */

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different from fast)
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Unit !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || HR|| platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| VIB || HR || platform_vibration || - || TIME, N_VIB_SENSORS
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure|| dbar || TIME
|-
| TEMP || HR || [sea]<math>^c</math>_water_temperature || degree_Celsius || TIME, N_T_SENSORS
|-
| ACC || O || platform_acceleration || m s-2 || TIME, N_ACC_SENSORS
|-
| CNDC || O || [sea]<math>^c</math>_water_electrical_conductivity || S m-1 || TIME_CTD, N_C_SENSORS
|-
| GRADT || O || derivative_of_[sea]<math>^c</math>_water_temperature_wrt_<math>^{*d}</math>|| degree_Celcius m-1 || TIME, N_GRADT_SENSORS
|-
| GRADC || O || derivative_of_[sea]<math>^c</math>_water_conductivity_wrt_<math>^{*d}</math> || - || TIME, N_GRADC_SENSORS
|-
| PITCH || O || platform_pitch_angle || degree || TIME
|-
| ROLL || O || platform_roll_angle || degree || TIME
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Level 2 data (shear probes)

2024-05-24T19:52:54Z

KikiSchulz: /* Dimensions */

Level 2 data, that is saved in the NetCDF group "L2_cleaned", are the full resolution, cleaned and despiked parameters from level 1. The initial data set is subdivided in [[Section|sections]] and labeled accordingly in the parameter SECTION_NUMBER with integers. Level 2 data is ready for estimating spectra. In addition to cleaned and despiked level 1 data channels, level 2 data comprises the additional parameter summarized in the table below.

It is important that the platform speed with respect to water, as used in the dissipation estimates, is included in this level. Also note that the shear probe time series (and optionally acceleration and vibration) must be cleaned and filtered as needed at this level, and will not be altered further when estimating dissipation rates.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
|N_SHEAR_SENSORS ||number of shear channel (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> At this level platform speed must be provided. We require that this is given at the shear probe time (not TIME_SLOW or TIME_CTD. Please interpolate if needed.
<br>
<math>^b</math> Please use these examples for related sensors, e.g.:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors
</div>

=Variables=

<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME
|-
| VIB || HR || platform_vibration || m s-2, or -<math>^d</math> || TIME, N_VIB_SENSORS
|-
| ACC || O || platform_acceleration || m s-2, or -<math>^d</math> || TIME , N_ACC_SENSORS
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: Acceleration and vibration sensors are sometimes not calibrated and their records are used as raw values.
</div>

[[Category: Shear probes]]

------
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 1 data (shear probes)| Level 1 data]]<br>
go to next: [[Level 3 data (shear probes)| Level 3 data]].

Netcdf meta data (shear probes)

2024-05-24T19:51:03Z

KikiSchulz: /* Optional Metadata */

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Attibute Name !! Description !! Convention
|-
|title || A comprehensive title for the dataset including the time and location aspect || CF, ACDD
|-
|authors || A list of authors || ATOMIX
|-
|summary || An abstract describing the dataset || ACCD
|-
|comment|| Supplementary technical details about the collecting and processing of the dataset || CF, ACDD
|-
|platform_type || The platform from which the data are collected, e.g., sub-surface mooring, research vessel, sub-surface glider || ACDD
|-
|source || The instrument used for collecting the data. For example, vertical microstructure profiler, VMP2000 SN009 || CF, ACDD
|-
|date_created || The date on which the data were created, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|date_modified || The date on which the data were last modified, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_reference_year || Year for time reference || ATOMIX
|-
|time_coverage_start || Time of the first data point in the dataset, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_coverage_end || Time of thelast data point in the dataset, yyyy-mm-ddTHH:MM:SSZ ||ACDD
|-
|geospatial_lat_min || Southern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lat_max || Northern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lon_min || Western bound of data, decimal degrees, negative for West || ACDD
|-
|geospatial_lon_max || Eastern bound of data, decimal degrees, negative for West || ACDD
|-
| fs_fast || Sampling frequency for fast (turbulence) channels || ATOMIX
|-
| fs_slow <math>^a</math> || Sampling frequency for slow channels (if exists). Alternative names could be, e.g., fs_CTD || ATOMIX
|-
| profiling_direction || Direction along which the section was collected, e.g., horizontal, vertical, or glide || ATOMIX
|-
| fft_length || Length of the Fast Fourier transform segments (in data points; note, fft_lengths_sec in seconds is optional) || ATOMIX
|-
| diss_length || Length of data (in data points) used for each dissipation estimate || ATOMIX
|-
| overlap || Length of overlap (in data points) in diss_length || ATOMIX
|-
| goodman || Flag for the vibration coherent noise removal using the Goodman algorithm. 0=not applied; 1=applied || ATOMIX
|-
| HP_cut || The high-pass filter cutoff frequency in Hz. Can be zero for no filtering. || ATOMIX
|-
| conventions || A comma-separated list of the conventions that are followed by the dataset. e.g., CF-1.6, ACDD-1.3, ATOMIX || CF, ACDD
|-
| history || Provides an audit trail for modifications to the original data; e.g., Version 1 || CF, ACDD
|}
It is highly recommended to duplicate relevant attributes at the corresponding
group level. Attributes not listed in the Climate and Forecast (CF) and the Attribute Convention for Data Discovery (ACDD)
standards are labeled as ATOMIX.
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Attribute Name !! Description !! Convention
|-
| fft_length_sec || Length of the Fast Fourier transform segments in seconds || ATOMIX
|-
| diss_length_sec || Dissipation estimate data length in seconds || ATOMIX
|-
| overlap_sec || Length of overlap (in seconds) in diss_length_sec || ATOMIX
|-
| f_AA || The anti-aliasing frequency in Hz || ATOMIX
|-
| FOM_limit || Figure of merit limit for quality assurance. Typically between 1.15 and 1.4. || ATOMIX
|-
| diss_ratio_limit || The limit to identify anomalously large disagreement between dissipation estimates from probes. The magnitude of the difference of the natural logarithm of two dissipation estimates should be smaller than diss_ratio_limit <math>\times \sigma_{\ln \varepsilon}</math>. Typically, 2.77. || ATOMIX
|-
| despike_shear_fraction_limit || The maximum allowed fraction of data (of each diss_length_sec length) removed by de-spiking. Typically, 0.05. || ATOMIX
|-
| despike_shear_iterations_limit || The maximum number of allowed iterations of de-spiking when producing the L2 shear probe data (one value per section). Typically 8. || ATOMIX
|-
| variance_resolved_limit || The minimum fraction of variance resolved in an estimate by spectral integration. Typically 0.6. || ATOMIX
|-
| f_limit || The upper limit to exclude frequencies from analysis. Typically infinity. || ATOMIX
|-
| fit_2_isr || Dissipation threshold for using the method of fitting in the inertial subrange. Typically <math>10^{−5}</math> W kg<math>^{−1}</math>. || ATOMIX
|-
| spectral_model || The model shear spectrum used in dissipation estimates with the integration method: e.g., Nasmyth, Lueck or Panchev-Kesich || ATOMIX
|-
|area || The region where the data were collected, e.g., Arctic Ocean, Barents Sea || ATOMIX
|-
|geospatial_vertical_min|| Further refinement of the geospatial bounding box. Vertical minimum in m || ACDD
|-
|geospatial_vertical_max|| Further refinement of the geospatial bounding box. Vertical maximum in m || ACDD
|-
|geospatial_vertical_positive|| Direction of positive vertical: down, up || ACDD
|-
|institution || The name of the institution principally responsible for originating this data || CF, ACDD
|-
|principal_investigator || Name of the principal investigator who created the data || ATOMIX
|-
|contact || Name of the contact person || ACDD
|-
|project || The scientific project that produced the data || ACDD
|-
|cruise || The name or number of the research cruise || ATOMIX
|-
|vessel || The name of the research vessel || ATOMIX
|-
|references || A list of related references || CF, ACDD
|-
|keywords || A comma-separated list of keywords and phrases || ACDD
|-
|creator_name || The data creator’s name || ACDD
|-
|creator_email || The data creator’s email || ACDD
|-
|creator_url || The data creator’s URL || ACDD
|-
|acknowledgement|| Acknowledgement of support for the project that produced this data || ACDD
|-
|station_name || The name of the station where data were collected || ATOMIX
|-
|license || Provide the URL to a standard or specific license, e.g, http://creativecommons.org/licenses/by/4.0/, Freely Distributed, or None || ACDD
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Level 1 data (shear probes)

2024-05-24T19:44:26Z

KikiSchulz: /* Variables */

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different from fast)
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Unit !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || HR|| platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| VIB || HR || platform_vibration || - || TIME, N_VIB_SENSORS
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure|| dbar || TIME
|-
| TEMP || HR || [sea]<math>^c</math>_water_temperature || degree_Celsius || TIME, N_T_SENSORS
|-
| ACC || O || platform_acceleration || m s-2 || TIME, N_ACC_SENSORS
|-
| CNDC || O || [sea]<math>^c</math>_water_electrical_conductivity || S m-1 || TIME_CTD, N_C_SENSORS
|-
| GRADT || O || derivative_of_[sea]<math>^c</math>_water_temperature_wrt_<math>^{*d}</math>|| degree_Celcius m-1 || TIME, N_GRADT_SENSORS
|-
| GRADC || O || derivative_of_[sea]<math>^c</math>_water_conductivity_wrt_<math>^{*d}</math> || - || TIME, N_GRADC_SENSORS
|-
| PITCH || O || platform_pitch_angle || degree || TIME
|-
| ROLL || O || platform_roll_angle || degree || TIME
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Netcdf meta data (shear probes)

2024-05-24T19:43:43Z

KikiSchulz: /* Optional Metadata */

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Attibute Name !! Description !! Convention
|-
|title || A comprehensive title for the dataset including the time and location aspect || CF, ACDD
|-
|authors || A list of authors || ATOMIX
|-
|summary || An abstract describing the dataset || ACCD
|-
|comment|| Supplementary technical details about the collecting and processing of the dataset || CF, ACDD
|-
|platform_type || The platform from which the data are collected, e.g., sub-surface mooring, research vessel, sub-surface glider || ACDD
|-
|source || The instrument used for collecting the data. For example, vertical microstructure profiler, VMP2000 SN009 || CF, ACDD
|-
|date_created || The date on which the data were created, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|date_modified || The date on which the data were last modified, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_reference_year || Year for time reference || ATOMIX
|-
|time_coverage_start || Time of the first data point in the dataset, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_coverage_end || Time of thelast data point in the dataset, yyyy-mm-ddTHH:MM:SSZ ||ACDD
|-
|geospatial_lat_min || Southern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lat_max || Northern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lon_min || Western bound of data, decimal degrees, negative for West || ACDD
|-
|geospatial_lon_max || Eastern bound of data, decimal degrees, negative for West || ACDD
|-
| fs_fast || Sampling frequency for fast (turbulence) channels || ATOMIX
|-
| fs_slow <math>^a</math> || Sampling frequency for slow channels (if exists). Alternative names could be, e.g., fs_CTD || ATOMIX
|-
| profiling_direction || Direction along which the section was collected, e.g., horizontal, vertical, or glide || ATOMIX
|-
| fft_length || Length of the Fast Fourier transform segments (in data points; note, fft_lengths_sec in seconds is optional) || ATOMIX
|-
| diss_length || Length of data (in data points) used for each dissipation estimate || ATOMIX
|-
| overlap || Length of overlap (in data points) in diss_length || ATOMIX
|-
| goodman || Flag for the vibration coherent noise removal using the Goodman algorithm. 0=not applied; 1=applied || ATOMIX
|-
| HP_cut || The high-pass filter cutoff frequency in Hz. Can be zero for no filtering. || ATOMIX
|-
| conventions || A comma-separated list of the conventions that are followed by the dataset. e.g., CF-1.6, ACDD-1.3, ATOMIX || CF, ACDD
|-
| history || Provides an audit trail for modifications to the original data; e.g., Version 1 || CF, ACDD
|}
It is highly recommended to duplicate relevant attributes at the corresponding
group level. Attributes not listed in the Climate and Forecast (CF) and the Attribute Convention for Data Discovery (ACDD)
standards are labeled as ATOMIX.
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Attribute Name !! Description !! Convention
|-
| fft_length_sec || Length of the Fast Fourier transform segments in seconds || ATOMIX
|-
| diss_length_sec || Dissipation estimate data length in seconds || ATOMIX
|-
| overlap_sec || Length of overlap (in seconds) in diss_length_sec || ATOMIX
|-
| f_AA || The anti-aliasing frequency in Hz || ATOMIX
|-
| FOM_limit || Figure of merit limit for quality assurance. Typically between 1.15 and 1.4. || ATOMIX
|-
| diss_ratio_limit || The limit to identify anomalously large disagreement between dissipation estimates from probes. The magnitude of the difference of the natural logarithm of two dissipation estimates should be smaller than diss_ratio_limit <math>\times \sigma_{\ln \varepsilon}</math>. Typically, 2.77. || ATOMIX
|-
| despike_shear_fraction_limit || The maximum allowed fraction of data (of each diss_length_sec length) removed by de-spiking. Typically, 0.05. || ATOMIX
|-
| despike_shear_iterations_limit || The maximum number of allowed iterations of de-spiking when producing the L2 shear probe data (one value per section). Typically 8. || ATOMIX
|-
| variance_resolved_limit || The minimum fraction of variance resolved in an estimate by spectral integration. Typically 0.6. || ATOMIX
|-
| f_limit || The upper limit to exclude frequencies from analysis. Typically infinity. || ATOMIX
|-
| fit_2_isr || Dissipation threshold for using the method of fitting in the inertial subrange. Typically <math>10^{−5}</math> W kg<math>^{−1}</math> || ATOMIX
|-
| spectral_model || e.g., Nasmyth, Lueck or Panchev-Kesich
|-
| spectrum_std || statistical uncertainty (standard deviation) of the natural logarithm of spectrum of shear
|-
| num_vibration_goodman || number of vibration or acceleration time series used to clean the shear spectrum
|-
|eps_remove_top_meters || if applicable, upper meters removed from dissipation estimates (e.g., because of ship)
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|-
|license || the URL to a standard or specific license,
e.g, http://creativecommons.org/licenses/by/4.0/, Freely Distributed, or None
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf meta data (shear probes)

2024-05-24T19:39:25Z

KikiSchulz: /* Optional Metadata */

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Attibute Name !! Description !! Convention
|-
|title || A comprehensive title for the dataset including the time and location aspect || CF, ACDD
|-
|authors || A list of authors || ATOMIX
|-
|summary || An abstract describing the dataset || ACCD
|-
|comment|| Supplementary technical details about the collecting and processing of the dataset || CF, ACDD
|-
|platform_type || The platform from which the data are collected, e.g., sub-surface mooring, research vessel, sub-surface glider || ACDD
|-
|source || The instrument used for collecting the data. For example, vertical microstructure profiler, VMP2000 SN009 || CF, ACDD
|-
|date_created || The date on which the data were created, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|date_modified || The date on which the data were last modified, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_reference_year || Year for time reference || ATOMIX
|-
|time_coverage_start || Time of the first data point in the dataset, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_coverage_end || Time of thelast data point in the dataset, yyyy-mm-ddTHH:MM:SSZ ||ACDD
|-
|geospatial_lat_min || Southern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lat_max || Northern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lon_min || Western bound of data, decimal degrees, negative for West || ACDD
|-
|geospatial_lon_max || Eastern bound of data, decimal degrees, negative for West || ACDD
|-
| fs_fast || Sampling frequency for fast (turbulence) channels || ATOMIX
|-
| fs_slow <math>^a</math> || Sampling frequency for slow channels (if exists). Alternative names could be, e.g., fs_CTD || ATOMIX
|-
| profiling_direction || Direction along which the section was collected, e.g., horizontal, vertical, or glide || ATOMIX
|-
| fft_length || Length of the Fast Fourier transform segments (in data points; note, fft_lengths_sec in seconds is optional) || ATOMIX
|-
| diss_length || Length of data (in data points) used for each dissipation estimate || ATOMIX
|-
| overlap || Length of overlap (in data points) in diss_length || ATOMIX
|-
| goodman || Flag for the vibration coherent noise removal using the Goodman algorithm. 0=not applied; 1=applied || ATOMIX
|-
| HP_cut || The high-pass filter cutoff frequency in Hz. Can be zero for no filtering. || ATOMIX
|-
| conventions || A comma-separated list of the conventions that are followed by the dataset. e.g., CF-1.6, ACDD-1.3, ATOMIX || CF, ACDD
|-
| history || Provides an audit trail for modifications to the original data; e.g., Version 1 || CF, ACDD
|}
It is highly recommended to duplicate relevant attributes at the corresponding
group level. Attributes not listed in the Climate and Forecast (CF) and the Attribute Convention for Data Discovery (ACDD)
standards are labeled as ATOMIX.
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Attribute Name !! Description !! Convention
|-
| fft_length_sec || Length of the Fast Fourier transform segments in seconds || ATOMIX
|-
| diss_length_sec || Dissipation estimate data length in seconds || ATOMIX
|-
| overlap_sec || Length of overlap (in seconds) in diss_length_sec || ATOMIX
|-
| f_AA || The anti-aliasing frequency in Hz || ATOMIX
|-
| FOM_limit || Figure of merit limit for quality assurance. Typically between 1.15 and 1.4. || ATOMIX
|-
| diss_ratio_limit || The limit to identify anomalously large disagreement between dissipation estimates from probes. The magnitude of the difference of the natural logarithm of two dissipation estimates should be smaller than diss_ratio_limit <math>\times \sigma_{\ln \varepsilon}</math>. Typically, 2.77
|-
| despike_shear_fraction_limit || non-dimensional, if absent the de-spike fraction QC-flag is not set. Typically, 0.05.
|-
| despike_shear_iterations_limit || non-dimensional, if absent the de-spike iteration passes QC-flag is not set. Typically 8.
|-
| variance_resolved_limit || threshold for the minimum percent of variance resolved in a shear spectrum. Typically 50%.
|-
| spectral_model || e.g., Nasmyth, Lueck or Panchev-Kesich
|-
| spectrum_std || statistical uncertainty (standard deviation) of the natural logarithm of spectrum of shear
|-
| num_vibration_goodman || number of vibration or acceleration time series used to clean the shear spectrum
|-
| f_limit || upper limit to exclude frequencies that have contaminations. Typically infinity.
|-
| fit_2_isr || dissipation threshold to use the method of fitting to the inertial subrange. Typically 10-5 W/kg.
|-
|eps_remove_top_meters || if applicable, upper meters removed from dissipation estimates (e.g., because of ship)
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|-
|license || the URL to a standard or specific license,
e.g, http://creativecommons.org/licenses/by/4.0/, Freely Distributed, or None
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf meta data (shear probes)

2024-05-24T19:33:06Z

KikiSchulz:

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Attibute Name !! Description !! Convention
|-
|title || A comprehensive title for the dataset including the time and location aspect || CF, ACDD
|-
|authors || A list of authors || ATOMIX
|-
|summary || An abstract describing the dataset || ACCD
|-
|comment|| Supplementary technical details about the collecting and processing of the dataset || CF, ACDD
|-
|platform_type || The platform from which the data are collected, e.g., sub-surface mooring, research vessel, sub-surface glider || ACDD
|-
|source || The instrument used for collecting the data. For example, vertical microstructure profiler, VMP2000 SN009 || CF, ACDD
|-
|date_created || The date on which the data were created, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|date_modified || The date on which the data were last modified, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_reference_year || Year for time reference || ATOMIX
|-
|time_coverage_start || Time of the first data point in the dataset, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_coverage_end || Time of thelast data point in the dataset, yyyy-mm-ddTHH:MM:SSZ ||ACDD
|-
|geospatial_lat_min || Southern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lat_max || Northern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lon_min || Western bound of data, decimal degrees, negative for West || ACDD
|-
|geospatial_lon_max || Eastern bound of data, decimal degrees, negative for West || ACDD
|-
| fs_fast || Sampling frequency for fast (turbulence) channels || ATOMIX
|-
| fs_slow <math>^a</math> || Sampling frequency for slow channels (if exists). Alternative names could be, e.g., fs_CTD || ATOMIX
|-
| profiling_direction || Direction along which the section was collected, e.g., horizontal, vertical, or glide || ATOMIX
|-
| fft_length || Length of the Fast Fourier transform segments (in data points; note, fft_lengths_sec in seconds is optional) || ATOMIX
|-
| diss_length || Length of data (in data points) used for each dissipation estimate || ATOMIX
|-
| overlap || Length of overlap (in data points) in diss_length || ATOMIX
|-
| goodman || Flag for the vibration coherent noise removal using the Goodman algorithm. 0=not applied; 1=applied || ATOMIX
|-
| HP_cut || The high-pass filter cutoff frequency in Hz. Can be zero for no filtering. || ATOMIX
|-
| conventions || A comma-separated list of the conventions that are followed by the dataset. e.g., CF-1.6, ACDD-1.3, ATOMIX || CF, ACDD
|-
| history || Provides an audit trail for modifications to the original data; e.g., Version 1 || CF, ACDD
|}
It is highly recommended to duplicate relevant attributes at the corresponding
group level. Attributes not listed in the Climate and Forecast (CF) and the Attribute Convention for Data Discovery (ACDD)
standards are labeled as ATOMIX.
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
| fft_length_sec || seconds
|-
| diss_length_sec || seconds
|-
| overlap_sec || (for diss_length_sec) seconds
|-
| f_AA || Hz, the anti-aliasing frequency.
|-
| FOM_limit || non-dimensional, if absent the FOM QC-flag is not set. Typically, 1.15. It can be as large as 1.4.
|-
| diss_ratio_limit || non-dimensional, if absent the dissipation ration QC-flag is not set. Typically, 2.77.
|-
| despike_shear_fraction_limit || non-dimensional, if absent the de-spike fraction QC-flag is not set. Typically, 0.05.
|-
| despike_shear_iterations_limit || non-dimensional, if absent the de-spike iteration passes QC-flag is not set. Typically 8.
|-
| variance_resolved_limit || threshold for the minimum percent of variance resolved in a shear spectrum. Typically 50%.
|-
| spectral_model || e.g., Nasmyth, Lueck or Panchev-Kesich
|-
| spectrum_std || statistical uncertainty (standard deviation) of the natural logarithm of spectrum of shear
|-
| num_vibration_goodman || number of vibration or acceleration time series used to clean the shear spectrum
|-
| f_limit || upper limit to exclude frequencies that have contaminations. Typically infinity.
|-
| fit_2_isr || dissipation threshold to use the method of fitting to the inertial subrange. Typically 10-5 W/kg.
|-
|eps_remove_top_meters || if applicable, upper meters removed from dissipation estimates (e.g., because of ship)
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|-
|license || the URL to a standard or specific license,
e.g, http://creativecommons.org/licenses/by/4.0/, Freely Distributed, or None
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf meta data (shear probes)

2024-05-24T19:32:44Z

KikiSchulz: /* Required Metadata */

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Attibute Name !! Description !! Convention
|-
|title || A comprehensive title for the dataset including the time and location aspect || CF, ACDD
|-
|authors || A list of authors || ATOMIX
|-
|summary || An abstract describing the dataset || ACCD
|-
|comment|| Supplementary technical details about the collecting and processing of the dataset || CF, ACDD
|-
|platform_type || The platform from which the data are collected, e.g., sub-surface mooring, research vessel, sub-surface glider || ACDD
|-
|source || The instrument used for collecting the data. For example, vertical microstructure profiler, VMP2000 SN009 || CF, ACDD
|-
|date_created || The date on which the data were created, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|date_modified || The date on which the data were last modified, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_reference_year || Year for time reference || ATOMIX
|-
|time_coverage_start || Time of the first data point in the dataset, yyyy-mm-ddTHH:MM:SSZ || ACDD
|-
|time_coverage_end || Time of thelast data point in the dataset, yyyy-mm-ddTHH:MM:SSZ ||ACDD
|-
|geospatial_lat_min || Southern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lat_max || Northern bound of data, decimal degrees, negative for South || ACDD
|-
|geospatial_lon_min || Western bound of data, decimal degrees, negative for West || ACDD
|-
|geospatial_lon_max || Eastern bound of data, decimal degrees, negative for West || ACDD
|-
| fs_fast || Sampling frequency for fast (turbulence) channels || ATOMIX
|-
| fs_slow <math>^a</math> || Sampling frequency for slow channels (if exists). Alternative names could be, e.g., fs_CTD || ATOMIX
|-
| profiling_direction || Direction along which the section was collected, e.g., horizontal, vertical, or glide || ATOMIX
|-
| fft_length || Length of the Fast Fourier transform segments (in data points; note, fft_lengths_sec in seconds is optional) || ATOMIX
|-
| diss_length || Length of data (in data points) used for each dissipation estimate || ATOMIX
|-
| overlap || Length of overlap (in data points) in diss_length || ATOMIX
|-
| goodman || Flag for the vibration coherent noise removal using the Goodman algorithm. 0=not applied; 1=applied || ATOMIX
|-
| HP_cut || The high-pass filter cutoff frequency in Hz. Can be zero for no filtering. || ATOMIX
|-
| conventions || A comma-separated list of the conventions that are followed by the dataset. e.g., CF-1.6, ACDD-1.3, ATOMIX || CF, ACDD
|-
| history || Provides an audit trail for modifications to the original data; e.g., Version 1 | CF, ACDD
|}
It is highly recommended to duplicate relevant attributes at the corresponding
group level. Attributes not listed in the Climate and Forecast (CF) and the Attribute Convention for Data Discovery (ACDD)
standards are labeled as ATOMIX.
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
| fft_length_sec || seconds
|-
| diss_length_sec || seconds
|-
| overlap_sec || (for diss_length_sec) seconds
|-
| f_AA || Hz, the anti-aliasing frequency.
|-
| FOM_limit || non-dimensional, if absent the FOM QC-flag is not set. Typically, 1.15. It can be as large as 1.4.
|-
| diss_ratio_limit || non-dimensional, if absent the dissipation ration QC-flag is not set. Typically, 2.77.
|-
| despike_shear_fraction_limit || non-dimensional, if absent the de-spike fraction QC-flag is not set. Typically, 0.05.
|-
| despike_shear_iterations_limit || non-dimensional, if absent the de-spike iteration passes QC-flag is not set. Typically 8.
|-
| variance_resolved_limit || threshold for the minimum percent of variance resolved in a shear spectrum. Typically 50%.
|-
| spectral_model || e.g., Nasmyth, Lueck or Panchev-Kesich
|-
| spectrum_std || statistical uncertainty (standard deviation) of the natural logarithm of spectrum of shear
|-
| num_vibration_goodman || number of vibration or acceleration time series used to clean the shear spectrum
|-
| f_limit || upper limit to exclude frequencies that have contaminations. Typically infinity.
|-
| fit_2_isr || dissipation threshold to use the method of fitting to the inertial subrange. Typically 10-5 W/kg.
|-
|eps_remove_top_meters || if applicable, upper meters removed from dissipation estimates (e.g., because of ship)
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|-
|license || the URL to a standard or specific license,
e.g, http://creativecommons.org/licenses/by/4.0/, Freely Distributed, or None
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Level 4 data (shear probes)

2024-05-24T19:18:29Z

KikiSchulz:

Level 4 data include the final dissipation estimates as time series, as well as indicators for the quality and accuracy of the estimates and additional derived parameters. It is saved in the NetCDF group "L4_dissipation". Each dissipation estimate in level 4 corresponds to a spectrum in the level 3 data. Consequently, the level 3 and 4 TIME dimensions are the same. Parameter EPSI_FINAL is the final dissipation rate estimate, averaged of the selected estimates (using the [[Quality_control_coding | QC flags]]) at that depth.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|}
</div>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section _of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME_SPECTRA ||
|-
| EPSI || R || specific_turbulent_kinetic_energy_dissipation _in_[sea]<math>^b</math>_water || W kg-1 || TIME_SPECTRA, N_SHEAR_SENSORS
|-
| EPSI_FINAL || R || specific_turbulent_kinetic_energy_dissipation _in_[sea]<math>^c</math>_water || W kg-1 || TIME_SPECTRA
|-
| KMAX || R || maximum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm || TIME_SPECTRA, N_SHEAR_SENSORS
|-
| N_S || R || number_of_spectral_points_used_for_estimating_turbulent_kinetic_energy_dissipation || - || TIME_SPECTRA, N_SHEAR_SENSORS
|-
| EPSI_FLAGS || R || dissipation_qc_flags || - || TIME_SPECTRA, N_SHEAR_SENSORS
|-
| METHOD || R || method_used_for_estimating_ turbulent_kinetic_energy_dissipation || - || TIME_SPECTRA, N_SHEAR_SENSORS
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure || dbar || TIME_SPECTRA
|-
| KVISC || HR || kinematic_viscosity_of_[sea]<math>^c</math>_water || m2 s-1 || TIME_SPECTRA
|-
| FOM || HR || figure_of_merit || - || TIME_SPECTRA, N_SHEAR_SENSORS
|-
| EPSI_STD || HR || expected_standard_deviation_of_the_ logarithm_of_the_dissipation_estimate || - ||TIME_SPECTRA, N_SHEAR_SENSORS
|-
| MAD || O || mean_absolute_deviation || - || TIME_SPECTRA, N_SHEAR_SENSORS
|-
| VAR_RESOLVED || O || variance_resolved || - || TIME_SPECTRA, N_SHEAR_SENSORS
|-
| KMIN || O || minimum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm ||TIME_SPECTRA, N_SHEAR_SENSORS
|-
| DESPIKE_FRACTION_SH || O || fraction_of_shear_data_modified_by_despiking_algorithm || - ||TIME_SPECTRA, N_SHEAR_SENSORS
|-
| DESPIKE_PASS_COUNT_SH || O || number_of_despike_passes_for_shear_probes || - ||TIME_SPECTRA, N_SHEAR_SENSORS
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment

</div>

-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 3 data (shear probes)| Level 3 data]].
[[Category:Shear probes]]

Level 4 data (shear probes)

2024-05-24T19:09:22Z

KikiSchulz:

Level 4 data include the final dissipation estimates as time series, as well as indicators for the quality and accuracy of the estimates and additional derived parameters. It is saved in the NetCDF group "L4_dissipation". Each dissipation estimate in level 4 corresponds to a spectrum in the level 3 data. Consequently, the level 3 and 4 TIME dimensions are the same. Parameter EPSI_FINAL is the final dissipation rate estimate, averaged of the selected estimates (using the [[Quality_control_coding | QC flags]]) at that depth.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|}
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimensions
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^c</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section _of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA ||
|-
| EPSI || specific_turbulent_kinetic_energy_dissipation _in_water || W kg-1 || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_FINAL || specific_turbulent_kinetic_energy_dissipation _in_water || W kg-1 || TIME_SPECTRA
|-
| KMIN || minimum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| KMAX || maximum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| N_S || number_of_spectral_points_used_for_estimating_turbulent_kinetic_energy_dissipation || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_STD || expected_standard_deviation_of_the_ logarithm_of_the_dissipation_estimate || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_FLAGS <math>^a</math> || dissipation_qc_flags || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| METHOD <math>^b</math>|| method_used_for_estimating_ turbulent_kinetic_energy_dissipation || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| KVISC || kinematic_viscosity_of_water || m2 s-1 || TIME_SPECTRA
|-
| FOM || figure_of_merit || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| MAD || mean_absolute_deviation || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| VAR_RESOLVED || variance_resolved || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| DESPIKE_FRACTION_SH || fraction_of_shear_data_modified_by_despiking_algorithm || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| DESPIKE_PASS_COUNT_SH || number_of_despike_passes_for_shear_probes || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment

</div>

-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 3 data (shear probes)| Level 3 data]].
[[Category:Shear probes]]

Level 3 data (shear probes)

2024-05-24T19:05:30Z

KikiSchulz:

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^a</math> || dimension for 1 data point (for the entire analysis)
|}
</div>

<math>^a</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! dimension
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || R || shear_probe_spectrum || s-2 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS
|-
| KCYC || R || cyclic_wavenumber || cpm || TIME_SPECTRA, N_WAVENUMBER
|-
| SH_SPEC_CLEAN || R || shear_probe_spectrum_clean || s-2 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS
|-
| N_FFT_SEGMENTS || R || number_of_fft_segments || - || N_GLOBAL_VALUES
|-
| N_VIB_SENSORS || R || number_of_vibration_sensors_used_for_cleaning_spectra || - || N_GLOBAL_VALUES
|-
| SPEC_STD || R || standard_deviation_uncertainty_of_shear_spectrum || - || N_GLOBAL_VALUES
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || O || acceleration_sensor_spectrum || m2 s-4 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS
|-
| VIB_SPEC || O || vibration_sensor_spectrum || - || TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS
|-
| SH_VIB_SPEC || O || shear_and_vibration_cross-spectral_matrix || - || TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC
|-
| SH_ACC_SPEC || O || shear_and_acceleration_cross-spectral_matrix || - || TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC
|-
| DOF || O || degrees_of_freedom_of_spectrum || - || N_GLOBAL_VALUES
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Level 3 data (shear probes)

2024-05-24T19:04:46Z

KikiSchulz:

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^a</math> || dimension for 1 data point (for the entire analysis)
|}
</div>

<math>^a</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! dimension
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || R || shear_probe_spectrum || s-2 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS
|-
| KCYC || R || cyclic_wavenumber || cpm || TIME_SPECTRA, N_WAVENUMBER
|-
| SH_SPEC_CLEAN || R || shear_probe_spectrum_clean || s-2 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS
|-
| N_FFT_SEGMENTS || R || number_of_fft_segments || - || N_GLOBAL_VALUES
|-
| N_VIB_SENSORS | R || number_of_vibration_sensors_used_for_cleaning_spectra || - || N_GLOBAL_VALUES
|-
| SPEC_STD || R || standard_deviation_uncertainty_of_shear_spectrum || - || N_GLOBAL_VALUES
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || O || acceleration_sensor_spectrum || m2 s-4 cpm-1 || TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS
|-
| VIB_SPEC || O || vibration_sensor_spectrum || - || TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS
|-
| SH_VIB_SPEC || O || shear_and_vibration_cross-spectral_matrix || - || TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC
|-
| SH_ACC_SPEC || O || shear_and_acceleration_cross-spectral_matrix || - || TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC
|-
| DOF || O || degrees_of_freedom_of_spectrum || - || N_GLOBAL_VALUES
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Level 3 data (shear probes)

2024-05-24T18:54:20Z

KikiSchulz:

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^a</math> || dimension for 1 data point (for the entire analysis)
|}
</div>

<math>^a</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^a</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || shear_probe_spectrum || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, N_WAVENUMBER]
|-
| SH_SPEC_CLEAN<math>^b</math>|| shear_probe_spectrum_clean || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| N_FFT_SEGMENTS || number_of_fft_segments || - || N_GLOBAL_VALUES
|-
| N_***_SENSORS<math>^c</math> || number_of_vibration_sensors_or_acceleration_channel_used_for_cleaning_spectra || - || N_GLOBAL_VALUES
|-
| SPEC_STD || standard_deviation_uncertainty_of_shear_spectrum || - || N_GLOBAL_VALUES
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || acceleration_sensor_spectrum || m2 s-4 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS]
|-
| VIB_SPEC || vibration_sensor_spectrum || - || [TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS]
|-
| SH_VIB_SPEC ||shear_and_vibration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC]
|-
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC]
|-
| DOF || degrees_of_freedom_of_spectrum || - || N_GLOBAL_VALUES
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Level 3 data (shear probes)

2024-05-24T18:53:52Z

KikiSchulz: /* Required Variables */

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^a</math> || dimension for 1 data point (for the entire analysis)
|}
</div>

<math>^a</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^a</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || shear_probe_spectrum || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, N_WAVENUMBER]
|-
| SH_SPEC_CLEAN<math>^b</math>|| shear_probe_spectrum_clean || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| N_FFT_SEGMENTS || number_of_fft_segments || - || N_GLOBAL_VALUES
|-
| N_***_SENSORS<math>^c</math> || number_of_vibration_sensors_or_acceleration_channel_used_for_cleaning_spectra || - || N_GLOBAL_VALUES
|-
| SPEC_STD || standard_deviation_uncertainty_of_shear_spectrum || - || N_GLOBAL_VALUES
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
</div>

=Optional Level 3 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || acceleration_sensor_spectrum || m2 s-4 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS]
|-
| VIB_SPEC || vibration_sensor_spectrum || - || [TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS]
|-
| SH_VIB_SPEC ||shear_and_vibration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC]
|-
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC]
|-
| DOF || degrees_of_freedom_of_spectrum || - || N_GLOBAL_VALUES
|}
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Level 1 data (shear probes)

2024-05-24T18:51:48Z

KikiSchulz: /* Variables */

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different from fast)
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Unit !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || HR|| platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| VIB || HR || platform_vibration || - || TIME, N_VIB_SENSORS
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure|| dbar || TIME
|-
| TEMP || HR || [sea]<math>^c</math>_water_temperature || degree_Celsius || TIME, N_T_SENSORS
|-
| ACC || O || platform_acceleration || m s-2 || TIME, N_ACC_SENSORS
|-
| CNDC || O || [sea]<math>^c</math>_water_electrical_conductivity || S m-1 || TIME_CTD, N_C_SENSORS
|-
| GRADT || O || derivative_of_[sea]<math>^c</math>_water_temperature_wrt_<math>^*d</math>|| degree_Celcius m-1 || TIME, N_GRADT_SENSORS
|-
| GRADC || O || derivative_of_[sea]<math>^c</math>_water_conductivity_wrt_<math>^*d</math> || - || TIME, N_GRADC_SENSORS
|-
| PITCH || O || platform_pitch_angle || degree || TIME
|-
| ROLL || O || platform_roll_angle || degree || TIME
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Level 2 data (shear probes)

2024-05-24T18:51:33Z

KikiSchulz:

Level 2 data, that is saved in the NetCDF group "L2_cleaned", are the full resolution, cleaned and despiked parameters from level 1. The initial data set is subdivided in [[Section|sections]] and labeled accordingly in the parameter SECTION_NUMBER with integers. Level 2 data is ready for estimating spectra. In addition to cleaned and despiked level 1 data channels, level 2 data comprises the additional parameter summarized in the table below.

It is important that the platform speed with respect to water, as used in the dissipation estimates, is included in this level. Also note that the shear probe time series (and optionally acceleration and vibration) must be cleaned and filtered as needed at this level, and will not be altered further when estimating dissipation rates.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME <math>^a</math> || length of the record from turbulence (fast) data channels
|-
|N_SHEAR_SENSORS ||number of shear channel (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> At this level platform speed must be provided. We require that this is given at the shear probe time (not TIME_SLOW or TIME_CTD. Please interpolate if needed.
<br>
<math>^b</math> Please use these examples for related sensors, e.g.:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors
</div>

=Variables=

<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME
|-
| VIB || HR || platform_vibration || m s-2, or -<math>^d</math> || TIME, N_VIB_SENSORS
|-
| ACC || O || platform_acceleration || m s-2, or -<math>^d</math> || TIME , N_ACC_SENSORS
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: Acceleration and vibration sensors are sometimes not calibrated and their records are used as raw values.
</div>

[[Category: Shear probes]]

------
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 1 data (shear probes)| Level 1 data]]<br>
go to next: [[Level 3 data (shear probes)| Level 3 data]].

Level 2 data (shear probes)

2024-05-24T18:48:24Z

KikiSchulz:

Level 2 data, that is saved in the NetCDF group "L2_cleaned", are the full resolution, cleaned and despiked parameters from level 1. The initial data set is subdivided in [[Section|sections]] and labeled accordingly in the parameter SECTION_NUMBER with integers. Level 2 data is ready for estimating spectra. In addition to cleaned and despiked level 1 data channels, level 2 data comprises the additional parameter summarized in the table below.

It is important that the platform speed with respect to water, as used in the dissipation estimates, is included in this level. Also note that the shear probe time series (and optionally acceleration and vibration) must be cleaned and filtered as needed at this level, and will not be altered further when estimating dissipation rates.

On all levels, "sea_water" in the standard name can be replaced by "water" for limnologic applications.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME <math>^a</math> || length of the record from turbulence (fast) data channels
|-
|N_SHEAR_SENSORS ||number of shear channel (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> At this level platform speed must be provided. We require that this is given at the shear probe time (not TIME_SLOW or TIME_CTD. Please interpolate if needed.
<br>
<math>^b</math> Please use these examples for related sensors, e.g.:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors
</div>

=Variables=

<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions#CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME
|-
| VIB || HR || platform_vibration || m s-2, or -<math>^d</math> || TIME, N_VIB_SENSORS
|-
| ACC || O || platform_acceleration || m s-2, or -<math>^d</math> || TIME , N_ACC_SENSORS
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: Acceleration and vibration sensors are sometimes not calibrated and their records are used as raw values.
</div>

[[Category: Shear probes]]

------
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 1 data (shear probes)| Level 1 data]]<br>
go to next: [[Level 3 data (shear probes)| Level 3 data]].

Level 1 data (shear probes)

2024-05-24T18:46:59Z

KikiSchulz:

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different from fast)
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Unit !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions#CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || HR|| platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| VIB || HR || platform_vibration || - || TIME, N_VIB_SENSORS
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure|| dbar || TIME
|-
| TEMP || HR || [sea]<math>^c</math>_water_temperature || degree_Celsius || TIME, N_T_SENSORS
|-
| ACC || O || platform_acceleration || m s-2 || TIME, N_ACC_SENSORS
|-
| CNDC || O || [sea]<math>^c</math>_water_electrical_conductivity || S m-1 || TIME_CTD, N_C_SENSORS
|-
| GRADT || O || derivative_of_[sea]<math>^c</math>_water_temperature_wrt_<math>^*d</math>|| degree_Celcius m-1 || TIME, N_GRADT_SENSORS
|-
| GRADC || O || derivative_of_[sea]<math>^c</math>_water_conductivity_wrt_<math>^*d</math> || - || TIME, N_GRADC_SENSORS
|-
| PITCH || O || platform_pitch_angle || degree || TIME
|-
| ROLL || O || platform_roll_angle || degree || TIME
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Level 2 data (shear probes)

2024-05-24T18:46:28Z

KikiSchulz:

Level 2 data, that is saved in the NetCDF group "L2_cleaned", are the full resolution, cleaned and despiked parameters from level 1. The initial data set is subdivided in [[Section|sections]] and labeled accordingly in the parameter SECTION_NUMBER with integers. Level 2 data is ready for estimating spectra. In addition to cleaned and despiked level 1 data channels, level 2 data comprises the additional parameter summarized in the table below.

It is important that the platform speed with respect to water, as used in the dissipation estimates, is included in this level. Also note that the shear probe time series (and optionally acceleration and vibration) must be cleaned and filtered as needed at this level, and will not be altered further when estimating dissipation rates.

On all levels, "sea_water" in the standard name can be replaced by "water" for limnologic applications.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME <math>^a</math> || length of the record from turbulence (fast) data channels
|-
|N_SHEAR_SENSORS ||number of shear channel (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> At this level platform speed must be provided. We require that this is given at the shear probe time (not TIME_SLOW or TIME_CTD. Please interpolate if needed.
<br>
<math>^b</math> Please use these examples for related sensors, e.g.:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors
</div>

=Variables=

<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Units of measurement !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions#CF-Convention]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || R || platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| SECTION_NUMBER || R || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME
|-
| VIB || HR || platform_vibration || m s-2, or -<math>^d</math> || TIME, N_VIB_SENSORS
|-
| ACC || O || platform_acceleration || m s-2, or -<math>^d</math> || TIME , N_ACC_SENSORS
|}
<math>^a</math> If using TIME_SLOW or TIME_ACC, this must be provided in addition to the TIME record.
</div>

[[Category: Shear probes]]

------
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 1 data (shear probes)| Level 1 data]]<br>
go to next: [[Level 3 data (shear probes)| Level 3 data]].

Level 1 data (shear probes)

2024-05-24T18:35:47Z

KikiSchulz:

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different from fast)
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Variable Name !! Req.<math>^a</math> !! Standard Name !! Unit !! Dimensions
|-
| TIME || R || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^b</math> || TIME
|-
| SHEAR || R || [sea]<math>^c</math>_water_velocity_shear || s-1 || TIME, N_SHEAR_SENSORS
|-
| PSPD_REL || HR|| platform_speed_wrt_[sea]<math>^c</math>_water || m s-1 || TIME
|-
| VIB || HR || platform_vibration || - || TIME, N_VIB_SENSORS
|-
| PRES || HR || [sea]<math>^c</math>_water_pressure|| dbar || TIME
|-
| TEMP || HR || [sea]<math>^c</math>_water_temperature || degree_Celsius || TIME, N_T_SENSORS
|-
| ACC || O || platform_acceleration || m s-2 || TIME, N_ACC_SENSORS
|-
| CNDC || O || [sea]<math>^c</math>_water_electrical_conductivity || S m-1 || TIME_CTD, N_C_SENSORS
|-
| GRADT || O || derivative_of_[sea]<math>^c</math>_water_temperature_wrt_<math>^*d</math>|| degree_Celcius m-1 || TIME, N_GRADT_SENSORS
|-
| GRADC || O || derivative_of_[sea]<math>^c</math>_water_conductivity_wrt_<math>^*d</math> || - || TIME, N_GRADC_SENSORS
|-
| PITCH || O || platform_pitch_angle || degree || TIME
|-
| ROLL || O || platform_roll_angle || degree || TIME
|}
<math>^a</math>: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
<br><math>^b</math>: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
<br><math>^c</math>: User can choose between water or sea_water depending on the environment
<br><math>^d</math>: wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Level 1 data (shear probes)

2024-05-24T18:14:54Z

KikiSchulz: /* Required Variables */

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different from fast)
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Variable Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^a</math> || TIME
|-
| SHEAR || sea_water_velocity_shear<br /> (or water_velocity_shear) || s-1 || [TIME, N_SHEAR_SENSORS]
|}
<math>^a</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Highly-recommended Level 1 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME <math>^a</math>
|-
| VIB<math>^b</math> || platform_vibration || NA || [TIME, N_VIB_SENSORS]
|-
| PRES<math>^c</math> || sea_water_pressure<br /> (water_pressure) || dbar || TIME <math>^a</math>
|-
| TEMP || sea_water_temperature<br /> (water_temperature) || degree_Celsius || [TIME <math>^a</math>, N_T_SENSORS]
|}
<math>^a</math> or TIME_SLOW or TIME_CTD
<br><math>^b</math> or ACC (see Table for optional variables)
<br><math>^c</math> for profiling instruments
</div>

=Optional Level 1 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| ACC || platform_acceleration || m s-2 || [TIME <math>^b</math>, N_ACC_SENSORS]
|-
| CNDC || sea_water_electrical_conductivity<br /> (water_electrical_conductivity) || S m-1 || [TIME_CTD <math>^b</math>, N_C_SENSORS]
|-
| GRADT || derivative_of_seawater_temperature_wrt_z <math>^c</math>|| degree_Celcius m-1 || [TIME, N_GRADT_SENSORS]
|-
| GRADC || derivative_of_seawater_conductivity_wrt_z <math>^c</math> || Typically not calibrated|| [TIME, N_GRADC_SENSORS]
|-
| PITCH || platform_pitch_angle || degree || TIME <math>^a</math>
|-
| ROLL || platform_roll_angle || degree || TIME <math>^a</math>
|}
<math>^a</math> or TIME_SLOW or TIME_CTD
<br><math>^b</math> or TIME_SLOW
<br><math>^c</math> or wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Level 1 data (shear probes)

2024-05-24T18:05:39Z

KikiSchulz:

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different from fast)
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically TIME is assumed for the fast-sampled microstructure channels. Use, e.g., TIME_SLOW or TIME_CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^a</math> || TIME
|-
| SHEAR || sea_water_velocity_shear<br /> (or water_velocity_shear) || s-1 || [TIME, N_SHEAR_SENSORS]
|}
<math>^a</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Highly-recommended Level 1 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME <math>^a</math>
|-
| VIB<math>^b</math> || platform_vibration || NA || [TIME, N_VIB_SENSORS]
|-
| PRES<math>^c</math> || sea_water_pressure<br /> (water_pressure) || dbar || TIME <math>^a</math>
|-
| TEMP || sea_water_temperature<br /> (water_temperature) || degree_Celsius || [TIME <math>^a</math>, N_T_SENSORS]
|}
<math>^a</math> or TIME_SLOW or TIME_CTD
<br><math>^b</math> or ACC (see Table for optional variables)
<br><math>^c</math> for profiling instruments
</div>

=Optional Level 1 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| ACC || platform_acceleration || m s-2 || [TIME <math>^b</math>, N_ACC_SENSORS]
|-
| CNDC || sea_water_electrical_conductivity<br /> (water_electrical_conductivity) || S m-1 || [TIME_CTD <math>^b</math>, N_C_SENSORS]
|-
| GRADT || derivative_of_seawater_temperature_wrt_z <math>^c</math>|| degree_Celcius m-1 || [TIME, N_GRADT_SENSORS]
|-
| GRADC || derivative_of_seawater_conductivity_wrt_z <math>^c</math> || Typically not calibrated|| [TIME, N_GRADC_SENSORS]
|-
| PITCH || platform_pitch_angle || degree || TIME <math>^a</math>
|-
| ROLL || platform_roll_angle || degree || TIME <math>^a</math>
|}
<math>^a</math> or TIME_SLOW or TIME_CTD
<br><math>^b</math> or TIME_SLOW
<br><math>^c</math> or wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Benchmark datasets for shear probes

2023-10-11T20:59:36Z

KikiSchulz:

These datasets can be accessed from a [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAgL55HqB50DQd2J11m7kl9a?dl=0|read-only dropbox folder], and will eventually be housed at the BODC center with a DOI.

We provide a number of matlab routines to read in and compare data from grouped NetCDF files that follow our recommended structure on our [https://github.com/SCOR-ATOMIX/shear-probes GitHub repository]. The Matlab function ATOMIX_load.m there can be used to load a benchmark data file..

{| class="wikitable sortable"
|-
! Filename Prefix
! Platform
! Instrument
! Region
! PI (ATOMIX)
! Comment
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAajUI9HIodADTYRJSfYb3ba/VMP250_TidalChannel/VMP250_TidalChannel_024.nc?dl=0 VMP250_TidalChannel_024]
| Ship
| VMP-250
| Haro Strait
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAD3PcHlwHjyrMAA7er6jRG_a/EPSIFISH_BLT_NORTHATL/epsifish_epsilometer_blt_north_atl.nc?dl=0 EPSILOMETER_RockallTrough]
| Ship
| Epsilometer
| Rockall Trough
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AABKhtIRZSuuZSfwTJ3xNNaNa/VMP2000_FaroeBankChannel/VMP2000_FaroeBankChannel.nc?dl=0 VMP2000_FaroeBankChannel]
| Ship
| VMP-2000
| Faroe Bank Channel (North Atlantic)
| Fer
| ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAniGJlY-bwRplaiAV8AxC2a/MSS_BalticSea/MSS_Baltic_0330.nc?dl=0 MSS_BalticSea]
| Ship
| MSS
| Baltic Sea
| Holtermann
|
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AADqZw8zwf93HpZMhF8MWAd-a/Nemo_MR1000_Minas_Passage/Nemo_MR1000_Minas_Passage_InStream.nc?dl=0 Nemo_MR1000_Minas_Passage_InStream]
| Mooring
| MicroRider
| Minas Passage (Bay of Fundy, NS)
| Lueck
| a swift tidal channel. Dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]

Benchmark datasets for shear probes

2023-10-11T20:58:32Z

KikiSchulz:

These datasets can be accessed from a [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAgL55HqB50DQd2J11m7kl9a?dl=0|read-only dropbox folder], and will eventually be housed at the BODC center with a DOI.

We provide a number of matlab routines to read in and compare data from grouped NetCDF files that follow our recommended structure on our [https://github.com/SCOR-ATOMIX/shear-probes|GitHub repository]. The Matlab function ATOMIX_load.m there can be used to load a benchmark data file..

{| class="wikitable sortable"
|-
! Filename Prefix
! Platform
! Instrument
! Region
! PI (ATOMIX)
! Comment
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAajUI9HIodADTYRJSfYb3ba/VMP250_TidalChannel/VMP250_TidalChannel_024.nc?dl=0 VMP250_TidalChannel_024]
| Ship
| VMP-250
| Haro Strait
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAD3PcHlwHjyrMAA7er6jRG_a/EPSIFISH_BLT_NORTHATL/epsifish_epsilometer_blt_north_atl.nc?dl=0 EPSILOMETER_RockallTrough]
| Ship
| Epsilometer
| Rockall Trough
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AABKhtIRZSuuZSfwTJ3xNNaNa/VMP2000_FaroeBankChannel/VMP2000_FaroeBankChannel.nc?dl=0 VMP2000_FaroeBankChannel]
| Ship
| VMP-2000
| Faroe Bank Channel (North Atlantic)
| Fer
| ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAniGJlY-bwRplaiAV8AxC2a/MSS_BalticSea/MSS_Baltic_0330.nc?dl=0 MSS_BalticSea]
| Ship
| MSS
| Baltic Sea
| Holtermann
|
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AADqZw8zwf93HpZMhF8MWAd-a/Nemo_MR1000_Minas_Passage/Nemo_MR1000_Minas_Passage_InStream.nc?dl=0 Nemo_MR1000_Minas_Passage_InStream]
| Mooring
| MicroRider
| Minas Passage (Bay of Fundy, NS)
| Lueck
| a swift tidal channel. Dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]

Level 4 data (shear probes)

2023-10-11T20:54:33Z

KikiSchulz: moved kmin from optional to required

Level 4 data include the final dissipation estimates as time series, as well as indicators for the quality and accuracy of the estimates and additional derived parameters. It is saved in the NetCDF group "L4_dissipation". Each dissipation estimate in level 4 corresponds to a spectrum in the level 3 data. Consequently, the level 3 and 4 TIME dimensions are the same. Parameter EPSI_FINAL is the final dissipation rate estimate, averaged of the selected estimates (using the [[Quality_control_coding | QC flags]]) at that depth.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|}
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimensions
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^c</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section _of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA ||
|-
| EPSI || specific_turbulent_kinetic_energy_dissipation _in_water || W kg-1 || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_FINAL || specific_turbulent_kinetic_energy_dissipation _in_water || W kg-1 || TIME_SPECTRA
|-
| KMIN || minimum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| KMAX || maximum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| N_S || number_of_spectral_points_used_for_estimating_turbulent_kinetic_energy_dissipation || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_FLAGS <math>^a</math> || dissipation_qc_flags || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| METHOD <math>^b</math>|| method_used_for_estimating_ turbulent_kinetic_energy_dissipation || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|}
<math>^a</math> Quality control coding for the final dissipation estimate.

<math>^b</math> METHOD=0 for spectral integration, METHOD=1 for fitting to the inertial subrange.

<math>^c</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Optional Level 4 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| KVISC || kinematic_viscosity_of_water || m2 s-1 || TIME_SPECTRA
|-
| FOM || figure_of_merit || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| MAD || mean_absolute_deviation || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| VAR_RESOLVED || variance_resolved || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_STD || expected_standard_deviation_of_the_ logarithm_of_the_dissipation_estimate || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| DESPIKE_FRACTION_SH || fraction_of_shear_data_modified_by_despiking_algorithm || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| DESPIKE_PASS_COUNT_SH || number_of_despike_passes_for_shear_probes || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|}

</div>

-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 3 data (shear probes)| Level 3 data]].
[[Category:Shear probes]]

Shear probes

2023-09-29T21:02:57Z

KikiSchulz:

== Welcome to the shear probe group! ==

The shear probe group addresses best practices in obtaining dissipation rate estimates from shear probes using a platform-independent approach. Our recommendations are applicable for measurements from probes attached to e.g., conventional gravity-driven loose-tether vertical profilers, ocean gliders, autonomous underwater vehicles (AUVs), or autonomous self-propelled floats (e.g. SOLO).

== Scope ==

The shear probe group provides the following:

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:Flowchart symbol.png|180px|link=Flow chart for shear probes|Flow chart for shear probes]]
|[[File:M Rider Glider 1.JPG|250px|link=Dataset requirements for shear probes|Dataset requirements for shear probes]]
|[[File:MSS ADCP CTD (Schaffer).JPG|250px|link=Tentative benchmarks for shear probes|Benchmark datasets for shear probes]]
|-
|[[Flow chart for shear probes|Flow chart for <br>data processing]]
|[[Dataset requirements for shear probes | Dataset requirements <br>and format description]]
|[[Benchmark datasets for shear probes | Benchmark <br>datasets]]
|}

[[Category: Shear probes]]

-----
Return [[Main Page]]

File:Flowchart symbol.png

2023-09-29T21:00:50Z

KikiSchulz: Symbolic representation of a data processing flowchart

== Summary ==
Symbolic representation of a data processing flowchart

Main Page

2023-04-05T19:38:04Z

KikiSchulz:

__NOTOC__
== Welcome to the ATOMIX wiki! ==
This wiki was initially developed by the [https://scor-int.org/group/analysing-ocean-turbulence-observations-to-quantify-mixing-atomix/ SCOR working group 160] - Analysing ocean turbulence observations to quantify mixing (ATOMIX). It is meant to consolidate knowledge about oceanic turbulence data acquisition and processing, and to provide guidelines for processing and publication of data sets aimed at both experienced and new users.

[https://landing.mailerlite.com/webforms/landing/e4j3z7 Please sign up to our mailing list!]

== Wiki structure ==
This wiki is organized to provide a best practice for turbulence data processing from the three main instruments used for this purpose. Below, you can select your preferred device and navigate to the corresponding subpage.

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:VMP500-CookSt.JPG|250px|link=Shear probes|Shear probes]]
|[[File:AdcpMTOrig.png|250px|link=Velocity profilers|Velocity profilers]]
|[[File:TIC Leopold 1.jpg|120px|link=Velocity point-measurements|Velocity point-measurements]]
|-
|[[Shear probes]]
|[[Velocity profilers]]
|[[Velocity point-measurements]]
|}

These three individual processing guidelines share the same [[Nomenclature]] and [[NetCDF parameter]] attributes.

== Turbulence Sensing Gallery ==
We also have the [[ATOMIX Gallery]] with images illustrating various sampling configurations and instruments.

== Members of the SCOR Working Group ATOMIX ==
Chairs: <br>
Cynthia Bluteau (Canada), Ilker Fer (Norway), Yueng-Djern Lenn (UK) <br><br>

Other Full Members:<br>
Toshiyuki Hibiya (Japan), Arnaud LeBoyer (USA), Zhiyu Liu (China), Rolf Lueck (Canada), Amelie Meyer (Australia), Craig Stevens (New Zealand), Danielle Wain (USA)<br><br>

Associate Members:<br>
Marcus Dengler (Germany), Jenson George (India), Peter Holtermann (Germany), Ryuichiro Inoue (Japan), Natasha Lucas (UK), Justine McMillan (Canada), Stephen Monismith (USA), Julia Mullarney (New Zealand), Sarah Nicholson (South Africa), Kirstin Schulz (USA)<br><br>

== For new ATOMIX wiki users ==
This wiki is meant to be dynamic and grow with the advances achieved in the scientific turbulence community. To be successful, your active contribution to this effort is needed!
* [[The scope and approach of the ATOMIX wiki]].
* Please visit the [[How to use and contribute|contribute]] page to learn how to comment and edit these pages.
* Consult the [https://www.mediawiki.org/wiki/Special:MyLanguage/Help:Contents User's Guide] for information on using the wiki software.

Iterative spectral integration algorithm

2023-02-03T15:37:48Z

KikiSchulz:

Spectral integration is an iterative procedure because the bandwidth required to estimate the variance of shear depends on the rate of dissipation, the level of electronic noise in the shear-probe signal, on the wavenumber of spurious signals that were not removed by the Goodman
<ref name="goodmanetal2006">{{Cite journal
|authors= L. Goodman, E. Levine, and R. Lueck
|journal_or_publisher= J. Atmos. Oceanic Technol.
|paper_or_booktitle= On measuring the terms of the turbulent kinetic energy budget from an AUV
|year= 2006
|doi= 10.1175/JTECH1889.1
}}</ref>
algorithm, and on the wavenumber resolution of the shear probe.
The rate of dissipation is estimated using

<math>
\begin{equation}
\varepsilon = \frac{15}{2} \nu \int^{k_u}_{k_0} \Psi(k) dk
\end{equation}
</math>

where <math>\Psi(k)</math> is the dimensional shear spectrum.
The lower limit of spectral integration is often set to <math>k_0=0\ \mathrm{cpm}</math> although it can also be set to the lowest non-zero wavenumber of a spectrum.
The spectrum at zero wavenumber, <math>\Psi(0)</math>, is usually set to zero and it should be small if the spectrum is estimated properly.

The upper limit of integration, <math>k_u</math>, is set by the smallest of a number of criteria that are listed next.

(1) The wavenumber range that is dominated by electronic noise can usually be determined from a minimum in the spectrum. Real shear is at wavenumbers smaller than this minimum while electronic noise is usually at higher wavenumbers. The spectral minimum may be found by fitting a low-order polynomial to the spectrum in log-log space. Third order is often sufficient. The wavenumber of the spectral minimum, <math>k_{\mathrm{min}}</math>, sets one of the limits on <math>k_u</math>.

(2) Another upper limit is <math>k_{150} = 150\ \mathrm{cpm}</math> that is imposed by the spatial resolution of a commonly used shear probe.
You may use a different value if your shear probe has a spatial resolution different from that reported by Macoun and Lueck, 2004<ref name="macounlueck2004">{{Cite journal
|authors= P. Macoun and R. Lueck
|journal_or_publisher= J. Atmos. Oceanic Technol.
|paper_or_booktitle= Modelling the spatial response of the airfoil shear probe using different sized probes
|year= 2004
|doi= 10.1175/1520-0426(2004)021
}}</ref>
At the wavenumber of <math>150\ \mathrm{cpm}</math> the spectrum derived from the commonly used shear probe is boosted by a factor of 10.
At higher wavenumbers the spectral correction is more than a actor of 10 and such large corrections are not recommended.

(3) The cut-off frequency, <math>f_A</math>, of the anti-aliasing filter used by the shear-probe sampler sets another upper limit of spectral integration, namely <math>k_A \leq f_A/U</math>.
Because most filters have a transition range from passing to attenuating a signals, it is wise to set this limit to value slightly smaller than the cut-off frequency.
For example, <math>k_A \leq 0.9\, f_A/U</math>.

(4) The user may impose an upper limit to exclude wavenumbers that have contaminations that are not correctable, <math>f_{\mathrm{lim}}</math>.
For most instruments this limit is usually set to <math>\infty</math>, but it may be prudent to set this limit to a finite value in some cases.

(5) The final wavenumber limit, <math>k_{95}</math>, is the wavenumber at which the variance of shear is resolved to 95%.
There is not incentive to integrate the spectrum beyond this limit because the correction that must be applied amounts to only 5%.
This wavenumber is <math> k_{95} = 0.12\, (\varepsilon/\nu^4)^{1/4} </math> and the factor of <math>0.12</math>, is nearly identical for all of the common approximations to the shear spectrum, such as the approximations to the Nasmyth
<ref name="wolketal2002">{{Cite journal
|authors= F. Wolk, H. Yamazaki, L. Seuront, L., and R. Lueck
|journal_or_publisher= J. Atmos. Oceanic Technol.
|paper_or_booktitle= A new free-fall profiler for measuring biophysical microstructure
|year= 2002
|doi= 10.1175/1520-0426(2002)019
}}</ref>
<ref name="oakey1982">{{Cite journal
|authors= N. Oakey
|journal_or_publisher= J. Phys. Oceanogr.
|paper_or_booktitle= Determination of the Rate of Dissipation of Turbulent Kinetic Energy from Simultaneous Temperature and Velocity Shear Microstructure Measurements
|year= 1982
|doi= 10.1175/1520-0485(1982)012
}}</ref>
<ref name="lueck2022b">{{Cite journal
|authors= R. Lueck
|journal_or_publisher= J. Atmos. Oceanic Technol.
|paper_or_booktitle= The statistics of turbulence measurements. Part 2: Shear spectra and a new spectral model Shear spectra and a new spectral model
|year= 2022
|doi= 10.1175/JTECH-D-21-0050.1
}}</ref>
, the Panchev-Kesich
<ref name="panchevkesich1969">{{Cite journal
|authors= S. Panchev and D. Kesich
|journal_or_publisher= Comptes rendus de lacademie Bulgare des sciences
|paper_or_booktitle= Energy spectrum of isotropic turbulence at large wavenumbers
|year= 1969
|doi= unknown
}}</ref>
, and the Lueck
<ref name="lueck2022b"></ref>
non-dimensional universal spectra.

Thus, the upper limit of spectral integration is

<math>k_u = \mathrm{min}(k_{\mathrm{min}},\ k_{150},\ 0.9k_A,\ k_{\mathrm{lim}},\ k_{95}) </math>.

The last of these upper limits, <math>k_{95}</math>, presents us with a conundrum because it requires the rate of dissipation which is what we are trying to estimate by way of the integration of the shear spectrum.
Clearly, we need to bootstrap this process by starting with a reasonable (but certainly a rough) estimate of the rate of dissipation.

The wavenumber range of the spectrum of shear depends on the rate of dissipation.
The spectrum broadens in proportion to <math>\epsilon^{1/4}</math> and the spectrum rises in proportion to <math>\epsilon^{3/4}</math>. Thus, the fraction of the shear variance that is resolved at any particular wavenumber depends on the rate of dissipation.

However, the non-dimensional spectrum

<math>G(\hat k) = \frac{L^2_k}{(\varepsilon \nu^5)^{1/4}} S(k)</math>

where <math>\hat k=kL_k</math> and <math>L_k=(\nu^3/\varepsilon)^{1/4}</math> is the Kolmogorov length, is expected to be universal and independent of the rate of dissipation.
There are several analytic models of the non-dimensional spectrum that are based on approximations of empirically derived spectra such as Wolk et al (2002)
<ref name="wolketal2002">{{Cite journal
|authors= F. Wolk, H. Yamazaki, L. Seuront, L., and R. Lueck
|journal_or_publisher= J. Atmos. Oceanic Technol.
|paper_or_booktitle= A new free-fall profiler for measuring biophysical microstructure
|year= 2002
|doi= 10.1175/1520-0426(2002)019
}}</ref>
who provides an approximation to the Nasmyth spectrum
<ref name="oakey1982">{{Cite journal
|authors= N. Oakey
|journal_or_publisher= J. Phys. Oceanogr.
|paper_or_booktitle= Determination of the Rate of Dissipation of Turbulent Kinetic Energy from Simultaneous Temperature and Velocity Shear Microstructure Measurements
|year= 1982
|doi= 10.1175/1520-0485(1982)012
}}</ref>
and Lueck (2022)
<ref name="lueck2022b">{{Cite journal
|authors= R. Lueck
|journal_or_publisher= J. Atmos. Oceanic Technol.
|paper_or_booktitle= The statistics of turbulence measurements. Part 2: Shear spectra and a new spectral model Shear spectra and a new spectral model
|year= 2022
|doi= 10.1175/JTECH-D-21-0050.1
}}</ref>
who provides an improved approximation to the Nasmyth spectrum, an approximation to the Panchev-Kesich (1975)
<ref name="panchevkesich1969">{{Cite journal
|authors= S. Panchev and D. Kesich
|journal_or_publisher= Comptes rendus de lacademie Bulgare des sciences
|paper_or_booktitle= Energy spectrum of isotropic turbulence at large wavenumbers
|year= 1969
|doi= unknown
}}</ref>
spectrum, and a new approximation based on 14,600 dimensional spectra.

These spectral approximations also provide the fraction of the shear variance that is resolved at any particular non-dimensional wavenumber. For all of these analytic approximations, 95% of the variance of shear is resolved at a non-dimensional wavenumber of approximately 0.12. There is little motivation for integrating the spectrum beyond this wavenumber. This sets another upper limit to spectral integration once the rate of dissipation is known, or at least known approximately.

The upper limit of spectral integration is nearly always higher than 10 cpm. For example, when <math>\varepsilon=1\times 10^{-10}\ \mathrm{W\, kg^{-1}}</math>, this limit resolves a little more than 95% of the shear variance. Less for larger dissipation rates. Thus, if we integrate a shear spectrum to 10 cpm this variance must be related to the total variance if the spectrum follows a universal form. In fact, if the measured spectrum follows the universal form exactly, then the ratio of the “true” dissipation rate, <math>\varepsilon</math>, to the rate derived from integration to 10 cpm, <math>\varepsilon_{10}</math>, is given by

<math>
\frac{\varepsilon}{\varepsilon_{10}} = \sqrt{1+a\varepsilon_{10}} + \exp\left(-b\,\varepsilon_{10}\right) - 1
</math>

where

<math>
\begin{split}
a &= 1.25\times 10^{-9}\, \nu^{-3} \\
b &= 5.5\times 10^{-8}\, \nu^{-5/2} \\
\varepsilon_{10} &= \frac{15}{2}\, \nu\, \int_0^{10} \Psi(k)\, \mathrm{d}k\\
\varepsilon &= \frac{15}{2}\, \nu\, \int_0^{\infty} \Psi(k)\, \mathrm{d}k \ \ .
\end{split}
</math>

Thus, integrating the spectrum, <math>\Psi</math>, to 10 cpm provides the first (and quite rough) estimate of the rate of dissipation and this estimate can be used to set another upper limit to spectral integration. That is, at what wavenumber is 95% of the spectrum resolved if the dissipation rate equals this initial estimate?

[[File:Figure 381.jpg|thumb|500px|The ratio of the true dissipation rate to the rate determined by integrating the spectrum to only 10 cpm, as a function of the 10-cpm rate for a range of kinematic viscosities, if the measured spectrum follows the Nasmyth spectrum.]]

The spectrum is then integrated to the lowest of these upper limits to provide an improved estimate of the rate of dissipation. It is an improved estimate because it will nearly always span a range of wavenumbers that is considerably wider than 10 cpm, which improves its statistical reliability. This improved estimate is then used to determine the fraction of the shear variance that is resolved by the upper limit of integration. The estimate is divided by this fraction to form a new estimate of <math>\varepsilon</math> This process is then repeated -- find the new fraction resolved, adjust the estimate upwards using this fraction, and so on. This iteration converges quickly because the wavenumber is non-dimensionalized by <math>\varepsilon^{1/4}</math>. If the fraction of the variance resolved by a particular <math>k_u</math> exceeds 50%, the estimate of the rate of dissipation converges to within 1% of its ultimate value in two or fewer iterations.

For very high rates of dissipation, such as <math>\varepsilon=1\times 10^{-5}\ \mathrm{W\, kg^{-1}}</math>, the shear-probe cannot fully resolve the spectrum of shear. We recommend to estimate the rate by fitting to the spectrum in the inertial subrange.

In this range, the spectrum rises in proportion to <math>\varepsilon^{2/3}k^{1/3}</math> and, thus, its level provides an estimate of the rate of dissipation. The inertial subrange is confined to wavenumbers smaller than <math>k(\nu^3/\varepsilon)^{1/4}=0.02</math>, and thus will usually use fewer spectral points than the method of spectral integration. This reduces the statistical reliability of the dissipation estimate but it does avoid the bias introduced by not fully resolving the spectrum of shear.

<math></math>

==References==
<references />

----------------------------
return to [[Flow chart for shear probes]]

[[Category:Shear probes]]

User:KikiSchulz

2021-12-30T17:26:05Z

KikiSchulz: Created page with "Kirstin Schulz - Research Fellow at the University of Texas at Austin Hi, I am a Kiki, part-time sea-going oceanographer, part time numerical modele..."

[[File:Kirstin.jpg|thumb|Kirstin Schulz - Research Fellow at the University of Texas at Austin]]
Hi, I am a Kiki, part-time sea-going oceanographer, part time numerical modeler. I work at the University of Texas at Austin, in The Computational Research in Ice and Ocean group ([https://crios-ut.github.io/ CRIOS]) group. My area of research is the Arctic Ocean and Greenland, where glaciers meet the ocean - check out our [https://griso.ucsd.edu/ GRISO] project website.

I was involved in the oceanic turbulence measurements during the MOSAiC drift campaign, from sitting on the ice and measuring to processing and publishing the obtained data.

File:Kirstin.jpg

2021-12-30T17:24:57Z

KikiSchulz: Kiki profile pic

== Summary ==
Kiki profile pic

Shear probes

2021-11-09T23:00:46Z

KikiSchulz:

== Welcome to the shear probe group! ==

The shear probe group addresses best practices in obtaining dissipation rate estimates from shear probes using a platform-independent approach. Our recommendations are applicable for measurements from probes attached to e.g., conventional gravity-driven vertical profilers, gliders, AUVs, or autonomous self-propelled floats.

== Scope ==

The shear probe group provides the following:

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:VMP500-CookSt.JPG|250px|link=Flow chart for shear probes|Flow chart for shear probes]]
|[[File:M Rider Glider 1.JPG|250px|link=Dataset requirements for shear probes|Dataset requirements for shear probes]]
|[[File:MSS ADCP CTD (Schaffer).JPG|250px|link=Benchmark datasets for shear probes|Benchmark datasets for shear probes]]
|-
|[[Flow chart for shear probes|Flow chart for data processing]]
|[[Dataset requirements for shear probes | Dataset requirements]]
|[[Benchmark datasets for shear probes | Benchmark datasets]]
|}

[[Category: Shear probes]]

-----
Return [[Main Page]]

Talk:Flow chart for shear probes

2021-11-09T22:46:23Z

KikiSchulz:

Step 2: Shall we change the term "Profile"? (--[[User:Aleboyer|Aleboyer]] ([[User talk:Aleboyer|talk]]) 14:00, 25 June 2021 (CEST))

Re: Arnaud - I think we settled this section (includes profile but more general) and segment (for one diss rate estimate) thing - so no ;) [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 15:44, 9 November 2021 (CET)

Other comment: could we get rid of some 'shear probes' in the subheadings? It is unnecessary, repetative and makes the table of content ugly because it is long. [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 15:44, 9 November 2021 (CET)[[User:Ilker|Ilker]] ([[User talk:Ilker|talk]]) 16:09, 9 November 2021 (CET)Agreed

[[User:Ilker|Ilker]] ([[User talk:Ilker|talk]]) 16:09, 9 November 2021 (CET) We need a "Determine the temperature of the water" page and a brief description why we need it (calculation of viscosity) and how we measure (FP07- beware drift; precision T sensor, or just assume a reasonable value for the environment).
:: I will create page and hope someone fills it with content. [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 22:47, 9 November 2021 (CET)

Coherent-vibration removal: more details can be included, e.g. the need for long segments for cross-spectral analysis and other recommendations [[User:Ilker|Ilker]] ([[User talk:Ilker|talk]]) 21:14, 9 November 2021 (CET)

Let's use numbered list (instead of bullets) for section content. It will be easier to refer to (in text or in an eventual graphics). Also note duplicate similar page and info (despiking parameters in choose parameters and despiking shear probe data in compute...) [[User:Ilker|Ilker]] ([[User talk:Ilker|talk]]) 21:45, 9 November 2021 (CET)
:: What to do with duplicate pages? I would advocate to remove them, or fill them with non-duplicate content, but this is quite a big decision to make. [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 22:47, 9 November 2021 (CET)

Another to do: see the extensive material in the "here" page (access from special pages - all pages). We must split these into shorter fundamentals. [[User:Ilker|Ilker]] ([[User talk:Ilker|talk]]) 21:45, 9 November 2021 (CET)
:: I've already extracted Pope and Nasmyth spectrum form "here" into fundamentals.[[User:Ilker|Ilker]] ([[User talk:Ilker|talk]]) 22:01, 9 November 2021 (CET)
:: I have put the first four subheadings of [[here]] to fundamentals and linked the 'next' page at the bottom of each page. I do not know what to do with the last subsection - does Lueck 2021a count as fundamental, or shall we add somewhere a 'recent developments' access point for pages? [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 23:46, 9 November 2021 (CET)

Talk:Here

2021-11-09T22:30:04Z

KikiSchulz:

* The pages title is not descriptive of the topic. It also covers too many topics, some of which are concepts that need breaking up. [[User:CynthiaBluteau|CynthiaBluteau]] ([[User talk:CynthiaBluteau|talk]]) 17:19, 20 May 2021 (CEST)

* Agreed the content here would be better placed into several Concept and a Fundamentals page. Nonetheless is may be useful as a repository of knowledge for now. However, as a WIP, I think it should not currently be linked to any landing page [[User:YuengLenn|Yueng Lenn]] ([[User talk:YuengLenn|talk]]) 20 May 2021 (CEST)

* I agree completely. Feel free to break it up into sub-pages. Using "here" was just a way to get started. This is my first Wiki document and it provided me with a chance to learn how to create a page. However, we do need to provide background information on what we know about the spectrum of shear (and strain) in a turbulent flow, because estimating a spectrum is the principle method of estimating dissipation rates. [[User:RolfLueck|RolfLueck]] ([[User talk:RolfLueck|talk]]) 12:19 May 20 2021 (PDT)

* Would it be an idea to subdivide by subheading (Spectra of velocity etc.) and add to [[Category:Fundamentals]], where already a page called [[Spectrum]] is? [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 23:03, 9 November 2021 (CET) Update: I will do that but keep the [[Here]] page for now. [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 23:04, 9 November 2021 (CET)

* I created four new fundamental pages, an at each page end I added to link to the logical next page to read, for people that just browse around. I have not yet added a fundamental page for the last subheading, as this is new research rather than a fundamental (right?) and I do not know how to deal with it. [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 23:30, 9 November 2021 (CET)

* Also, we do need many more hyperlinks and cross-refs everywhere. [[User:KikiSchulz|KikiSchulz]] ([[User talk:KikiSchulz|talk]]) 23:30, 9 November 2021 (CET)

Spectra in the inertial subrange

2021-11-09T22:27:30Z

KikiSchulz:

{{DefineConcept
|description=In the inertial subrange, the three-dimensional velocity spectrum follows a power-law behaviour and this makes it possible to easily derive the one-dimensional spectra, in this range
|article_type=Fundamentals
}}
In the inertial subrange, the three-dimensional velocity spectrum follows a power-law behaviour and this makes it possible to easily derive the one-dimensional spectra, in this range. Using ( ?) within the inertial subrange gives

<math> \tilde{F}_{11} (\hat{\kappa}_1) = \int_{\hat{\kappa}_1}^{\infty} \frac{F(\hat{\kappa})}{\hat{\kappa}} \left(1 - \frac{\hat{\kappa}_1^2}{\hat{\kappa}^2} \right)\, \mathrm{d}\hat{\kappa} = \frac{18}{55} C \hat{\kappa}_1^{-5/3} = C_1 \hat{\kappa}_1^{-5/3} </math>

where <math>C_1=18C/55\approx27/55</math> is frequently called the one-dimensional Kolmogorov constant, and the tilde is used to indicate these equations apply only in the inertial subrange.
It is not possible to measure the three-dimensional spectrum and, thus, it is not possible to estimate <math>C</math> directly.
Consequently, there is research interest in estimating </math>C_1</math> because it is the only practical way to determine the three-dimensional Kolmogorov constant <math>C</math>.
Sreenivasa (1995)<ref name=“Sreenivasan”> Sreenivasan, K. R. (1995). On the universality of the Kolmogorov constant. Physics of Fluids, 7(11), 2778-2784.</ref> compiled the values of the one-dimensional Kolmogorov constant reported from a wide range of measurements in the atmosphere, ocean, wind tunnels and pipes.
The mean value (excluding low Reynolds number measurements) is <math>0.53</math> and the standard deviation is <math>0.055</math> (Figure 1).
A crude estimate of the <math>95\%</math> confidence interval is <math>C_1=0.53\pm0.03</math>.

[[File:Sreenivasan2.png|frame| center|Figure 1. Figure 3 from Sreenivasa (1995)<ref name=“Sreenivasan”/> for the estimates of the one-dimensional Kolmogorov constant, <math>C_1</math>, derived from experimental measurements of along-stream velocity measurements and/or the rate of strain.]]

Using <math>\tilde{F}_{22}= \frac{4}{3} \tilde{F}_{11}</math>, the one-dimensional spectrum for the velocity components that are orthogonal to the direction of profiling is

<math> \tilde{F}_{22} (\hat{\kappa}_1) = \frac{4}{3} C_1 \hat{\kappa}_1^{-5/3} </math>

The gradient spectra in the inertial subrange are

<math>
\begin{equation}
\tilde{G}_{11} (\hat{\kappa}_1) = C_1 \hat{\kappa}_1^{1/3}
\end{equation}
</math>

and

<math>
\begin{equation}
\tilde{G}_{22} (\hat{\kappa}_1) = \frac{4}{3} C_1 \hat{\kappa}_1^{1/3}
\end{equation}
</math>

You want more? Go to [[Spectral integration]]

Spectral integration

2021-11-09T22:26:17Z

KikiSchulz: Created page with "{{DefineConcept |description=Estimating <math>\varepsilon</math> by spectral integration. |article_type=Fundamentals }} The shear probe provides a measure of the turbulent she..."

{{DefineConcept
|description=Estimating <math>\varepsilon</math> by spectral integration.
|article_type=Fundamentals
}}
The shear probe provides a measure of the turbulent shear, and this data can be used to estimate the spectrum of the shear.
The variance of shear is often estimated by integrating the spectrum of shear, namely

<math>\varepsilon = \frac{15}{2}\nu \overline{\left(\frac{\partial u}{\partial z} \right)^2} \equiv \frac{15}{2}\nu \int_0^{\infty} \Phi(k) \,\mathrm{d}k \approx \frac{15}{2}\nu \int_0^{k_u} \Phi(k) \,\mathrm{d}k </math>

where <math>\Phi</math> is an estimate of the spectrum of shear, <math>\Psi</math>, and the upper limit of spectral integration, <math>k_u</math>, is imposed by practical considerations.
Thus, only a fraction of the shear variance is resolved by this method.
There is value in having a mathematical approximation for the spectrum of shear and for the fraction of the variance that is resolved by integration to a finite upper wavenumber.
The model spectrum provides a gauge for judging the quality of the estimate of the spectrum.
The model of its integral provides a means to correct (upwards) the estimate of <math>\varepsilon</math> provided by spectral integration up to a finite wavenumber. Details of spectral integration are discussed [[here|not a good link needs attention]].

Units of a wavenumber spectrum

2021-11-09T22:23:47Z

KikiSchulz: Created page with "{{DefineConcept |description=There are two commonly used units for a wavenumber and it is important to be clear about which one you are using because the level of a spectrum d..."

{{DefineConcept
|description=There are two commonly used units for a wavenumber and it is important to be clear about which one you are using because the level of a spectrum depends on the unit.
|article_type=Fundamentals
}}
Mathematicians and theoreticians usually use ‘angular’ units expressed in radians and this should be indicated by <math>\mathrm{rad\, m^{-1}}</math> -– radians per meter.
It is the counterpart to frequency expressed in <math>\mathrm{rad\, s^{-1}}</math> -– radians per second.
Never express the units as <math>\mathrm{m^{-1}}</math> just because an angle technically has no units.
This usage is ambiguous.
The other unit, which is preferred by investigational scientists because it is derived naturally by a Fourier transform, among other reasons, is <math>\mathrm{cpm}</math> -– cycles per meter.
It is the counterpart of <math>\mathrm{Hz}</math> -– cycles per second.
The two measures of wavenumber differ by a factor of <math>2\pi</math> which is not small compared to one.
Here we use the symbol <math>\kappa</math> to indicate a wavenumber expressed in units of <math>\mathrm{rad\, m^{-1}}</math>, and we use the symbol <math>k</math> to indicate a wavenumber in units of <math>\mathrm{cpm}</math>.
Their relationship is

<math> \kappa = 2 \pi k </math>

Regardless of the unit of wavenumber that you employ, the integral over a wavenumber band gives the variance within that band and this variance must be wavenumber-unit independent.
Here are some examples that apply in the inertial subrange.
For the velocity spectrum, we must have

<math> F_{22}(\hat{k}_1) \mathrm{d}\hat{k}_1 = F_{22} (\hat{\kappa}_1)\, \mathrm{d} \hat{\kappa}_1 </math>

and substituting ( ) gives

<math>
\begin{equation}
\begin{split}
\tilde{F}_{22} (\hat{k}_1) \, \mathrm{d}\hat{k}_1 &= \frac{4}{3} C_1 \left(2\pi \hat{k}_1 \right)^{-5/3} \mathrm{d} (2\pi\hat{k}_1 ) \\
&= \left(2\pi\right)^{-2/3}\, \frac{4}{3} C_1 \,\hat{k}_1^{-5/3}\, \mathrm{d}\hat{k}_1
\end{split}
\end{equation}
</math>

which means that, in the inertial subrange, the cross-profile spectrum of velocity, <math>\tilde{F}_{22}(\hat{k}_1)</math>, expressed in units of <math>\mathrm{cpm}</math>, is smaller than the same spectrum, <math>\tilde{F}_{22}(\hat{\kappa}_1)</math>, expressed in units of <math>\mathrm{rad\, m^{-1}}</math>.

Similarly, the universal shear spectrum, using ( ) is

<math>
\begin{equation}
\begin{split}
\tilde{G}_{22} (\hat{k}_1) \, \mathrm{d}\hat{k}_1 &= \frac{4}{3} C_1 \left(2\pi \hat{k}_1 \right)^{1/3} \mathrm{d} (2\pi\hat{k}_1 ) \\
&= \left(2\pi\right)^{4/3}\, \frac{4}{3} C_1 \,\hat{k}_1^{1/3}\, \mathrm{d}\hat{k}_1
\end{split}
\end{equation}
</math>

which means that the shear spectrum, expressed in units of <math>\mathrm{cpm}</math>, is larger by a factor of <math>(2\pi)^{4/3}</math> in the inertial subrange than the shear spectrum expressed in units of <math>\mathrm{rad\, m^{-1}}</math>.
Finally, the complete shear spectrum must integrate to 2/15 over all wavenumbers and, therefore, the peak of the shear spectrum expressed in units of <math>\mathrm{cpm}</math> is larger than the shear spectrum expressed in units of <math>\mathrm{rad\, m^{-1}}</math> by a factor of <math>2\pi</math>.

Spectra of velocity gradients

2021-11-09T22:22:20Z

KikiSchulz:

{{DefineConcept
|description=Often called dissipation spectra, [[Spectra of velocity|velocity spectra]] multiplied by <math>\kappa^2</math> or <math>\kappa_1^2</math>
|article_type=Fundamentals
}}
The spectra of the gradients of velocity are closely related to the rate of dissipation, <math>\varepsilon</math>, and are often called dissipation spectra.
These spectra are the [[Spectra of velocity|velocity spectra]] multiplied by <math>\kappa^2</math> or <math>\kappa_1^2</math>, whichever is appropriate.
The rate of dissipation is related to the gradient of the three-dimensional velocity spectrum by

<math>
\begin{equation}
\begin{split}
\varepsilon &= 2\nu \int_0^{\infty} \kappa^2 E(\kappa)\, \mathrm{d} \kappa = 2\nu \left(\varepsilon\nu^5 \right)^{1/4} \int_0^{\infty} \kappa^2 F(\hat{\kappa})\, \mathrm{d} \kappa \\
&=2\nu \left(\varepsilon\nu^5 \right)^{1/4} L_K^{-3} \int_0^{\infty} \hat{\kappa}^2 F(\hat{\kappa})\, \mathrm{d} \hat{\kappa} \\
&= 2\varepsilon \int_0^{\infty} G(\hat{\kappa})\, \mathrm{d} \hat{\kappa}
\end{split}
\end{equation}
</math>

Thus, the universal (non-dimensional) gradient spectrum is <math>G=\hat{\kappa}^2 F</math> , and its integral over all wavenumbers must equal 1/2.
The along-profile gradient of the along-profile velocity fluctuations often called the rate of strain (or, simply strain), is related to the rate of dissipation by

<math>
\begin{equation}
\begin{split}
\varepsilon &= 15\nu \int_0^{\infty} \kappa_1^2 E_{11}(\kappa_1)\, \mathrm{d}\kappa_1 = 15\nu \left(\varepsilon\nu^5 \right)^{1/4} \int_0^{\infty} \kappa_1^2 F_{11} (\hat{\kappa}_1)\, \mathrm{d} \kappa_1 \\
&= 15\varepsilon \int_0^{\infty} G_{11} (\hat{\kappa}_1)\, \mathrm{d} \hat{\kappa}_1
\end{split}
\end{equation}
</math>

where <math>G_{11}=\hat{\kappa}_1^2 F_{11}</math> is the universal (and non-dimensional) rate of strain spectrum, which must integrate to 1/15.
Similarly, the shear spectrum is related to the rate of dissipation by

<math>
\begin{equation}
\begin{split}
\varepsilon &= \frac{15}{2} \nu \int_0^{\infty} \kappa_1^2 E_{22}(\kappa_1)\, \mathrm{d}\kappa_1 = \frac{15}{2}\nu \left(\varepsilon\nu^5 \right)^{1/4} \int_0^{\infty} \kappa_1^2 F_{22}\, (\hat{\kappa}_1) \mathrm{d} \kappa_1 \\
&= \frac{15}{2}\varepsilon \int_0^{\infty} G_{22} (\hat{\kappa}_1)\, \mathrm{d} \hat{\kappa}_1
\end{split}
\end{equation}
</math>

where <math>G_{22}= \hat{\kappa}_1^2 F_{22}</math> is the universal shear spectrum which must integrate to 2/15.

You want more? Go to [[Spectra in the inertial subrange]]

Spectra of velocity

2021-11-09T22:21:41Z

KikiSchulz:

{{DefineConcept
|description=Theoretically derived spectrum of velocity fluctuations in the inertial subrange.
|article_type=Fundamentals
}}
The spectrum of velocity fluctuations has only been derived theoretically for the inertial subrange.
This is the range of eddy sizes at which the flow is isotropic – they have lost the orientation of the largest eddies – but, their size is still large enough to not be significantly affected by viscosity.
In this range kinetic energy is transferred to smaller scales through inertial interaction of the eddies but no energy is lost through friction.
The three-dimensional spectrum of velocity, in the inertial subrange, is <br>

<math> E(\kappa)=C\varepsilon^{2/3} \kappa^{-5/3} </math>
<br>

where <math>\kappa</math> is the magnitude of the angular wavenumber in units of <math>\mathrm{rad\,m^{-1}}</math> and <math>C\approx1.5</math> is the three-dimensional Kolmogorov constant<ref> Kolmogorov, A. N. (1941). Local turbulence structure in incompressible fluids at very high Reynolds numbers. In Dokl. Akad. Nauk SSSR (Vol. 30, No. 4).</ref>. There is no theoretical derivation for the velocity spectrum at wavenumbers beyond the inertial subrange. It is common to express the entire spectrum by<br>

<math>
E(\kappa)=C\varepsilon^{2/3} \kappa^{-5/3} f_{\eta} \left(\kappa_{L_K}\right)
</math>
<br>

where <math>f_{\eta}</math> characterizes the spectrum in the dissipation range, has a value of unity in the inertial subrange (<math>\kappa L_K \ll 1</math>), and <math>L_K=\left(\nu^3/\varepsilon\right)^{1/4}</math> is the Kolmogorov length.
It is thought that the velocity spectrum can be described by a universal non-dimensional spectrum, <math>F</math>, defined by

<math> E(\kappa) = \left(\varepsilon \nu^5 \right)^{1/4} F(\hat{\kappa})</math>

where <math> \hat{\kappa} =\kappa L_K</math> is the non-dimensional wavenumber.

It is currently not possible to measure the three-dimensional spectrum of velocity.
It is only possible to measure the one-dimensional spectrum of velocity – the spectrum derived from a profile in a single direction.
The one-dimensional spectrum of the component of velocity that is ''parallel'' to the direction of profiling is

<math> E_{11} (\kappa_1 )= \int_{\kappa_1}^{\infty} \frac{E(\kappa)}{\kappa} \left( 1- \frac{\kappa_1^2}{\kappa^2} \right) \, \mathrm{d} \kappa </math>

where <math> \kappa_1</math> is the angular wavenumber in the direction of profiling.
The universal spectrum associated with <math>E_{11} </math> is given by

<math> E_{11} (\kappa_1) = \left( \varepsilon \nu^5 \right)^{1/4} F_{11} (\hat{\kappa}_1) </math>

and, therefore,

<math> F_{11} (\hat{\kappa}_1 )= \int_{\hat{\kappa}_1}^{\infty} \frac{F(\hat{\kappa})}{\hat{\kappa}} \left( 1- \frac{\hat{\kappa}_1^2}{\hat{\kappa}^2} \right) \, \mathrm{d} \hat{\kappa} </math>

Similarly, the one-dimensional spectrum of the component of velocity that is ''orthogonal'' to the direction of profiling is

<math> E_{22} (\kappa_1 ) = \frac{1}{2} \int_{\kappa_1}^{\infty} \frac{E(\kappa)}{\kappa} \left( 1 + \frac{\kappa_1^2}{\kappa^2} \right) \, \mathrm{d} \kappa </math>

and its universal spectrum is defined by

<math> E_{22} (\kappa_1) = \left(\varepsilon\nu^5 \right)^{1/4} F_{22} (\hat{\kappa}_1) </math>

so that

<math> F_{22} (\hat{\kappa}_1) = \frac{1}{2} \int_{\hat{\kappa}_1}^{\infty} \frac{E(\hat{\kappa})}{\hat{\kappa}} \left( 1 + \frac{\hat{\kappa}_1^2}{\hat{\kappa}^2} \right) \, \mathrm{d} \hat{\kappa} </math> .

These two one-dimensional spectra are related to each other by

<math> F_{22} (\hat{\kappa}_1)= \frac{1}{2} \left( F_{11} (\hat{\kappa}_1) - \hat{\kappa}_1 \frac{\mathrm{d}F_{11}(\hat{\kappa}_1)}{\mathrm{d}\hat{\kappa}_1} \right) </math>

and, thus, <math>F_{22}=\frac{4}{3} F_{11}</math> in the inertial subrange.
These relationships hold for any direction of profiling, as long as we refer to the velocity component that is parallel to the direction of profiling by the subscripts (<math>_{11}</math>) and the (mutually orthogonal) pair of velocity components that are orthogonal to the direction of profiling using the subscripts (<math>_{22}</math>).
Thus, the second orthogonal velocity component has the spectrum <math>E_{33}\equiv E_{22}</math> .

You want more? Check out [[Spectra of velocity gradients]]

Spectra in the inertial subrange

2021-11-09T22:19:11Z

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Spectra of velocity gradients

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Spectra of velocity

2021-11-09T22:07:24Z

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2021-11-09T22:03:15Z

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