Level 3 data (shear probes): Difference between revisions

From Atomix
← Older editNewer edit →
VisualWikitext
No edit summary
No edit summary
Line 37: Line 37:
! Parameter Name !! Standard Name !! Units of measurement !! dimension  
! Parameter Name !! Standard Name !! Units of measurement !! dimension  
|-
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^b</math> || TIME_SPECTRA  
| 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
| SECTION_NUMBER || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
Line 47: Line 47:
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, N_WAVENUMBER]   
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, N_WAVENUMBER]   
|-
|-
| DOF || degrees_of_freedom_of_spectrum || - || 1 
| 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_VIB_SENSORS || number_of_vibration_sensors_used_for_cleaning_spectra || - || N_GLOBAL_VALUES
|-
|-
| SH_SPEC_CLEAN<math>^a</math>|| shear_probe_spectrum_clean || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
| SPEC_STD || standard_deviation_uncertainty_of_shear_spectrum || - || N_GLOBAL_VALUES
|}
|}
<math>^a</math> SH_SPEC_CLEAN must be included in the file  if these spectra were used to compute <math>\varepsilon</math>
<math>^a</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
 
<math>^b</math> SH_SPEC_CLEAN must be included in the file  if these spectra were used to compute <math>\varepsilon</math>
 


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


Line 72: Line 78:
|-
|-
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC]  
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC]  
|-
| DOF || degrees_of_freedom_of_spectrum || - || 1 
|}
|}
</div>
</div>

Revision as of 07:21, 21 September 2023

Level 3 data contains the raw (and optionally cleaned) 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 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 meta data.


Dimensions


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]\displaystyle{ ^a }[/math] dimension for 1 data point (for the entire analysis)

[math]\displaystyle{ ^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.


Required Variables


Parameter Name Standard Name Units of measurement dimension
TIME time CF-Conventions compatible offset[math]\displaystyle{ ^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]\displaystyle{ ^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_VIB_SENSORS number_of_vibration_sensors_used_for_cleaning_spectra - N_GLOBAL_VALUES
SPEC_STD standard_deviation_uncertainty_of_shear_spectrum - N_GLOBAL_VALUES

[math]\displaystyle{ ^a }[/math] i.e. "Days since YYYY-MM-DDT00:00:00Z"

[math]\displaystyle{ ^b }[/math] SH_SPEC_CLEAN must be included in the file if these spectra were used to compute [math]\displaystyle{ \varepsilon }[/math]


Optional Level 3 Variables


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 - 1

Return Dataset requirements for shear probes
go to previous: Level 2 data
go to next: Level 4 data.

Retrieved from "http://atomix.app.uib.no/index.php?title=Level_3_data_(shear_probes)&oldid=4556"