Level 3 data (velocity profilers): Difference between revisions

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=Dimensions=
=Dimensions=


{| class="wikitable sortable"
|-
! Short name
! Standard name
! Dimensions
! Comments
|-
| TIME
| time
| TIME
| Units in Days since 1950-01-01T00:00:00Z
|-
| N_BEAM
| unique_identifier_for_each_beam
| N_BEAM
| Array of 1 to number of beams (4 or 5 typically)
|-
| R_DIST
| distance_from_sensor_along_beams
| R_DIST
| Along-beam bin centre distance (in meters) from the transducer
|-
| R_DEL??
| ??
| R_DEL (variable?)
|
|-
| colspan="4" style="text-align:center; font-weight:bold; background-color:#f9eddd"|  Optional dimensions for 5-beam ADCP <math>\ddagger</math>
|-
| R_DIST5
| distance_from_sensor_along_beam_5
| R_DIST5
| Along-beam bin centre distance (in meters) from the transducer for the 5th vertical beam
|}
</div>
=Variables=
<div class="mw-collapsible" id="raw" data-collapsetext="Collapse" data-expandtext="Expand variables">
<br>
{| class="wikitable"
|-
! Short name
! Standard name
! Dimensions
! Comment
|-
| DLL
| water_radial_velocity_of_scatterers_toward_instrument_in_each_beam
| TIME,  R_DIST, R_DEL, N_BEAM
|
|-
| N_SEGMENT
| unique_identifier_for_each_
segment_in_the_entire_available_timeseries
| TIME
| Enables backtracking to [[Level 2 segmented (velocity profilers)|previous processing level]]
|-
| BURST_NUMBER <math>\dagger\dagger</math>
| unique_identifier_for_each_burst
| TIME
| Only required when measuring in burst-mode. Integers of 1, 2, etc to designate which burst the velocities are associated with.
|-
| colspan="4" style="text-align:center; font-weight:bold; background-color:#f9eddd"|  Optional dimensions for 5-beam ADCP <math>\ddagger</math>
|-
| DLL5
| water_radial_velocity_of_scatterers_toward_instrument_in_beam_5
| TiME, R_DEL5, R_DIST5
| Only necessary for 5-beam ADCP
|-
| colspan="4" |
<math>\dagger\dagger</math> Variable required only when measuring in bursts e.g., 18 min of continuous measurements every hour.
|}
</div>
=Group attributes (metadata)=
<div class="mw-collapsible"  id="raw_att" data-expandtext="Expand group attributes" data-collapsetext="Collapse attributes">
This section describes attributes that may provide additional information about how the data was processed and manipulated at this stage.
{| class="wikitable"
|-
! Attribute name
! Purpose
! Suggested content
|-
| processing_level
| Boilerplate about the content of the NetCDF group.
| <blockquote>''This group includes the structure function Dll as a function of the separation distance.  Any ancillary information required for estimatng the dissipation of turbulent kinetic energy may also be stored here. ''</blockquote>
|-
| dll_calculation_type
| Specify differencing technique used to estimate DLL
| Examples include
<blockquote>Central-differencing</blockquote>
    <blockquote>Forward-differencing</blockquote>
|-
| colspan="4" style="text-align:center; font-weight:bold; background-color:#f9eddd"|  Optional group attributes <math>\ddagger</math>
|-
| stationarity_testing
| Any testing done on the segment to verify stationarity?
|
|-
| noise_testing
| Details of testing the noise levels, or if the signal comprises mostly of noise?
|
|-
| comment (optional)
| Any additional information pertinent to other users who test their algorithms against the file.
|
|}
</div>


----
----
Return to [[Level 2 data (velocity profilers)| Level 2 quality-controlled and segmented velocities]]
Return to [[Level 2 data (velocity profilers)| Level 2 quality controlled and segmented velocities]]
 
Go to [[Level 4 data (velocity profilers)| Level 4 dissipation estimates]]
Go to [[Level 4 data (velocity profilers)| Level 4 dissipation]]

Revision as of 13:08, 16 December 2021

Page status: Draft
Author(s): Cynthia
Reviewer(s):
Comment:


The required dimensions and variables for the structure-function processing level within NetCDF ATOMIX format for velocity ADCP measurements are described below. This NetCDF group contains the structure function (DLL) calculated as a function of the along-beam separation for the available/usable ADCP bins.



Schematic of ADCP processing nomenclature

Dimensions

Short name Standard name Dimensions Comments
TIME time TIME Units in Days since 1950-01-01T00:00:00Z
N_BEAM unique_identifier_for_each_beam N_BEAM Array of 1 to number of beams (4 or 5 typically)
R_DIST distance_from_sensor_along_beams R_DIST Along-beam bin centre distance (in meters) from the transducer
R_DEL?? ?? R_DEL (variable?)
Optional dimensions for 5-beam ADCP [math]\displaystyle{ \ddagger }[/math]
R_DIST5 distance_from_sensor_along_beam_5 R_DIST5 Along-beam bin centre distance (in meters) from the transducer for the 5th vertical beam


Variables


Short name Standard name Dimensions Comment
DLL water_radial_velocity_of_scatterers_toward_instrument_in_each_beam TIME, R_DIST, R_DEL, N_BEAM
N_SEGMENT unique_identifier_for_each_

segment_in_the_entire_available_timeseries

TIME Enables backtracking to previous processing level
BURST_NUMBER [math]\displaystyle{ \dagger\dagger }[/math] unique_identifier_for_each_burst TIME Only required when measuring in burst-mode. Integers of 1, 2, etc to designate which burst the velocities are associated with.
Optional dimensions for 5-beam ADCP [math]\displaystyle{ \ddagger }[/math]
DLL5 water_radial_velocity_of_scatterers_toward_instrument_in_beam_5 TiME, R_DEL5, R_DIST5 Only necessary for 5-beam ADCP

[math]\displaystyle{ \dagger\dagger }[/math] Variable required only when measuring in bursts e.g., 18 min of continuous measurements every hour.

Group attributes (metadata)

This section describes attributes that may provide additional information about how the data was processed and manipulated at this stage.


Attribute name Purpose Suggested content
processing_level Boilerplate about the content of the NetCDF group.

This group includes the structure function Dll as a function of the separation distance. Any ancillary information required for estimatng the dissipation of turbulent kinetic energy may also be stored here.

dll_calculation_type Specify differencing technique used to estimate DLL Examples include

Central-differencing

Forward-differencing

Optional group attributes [math]\displaystyle{ \ddagger }[/math]
stationarity_testing Any testing done on the segment to verify stationarity?
noise_testing Details of testing the noise levels, or if the signal comprises mostly of noise?
comment (optional) Any additional information pertinent to other users who test their algorithms against the file.

Return to Level 2 quality controlled and segmented velocities Go to Level 4 dissipation estimates

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