Level 3 data (velocity profilers)
| 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.
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?? | along-beam_separation_distance_over_which_DLL_is_evaluated | 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. |
| |
| dll_calculation_type | Specify differencing technique used to estimate DLL | Examples include
| |
| 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
