Level 1 data (velocity point-measurements)

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


Dimensions

The number of velocity instruments [N_VEL_INSTRUMENT] is here for completeness, but the benchmarks examples will have measurements only from one instrument stored.

Short name Standard name Dimensions Comments
TIME time time Units in Days since 1950-01-01T00:00:00Z
TIME_HPR time_of_heading_pitch_roll TIME_HPR Heading, pitch and roll (tilt) sensors measure always at 1Hz for Vector ADV
N_VEL_COMPONENT number_of_velocity_component N_VEL_COMPONENT Maximum of 3 for u,v, w (east,north, up) velocities
N_VEL_INSTRUMENT number_of_unique_velocity_instruments N_VEL_INSTRUMENT Required only if storing multiple synchronized instruments in the same file

Variables

Required variables

Short name Standard name Dimensions Comments
ABSIC backscatter_intensity_from_acoustic_beam TIME, N_VEL_COMPONENT, N_VEL_INSTRUMENT
CORRN noise_correlation_percent_from_each_acoustic_beam TIME, N_VEL_COMPONENT, N_VEL_INSTRUMENT
[math]\displaystyle{ \ddagger }[/math] XYZ_VEL (or ENU_VEL/BEAM_VEL) TIME, N_VEL_COMPONENT, N_VEL_INSTRUMENT
[math]\displaystyle{ \dagger }[/math] HEIGHT or DEPTH TIME, N_VEL_INSTRUMENT
HEADING TIME_HPR, N_VEL_INSTRUMENT
PITCH TIME_HPR, N_VEL_INSTRUMENT
ROLL TIME_HPR, N_VEL_INSTRUMENT
[math]\displaystyle{ \ddagger }[/math] Some manufacturers record quality-control variables (e.g., CORRN) in the instrument coordinate system. For example, Nortek records these variables in the instrument XYZ frame of reference. It's best to record the data in that coordinate system.

[math]\displaystyle{ \dagger }[/math] A variable situating the instruments in the water column is required. This may be a nominal depth (or height) or a time-varying depth or height above the bottom.

Required height variable

Height or depth-related variables (only 1x is required). These variables locate the instrument vertically from a boundary (e.g, surface or ice). A negative value implies it's below the boundary. Units are always in meters.

Short name Standard name Dimensions
HEIGHT_AB height_above_bottom TIME, N_VEL_INSTRUMENT
DEPTH depth_below_surface TIME, N_VEL_INSTRUMENT

Optional variables

Short name Standard name Dimensions
PRES TIME, N_VEL_INSTRUMENT
SNR TIME, N_VEL_COMPONENT
TEMP, and other scalars* TIME
*Data from concurrent sensors may be optionally included e.g., temperature, dissolved oxygen (e.g., eddy-correlation system)



Group attributes (metadata)

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

Required metadata

  • processing_level: This group includes the raw measurements from the recorder, and ancillary measurements required for quality-controlling them using the manufacturer's recommendations.
  • Att2
Attribute name Purpose Suggested content
processing_level Boilerplate comment about the ATOMIX Level 1 content.

This group includes the raw measurements from the recorder and ancillary measurements required for quality-controlling them using the manufacturer's recommendations.

Optional metadata

  • Enter here
Retrieved from "http://atomix.app.uib.no/index.php?title=Level_1_data_(velocity_point-measurements)&oldid=3180"