Edit ReviewStage: Level 1 data (velocity profilers)

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 Velocity point-measurements  Velocity profilers  Shear probes

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The required dimensions and variables for the first processing level within NetCDF ATOMIX format for ADCP velocity measurements are described below. This processing level contains the raw measurements recorded by the instrument. If sampling is in [[Burst sampling|burst mode]], the measurements from individual [[Burst sampling|bursts]] are appended together. Only a few attributes for each variable are listed since the page's purpose is to describe the information layout within each NetCDF file. Please refer to the {{FontColor|bg=#fca1fd|text= [[NetCDF_parameter|complete list]]}} for the additional attributes related to each variable (e.g., units, bounds, cell_methods). =Dimensions= <div class="mw-collapsible" id="raw" data-collapsetext="Collapse" data-expandtext="Expand dimensions"> <br> {| class="wikitable sortable" |- ! Short name ! Standard name ! Dimensions ! Comments |- | TIME | time | TIME | Units in Days since reference time specified in variable attribute |- | Z_DIST | distance_from_sensor_along_vertical | Z_DIST | bin centre distance (in meters) from the transducer along the instrument's vertical axis |- | N_BEAM | unique_identifier_for_each_beam | N_BEAM | Array of 1 to number of beams (3 to 5 typically) |} </div> =Variables= <div class="mw-collapsible" id="raw" data-collapsetext="Collapse" data-expandtext="Expand variables"> <br> ==Required variables== {| class="wikitable" |- ! Short name ! Standard name ! Dimensions ! Comments and units |- | R_VEL | water_radial_velocity_of_scatterers_ towards_instrument. | TIME, Z_DIST, N_BEAM | Units in m/s. Corresponds to <math> b </math> in [[Nomenclature]] |- | R_VEL_FLAGS | water_radial_velocity_of_scatterers_ towards_instrument_status_flag | TIME, Z_DIST, N_BEAM | Boolean flags (8 bit, 0-255) to represent one of 8 possible reasons for rejection. {{FontColor|fg=white|bg=red|text= Link to own flagging page}} |- | THETA | beam_angle_from_instrument_z_axis | N_BEAM | Units in degrees, positive (usually ~20-30<math>^\circ</math>) |- | BIN_SIZE | instrument_measurement_volume_bin_size | N_BEAM | vertical size of the ADCP bins. Usually the same for all 4 beams, but 5th beam can vary. |- | colspan="4" style="text-align:center; font-weight:bold; background-color:#f9eddd" | '''Quality-control variables recorded by acoustic-Doppler instruments''' <math>\ddagger</math> |- | ABSIC | backscatter_intensity | TIME, Z_DIST, N_BEAM | Units of counts |- | CORR | correlation_magnitude_from_each_acoustic_beam | TIME, Z_DIST, N_BEAM | Unit of counts |- | colspan="4" style="text-align:center; font-weight:bold; background-color:#f9eddd" | '''Platform motion variables''' <math>\dagger</math> |- | HEADING | platform_yaw_angle | TIME | degrees, clockwise from true North |- | PITCH | platform_pitch_angle | TIME | degrees |- | ROLL | platform_roll_angle | TIME | degrees |- | colspan="4" style="text-align:center; font-weight:bold; background-color:#f9eddd" | '''Optional variables''' <math>\dagger\dagger</math> |- | BURST_NUMBER | unique_identifier_for_each_burst | TIME | Integers of 1, 2, etc to designate which [[Burst sampling|burst]] the velocities are associated with. Only required when measuring in burst-mode. |- | PROFILE_NUMBER | unique_identifier_for_each_profile | TIME | This variable identifies each record (velocity) profile |- | colspan="4" | <math>\ddagger</math> Quality-control variable names are consistent for those onboard RDI Teleydyne ADCPs. Nortek has CORRN (noise correlation as a % instead of counts) detailed in the [[Level_1_data_(velocity_point-measurements)#Variables|ADV Level 1 variables]]. <math>\dagger</math> Motion variables are necessary for structure function analysis for situating the bins relative the vertical (gravity). These variables do enable converting measurements into geographical. <math>\dagger\dagger</math> BURST_NUMBER is only required when measuring in bursts e.g., 18 min of continuous measurements every hour. Can omit if continuously sampled. PROFILE_NUMBER is essentially an integer proxy for TIME. |} ==Optional ancillary variables== {| class="wikitable sortable" |- ! Short name ! Standard name ! Dimensions ! Comments |- | PRES | sea_water_pressure | TIME | dbar, equals 0 at the sea surface and positive down. |- | TEMP* | sea_water_temperature | TIME | degrees_Celsius, in-situ temperature ITS-90 scale |- | colspan="4" | *Data from concurrent sensors may be optionally included e.g., salinity, dissolved oxygen. Kinematic viscosity of seawater needs to be calculated during processing, |} </div> =Group attributes (metadata)= <div class="mw-collapsible" id="raw_att" data-expandtext="Expand group attributes" data-collapsetext="Collapse attributes"> <br> 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 ATOMIX Level 1 content. | <blockquote>''This group includes the raw measurements from the recorder and ancillary measurements required for quality-controlling them using the manufacturer's recommendations.''</blockquote> |- | comment (optional) | Information is pertinent to problems in the raw data files during collection. | Examples: Stitching of files, corruption of binary files that were recovered by the manufacturer, etc. |} </div> ---- Return to [[Dataset requirements for ADCP structure function]] Go to [[Level 2 data (velocity profilers)| Level 2 segmented]]

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