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- time: vector, timestamp in datenum format (obtained from time the reading reached the shore station)
- range: vector of distance to each bin centre. If bin mapping compensation for tilt is active, this is then a vertical range to the bin centres, see data.processingComments to see if bin mapping was applied. (Prior to Feb 26, 2015: vector of distance to start of each bin)
- cellDepth: vector, starting depth of each cell calculated from range and deployment depth (may be inaccurate if instrument is vertically mobile)
- u,v,w: 2D matrices, East/North/Up velocities relative to True North, derived using raw velocity matrix, orientation, coordinate system, transformation matrix and one of a) calculated magnetic declination based on time and location (for mobile adcps) or b) meta.deviceHeading (fixed position ADCPs)
- u_std, v_std, w_std: standard deviations for ensemble averaged u,v,w (averaged products only).
- pingsPerEnsemble: vector, number of pings that contributed to the ensemble (averaged products only).
- velocity: 3D matrix, corresponds directly to output of instrument and so depends on configuration coordinate system
- amplitude: 3D matrix, amplitude time-series for each of the three receivers. From Nortek Technical Note No. 3: " All Nortek systems use the same component family to measure the amplitude for the echo. This component outputs a signal that is referred to as the RSSI and that is proportional to logarithm of the echo strength. The dynamic range of this signal is about 90 dB and it is linear within an accuracy of about 1-2 dB over a range of 70 dB. Inside this range, the scaling factor is about 0.45 counts/dB but with some variation (about 0.40 to 0.47)."
- correlation: 3D matrix, signal correlation coefficient time-series for each of the three receivers (only available for HR-Profilers)
- compassHeading: vector, magnetic compass heading time-series. (Strictly from onboard sensor. See data.processingComments to determine which source was used for rotation: one of internal or external sensor or fixed value.)
- pitch: vector, pitch time-series. (Strictly from onboard sensor. See data.processingComments to determine which source was used for rotation: one of internal or external sensor or fixed value.)
- roll: vector, roll time-series. (Strictly from onboard sensor. See data.processingComments to determine which source was used for rotation: one of internal or external sensor or fixed value.)
- pressure: vector, pressure time-series
- temperature: vector, temperature time-series
- soundSpeed: vector, sound speed time-series (often constant, depending on configuration)
- voltage: vector, battery voltage time-series
- error: vector, error code (see the manufacturer's system integrator guides to decode)
- backscatter: 3D matrix based on received signal strength intensity (adcp.intensity), compensated for two-way spreading (20LogR) and absorption. Equation based on Gostiaux and van Haren ("Extracting Meaningful Information from Uncalibrated Backscattered Echo Intensity Data, Journal of Atomsheric Atmospheric and Oceanic Technology, 72, 943-949, 2010). The absorption computation follows Ainslie and Malcolm ("A simplified formula for viscous and chemical absorption in sea water", Journal of the Acoustical Society of America, 103(3), 1671-1672, 1998). Absorption coefficient is based on mean depth, temperature and salinity in adcp structure.
- meanBackscatter: same as above, except averaged over the four beams to create a 2D matrix. Averaging is done by converting to standard intensity, averaging, then converting back to decibels.
- processingComments: cell array char field of comments, documenting all of the processing steps taken on the data (such as transform from beam co-ordinates to East-North-Up) and the sources of positioning data applied (heading, pitch, roll, depth)
- magneticDeclination: value that can be applied to correct the compassHeading to true North.
- corScreenThresholdUsed: value used for the correlation screen, i.e. data with correlation less than this are screened (replaced with NaN) from the final u,v,w velocities.
- amplitudeVerticalRange: tilt-corrected range for plotting backscatter (calculated as cos( average tilt ) * range).
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