| EM datagrams on *.kmall format Reg.no. 410224 rev B

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Data Fields
EMdgmMRZ_sounding_def Struct Reference

#MRZ - Data for each sounding, e.g. XYZ, reflectivity, two way travel time etc. More...

`#include <EMdgmFormat.h>`

## Data Fields
uint16_t | soundingIndex
uint8_t | txSectorNumb
Detection info.
uint8_t | detectionType
uint8_t | detectionMethod
uint8_t | rejectionInfo1
uint8_t | rejectionInfo2
uint8_t | postProcessingInfo
uint8_t | detectionClass
uint8_t | detectionConfidenceLevel
uint16_t | padding
float | rangeFactor
float | qualityFactor
float | detectionUncertaintyVer_m
float | detectionUncertaintyHor_m
float | detectionWindowLength_sec
float | echoLength_sec
Water column paramters.
uint16_t | WCBeamNumb
uint16_t | WCrange_samples
float | WCNomBeamAngleAcross_deg
Reflectivity data (backscatter (BS) data).
float | meanAbsCoeff_dBPerkm
float | reflectivity1_dB
float | reflectivity2_dB
float | receiverSensitivityApplied_dB
float | sourceLevelApplied_dB
float | BScalibration_dB
float | TVG_dB
Range and angle data.
float | beamAngleReRx_deg
float | beamAngleCorrection_deg
float | twoWayTravelTime_sec
float | twoWayTravelTimeCorrection_sec
Georeferenced depth points.
float | deltaLatitude_deg
float | deltaLongitude_deg
float | z_reRefPoint_m
float | y_reRefPoint_m
float | x_reRefPoint_m
float | beamIncAngleAdj_deg
uint16_t | realTimeCleanInfo
Seabed image.
uint16_t | SIstartRange_samples
uint16_t | SIcentreSample
uint16_t | SInumSamples

## Detailed Description

#MRZ - Data for each sounding, e.g. XYZ, reflectivity, two way travel time etc.

Also contains information necessary to read seabed image following this datablock (number of samples in SI etc.). To be entered in loop (numSoundingsMaxMain + numExtraDetections) times.

## Field Documentation

uint16_t soundingIndex

Sounding index. Cross reference for seabed image. Valid range: 0 to (numSoundingsMaxMain+numExtraDetections)-1, i.e. 0 - (Nrx+Nd)-1.

uint8_t txSectorNumb

Transmitting sector number. Valid range: 0-(Ntx-1), where Ntx is numTxSectors.

uint8_t detectionType

Bottom detection type. Normal bottom detection, extra detection, or rejected.
0 = normal detection
1 = extra detection
2 = rejected detection In case 2, the estimated range has been used to fill in amplitude samples in the seabed image datagram.

uint8_t detectionMethod

Method for determining bottom detection, e.g. amplitude or phase.
0 = no valid detection
1 = amplitude detection
2 = phase detection
3-15 for future use.

uint8_t rejectionInfo1

For Kongsberg use.

uint8_t rejectionInfo2

For Kongsberg use.

uint8_t postProcessingInfo

For Kongsberg use.

uint8_t detectionClass

Detection class based on detected range.

uint8_t detectionConfidenceLevel

Detection confidence level.

uint16_t padding

Byte alignment.

float rangeFactor

Unit %. rangeFactor = 100 if main detection.

float qualityFactor

Estimated standard deviation as % of the detected depth. Quality Factor (QF) is calculated from IFREMER Quality Factor (IFQ):
QF=Est(dz)/z=100*10^-IQF

float detectionUncertaintyVer_m

Vertical uncertainty, based on quality factor (QF, qualityFactor).

float detectionUncertaintyHor_m

Horizontal uncertainty, based on quality factor (QF, qualityFactor).

float detectionWindowLength_sec

Detection window length. Unit second. Sample data range used in final detection.

float echoLength_sec

Measured echo length. Unit second.

uint16_t WCBeamNumb

Water column beam number. Info for plotting soundings together with water column data.

uint16_t WCrange_samples

Water column range. Range of bottom detection, in samples.

float WCNomBeamAngleAcross_deg

Water column nominal beam angle across. Re vertical.

float meanAbsCoeff_dBPerkm

Mean absorption coefficient, alfa. Used for TVG calculations. Value as used. Unit dB/km.

float reflectivity1_dB

Beam intensity (BS), using TVG = X log(R) + 2 alpha R. X (operator selected) is common to all beams in datagram. Alpha (variabel meanAbsCoeff_dBPerkm) is given for each beam (current struct).
BS = EL – SL – M + TVG + BScorr,
where EL= detected echo level (not recorded in datagram), and the rest of the parameters are found below.

float reflectivity2_dB

Beam intensity, using the traditional KM special TVG.

float receiverSensitivityApplied_dB

Receiver sensitivity (M), in dB, compensated for RX beampattern at actual transmit frequency at current vessel attitude.

float sourceLevelApplied_dB

Source level (SL) applied (dB):
SL = SLnom + SLcorr
where SLnom = Nominal maximum SL, recorded per TX sector (variabel txNominalSourceLevel_dB in struct EMdgmMRZ_txSectorInfo_def) and
SLcorr = SL correction relative to nominal TX power based on measured high voltage power level and any use of digital power control.
SL is corrected for TX beampattern along and across at actual transmit frequency at current vessel attitude.

float BScalibration_dB

Backscatter (BScorr) calibration offset applied (default = 0 dB).

float TVG_dB

Time Varying Gain (TVG) used when correcting reflectivity.

float beamAngleReRx_deg

Angle relative to the RX transducer array, except for ME70, where the angles are relative to the horizontal plane.

float beamAngleCorrection_deg

Applied beam pointing angle correction.

float twoWayTravelTime_sec

Two way travel time (also called range). Unit second.

float twoWayTravelTimeCorrection_sec

Applied two way travel time correction. Unit second.

float deltaLatitude_deg

Distance from vessel reference point at time of first tx pulse in ping, to depth point. Measured in the surface coordinate system (SCS), see Coordinate systems for definition.
Unit decimal degrees.

float deltaLongitude_deg

Distance from vessel reference point at time of first tx pulse in ping, to depth point. Measured in the surface coordinate system (SCS), see Coordinate systems for definition.
Unit decimal degree.

float z_reRefPoint_m

Vertical distance z. Distance from vessel reference point at time of first tx pulse in ping, to depth point. Measured in the surface coordinate system (SCS), see Coordinate systems for definition.

float y_reRefPoint_m

Horizontal distance y. Distance from vessel reference point at time of first tx pulse in ping, to depth point. Measured in the surface coordinate system (SCS), see Coordinate systems for definition.

float x_reRefPoint_m

Horizontal distance x. Distance from vessel reference point at time of first tx pulse in ping, to depth point. Measured in the surface coordinate system (SCS), see Coordinate systems for definition.

float beamIncAngleAdj_deg

Beam incidence angle adjustment (IBA) unit degree.

uint16_t realTimeCleanInfo

For future use.

uint16_t SIstartRange_samples

Seabed image start range, in sample number from transducer. Valid only for the current beam.

uint16_t SIcentreSample

Seabed image. Number of the centre seabed image sample for the current beam.

uint16_t SInumSamples

Seabed image. Number of range samples from the current beam, used to form the seabed image.

The documentation for this struct was generated from the following file:

- EMdgmFormat.h