Calibration settings for BioSonics data

This page describes the settings, necessary to an Echoview calculation, on the Calibration page of the Variable Properties dialog box for acoustic variables derived from Biosonics data files.

We recommend you assess the suitability of the settings available on the Calibration pages for each acoustic variable. Some settings are used to calculate datapoint values or ranges, others may be used during analysis or display of the data. The table below shows which settings are used for calculating datapoint values and ranges, which are used for other calculations and which settings may not be used by the variable.

Quantitative calculation/analysis requires calibrated data which is achieved using correct calibration setting values (rather than default values). An ECS file enables you to modify calibration settings for variables in a fileset.

Note: The (red) default values on the Calibration pages are for illustration purposes only and have not been read from your data file. Read About calibration settings for further information.

Table legend:

P	Setting is used in calculating datapoint values or ranges as indicated by the column heading.
	Setting is not used in calculating datapoint values (when green background) or ranges (when blue background) but may be used for other purposes, see Additional uses of Calibration settings
	Setting is not available for this variable

Setting	Datapoint values			Datapoint range
Setting	Sv	TS	Angular positions	All acoustic variables
Calibration page of Variable Properties dialog box
AbsorptionCoefficient	P	P
CalibrationOffset	P	P
Dt4PowerSetting	P	P
Frequency
MajorAxis3dBBeamAngle	P
MajorAxisAngleOffset+			P
MinorAxis3dBBeamAngle	P
MinorAxisAngleOffset+			P
SoundSpeed	P		P	P
TransmittedPulseLength	P
TvgRangeCorrection	P	Not used for the TS variable.
TwoWayBeamAngle1
WedgeVolumeBeamAngle
From data file
InitialBanking	P	P		P
SamplePeriod	P	P		P
SamplesPerPing	P	P		P

Notes:

If you know the frequency, temperature and salinity, you can calculate the absorption coefficient calibration settings using the Sonar Calculator. The sound speed and absorption coefficients are calculated using standard formulae. Echoview does not calculate these automatically from the settings in a data file. Choose Show information from the shortcut menu (right-click) to determine the settings that are recorded in a BioSonics data file.
Some BioSonics echosounders are equipped with an option to operate at a reduced power level. Echoview reads the reduced power level from the data file and calculates Sv and TS taking into account the reduced power level.
+ The MajorAxisAngleOffset and MinorAxisAngleOffset are read from the data file but can be overridden with values obtained during a the calibration of an echosounder with a calibration sphere. See also BioSonics data files: Calculation of angles for split beam transducers.
1 TwoWayBeamAngle is calculated using the 3 dB beam angles. Alternatively, a value can be specified using an ECS file which is added to the fileset.

Other required calibration settings are read from the BioSonics data file (EEPROM structure).

Calibration settings for BioSonics data

See also