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 SH80 data files.
We recommend you assess the suitability of the settings available on the Calibration pages for each acoustic variable. Some settings will be used to calculate datapoint values or ranges, others may be used during analysis or display of the data.
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.
A transducer can be selected in order to apply transducer geometry to the echogram. However, note that the 3dB beam angle setting is not used. Schools variables are not corrected for beam width. There is no correction for beam shape in 3D schools detection.
The AbsorptionCoefficient is used in the calculation of the datapoint range.
Echoview uses the the signal magnitudes stored in the data files and the Mulitbeam magnitudes to Sv algorithm to derive the Sv pings variable. This variable can utilize calibration settings for each beam (MultibeamBeamOffests) or apply a value that will be applied to all beams (CalibrationOffset). These settings can be set with an ECS file which must be added to a fileset.
Notes:
No calibration settings apply. A transducer can be selected in order to apply transducer geometry to the echogram. However, note that the 3dB beam angle setting is not used. Schools variables are not corrected for beam width. There is no correction for beam shape in 3D schools detection.
About calibration settings
Entering calibration settings
Simrad data files
Raw variables derived from SH80 data files