Calibration settings for Simrad SP70 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 SP70 data files.

We recommend you assess the suitability of the settings available on the Calibration pages for each acoustic 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.

Changes in calibration settings used for range calculations may shift ping data in the depth dimension but will not automatically adjust the position of regions and lines. You should review any existing regions and lines to ensure they are still valid. For more information refer to Range calculation effects on regions and lines.

Note: Data file values that have been used since the data was loaded or the ECS file was added, saved or removed are displayed in black text. Default values that have been used are displayed in orange text. Data file or ECS values that have been read but not used are displayed in grey text. Read About calibration settings for further information.

Sv pings

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 school detection.

The SoundSpeed is used to calculate the data point range.

Echoview uses the  signal magnitudes stored in the data files and the Multibeam magnitudes to Sv algorithm to derive the Sv pings variable. This variable can utilize calibration settings for each beam (MultibeamBeamOffsets) 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:

unspecified dB pings

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 school detection.

The SoundSpeed is used to calculate the data point range.

See also

About calibration settings
Entering calibration settings

Simrad data files
Raw variables derived from Simrad SP70 data