Calibration settings for text data

Single beam variables

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 Text data files.

We recommend you assess the suitability of the settings available on the Calibration pages for each acoustic variable. The settings on the calibration pages for text data are not used to calculate data point values or data point ranges. However, the settings may be used for other purposes which require that you enter correct values. See Additional_uses_of_calibration_settings.

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.

A transducer can be selected to apply transducer geometry to the echogram.

Single beam variables in CSV files

Setting	Sv pings	Single target pings	All acoustic variables
Setting	Data point values		Range
Calibration page of Variable Properties dialog box
Frequency		Y
AbsorptionCoefficient	Y	Y
AbsorptionCoefficientLogging	Y	Y
MajorAxis3dbBeamAngle		Y
PulseDuration		Y
TwoWayBeamAngle		Y
SoundSpeed	Y	Y
SoundSpeedLogging	Y	Y
From data file
Start range			Y
Stop range			Y
Number of data points			Y

Multibeam variables

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 Multibeam text 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.

Note: The (orange) 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.

Multibeam Sv text data

On the Calibration page of the Variable Properties dialog box, 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 for multibeam variables but may be used for single beam variables created from multibeam variables.

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

When specifying per-beam calibration, it is good practice to verify the settings for the correct number of beams.
Prior to Echoview 5 this format used the (deprecated) Echoview ASCII calibration file to specify per-beam calibration values.

All other variables from multibeam text data files

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 for multibeam variables but may be used for single beam variables created from multibeam variables.