Show calibration gain adjustments
This procedure is used to display the gain adjustment being calculated for each beam
Prerequisites
A calibration must have been completed and stored.
Context
The calibration procedure will result in adjusting a set of coefficients. These coefficients are in turn used when processing target strength data in order to get a correct and as optimum result from surveys as possible. The gain adjustments is calculated for each beam in the swath. By using the Beam Directions Plot you will see gain adjustments in a colour representation which makes it easier to locate beams where the gain adjustment has been significantly different from the other beams. These will have a deviant colour. The gain adjustment is also displayed in the Numerical View information field in the Results tab. This is a purely numerical display. Such erroneous results may occur due to disturbances during calibration such as jellyfish, fish or other and will in turn affect the target strength calculations in surveys.
Procedure
1 Select Beam Mode.
a Open the Setup menu.
b Select Beam Mode Adm.
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Selecting Beam Mode Adm opens the Beam Mode Administration dialog box in edit mode. In edit mode you will be able to edit, create and delete beam modes.
c Select the beam mode you wish to use for the calibration.
The Beam Modes page lists the beam modes that have been created. You can select any beam mode from the list. The Mode Description page displays a short description of the beam mode.
2 Select Edit.
This opens the Beam Mode dialog box for the appropriate beam mode. In edit mode you will be able to edit, create and delete beam modes.
3 Open the Calibration page.
The Calibration page displays all calibration data sets made and a short description of them.
a Select the calibration data set to display.
b Select Apply.
4 Select Show calibration gain adjust.
This opens the Beam Direction Plot page in the Beam Mode dialog box.
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The Beam Direction Plot displays all the gain adjustments (in dB) that have been made to all the beams. The colour of the beam represents the calculated adjustment. The colour scale is shown at the bottom of the page.