USGS MIPS Avgbrt Documentation

USGS MIPS Avgbrt Documentation

This program is used to correct shading problems between the left and right halves of sidescan sonar images . That is, the left side may be brighter than the right side because of gain differences when the sides were collected.

An automatic correction is done by first calculating the averages of the left and right sides, and then adding the difference of the averages to the side with the lesser average. A manual correction can be done by adding a user specified offset to a user specified side (left or right).

Files

This program requires as input one unsigned 8-bit or one signed labels
Mosaic labels
Projection labels
Sonar labels
Navigation file
History file

Parameters

SL and EL: These parameters define the sub-area to be used to calculate left and right side averages. They default to include the entire sidescan sonar image. These parameters can be used to select a sub-area of the sidescan sonar image which is relatively featureless so that the averages are not affected by the features in the data.
LEFT and RIGHT: These parameters can be used to add an offset to the left or right side of the sidescan sonar image. If a value for LEFT or RIGHT is entered the program does not compute the averages but instead adds the offset to each dn on the indicated side of the sidescan sonar image.

Examples

Sonar image with gain differences on left and right sides.

[Example Image]

Image corrected using the program AVGBRT.

[Example Image]