5 backscatter and snippet processing (geocoder) – Triton Bathymetry User Manual

Page 43

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8.5 Backscatter and Snippet Processing (Geocoder)

For backscatter and snippet processing we utilize Geocoder written by Dr. Luciano
Fonseca, for the Center for Coastal and Ocean Mapping, University of New Hampshire.
Currently Geocoder is a stand-alone application but work is in progress to integrate it into
Perspective. To launch Geocoder, use the toolbar button shown right.

Currently only the following two sonars manufacturers are supported for processing
multibeam imagery data in Geocoder:

Kongsberg/Simrad multibeam (.all) - beam time series and beam average

Reson (.xtf, .s7k) - beam time series and beam average

There are 4 basic steps to processing backscatter or snippet data in Geocoder.

1. Set

Source

menu to “Beam Average”

This will extract the average beam intensity from the lines. OR

Set

Source

menu to “Beam Time Series”

This will extract the beam time series data from the lines.

2. From the

Project

menu, select “Insert Line”

As the lines selected are loaded into Geocoder, navigation for each line is
displayed in the map view. By default the navigation lines are set to display in
the

Show

menu. For data in the southern hemisphere first select the

“Southern Hemisphere” option in the

Edit

menu before inserting lines.

For Kongsberg data, load the original .ALL files

For Reson data, load the GSF files generated when creating a grid. For best
results be sure to perform all 2D/3D editing first to clean the data.

3. In the

Options

and

Mosaic

Menus, verify that the items checked on the images

shown at the top of the following page are selected.

Generally these options give the best results but others may apply depending
on the data being processed.

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