Data processing
The raw sonar and navigation data must be processed before maps can be made
The multibeam processing package MB-System is used extensively for planning the surveys, and for correcting roll and pitch biases, editing the sonar data, and adjusting the navigation data, post-survey.
Planning the survey
| Surveys are planned with MB-System's package "Mbgrdviz". Altitude off the bottom, line spacing, and crossings can all be specified. Missions are typically composed of a sequence of straight lines that connect at waypoints. Missions are downloaded to the vehicle over a radio link before the dive. Waypoints can also be sent to the ship's bridge. |  Plan to "mow the lawn" (survey grid) in Mbgrdviz. Image © MBARI 2005 |
Roll and pitch bias correction
The vehicle's roll and pitch are logged and can be accounted for in post-processing.
Editing sonar data
| Sonar data are edited with MB-System's package "mbedit". All the beams within each ping of the swath are displayed for editing. Bad beams can be flagged so that they will not be considered during further processing. |
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Navigation adjustment
Programmed into the deployment's track are several crossings so that drift during the dive can be corrected later. MB-System's utility "Mbnavadjust" is used to match features in overlapping swaths and adjust the navigation. >> More about the vehicle navigation |
 Screen grabs of Mbnavadjust showing procedure to obtain best fit of overlapping swaths. Image © MBARI 2005 |
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