Raw data formats such as XTF contain two-way travel time and beam launch angle data. The Sound Velocity Correction algorithm uses this data to calculate the length and path of the sound wave through the water column for each beam.
Sound velocity processing is not available for all types of multibeam and single beam sonar data. Some of the supported sonars are from Atlas, EdgeTech, EIVA, Elac, Imagenex, Klein, Kongsberg GeoAcoustics, Kongsberg Maritime, SEA SWATHplus, Teledyne Odom and Teledyne Reson.
Only those sonar formats that provide raw travel time and angle from the transducer are currently supported in HIPS.
Supported formats for multibeam/interferometric/SAS bathymetry include:
• ALL | • D1P | • GSF | • JSF |
• HSX | • PDS | • RDF | • S7K |
• SBD | • SDF | • SURF | • SXR |
• TDY | • XSE | • XTF |
For other types of multibeam sonar formats, it is assumed that sound velocity corrections were applied during data acquisition.
HVF
For effective sound velocity correction, the Sound Velocity section of the HIPS Vessel file must be set up to define the transducer offsets. These offsets are used in Sound Velocity Correction, together with the Sound Velocity profile data.
SVP file
A sound velocity profile contains data on the acoustic velocity of the water column, in a text file divided into sections defined by time stamps. This data can be viewed and modified in the SVP Editor (see SVP Files).
The process of Sound Velocity Correction cannot be reversed. Once it is applied, data cannot be restored to its pre-SVC state. |