For systems which employ a flat transducer design, it is critical for the beam-forming electronics to know the exact sound speed at the location of the transducer. Therefore a sound speed probe is installed at the transducer. When this surface sound speed data is available, HIPS converts it and stores the time series data in the SSP file (in the line directory). This data can be displayed in the Attitude Editor.
When HIPS performs sound velocity correction, the SSP data, if available, is retrieved and “inserted” into the Sound Velocity Profile (SVP) at the location of the transducer depth, replacing the interpolated sound speed value at that depth. Ray-tracing then starts from that location
If Surface Sound Speed is available it is applied automatically when using the Sound Velocity Correction (Kongsberg) command. |
Steered Beam Angle
There are times, however, when the SSP data is not correct, causing the beam-forming electronics to erroneously compute beam angle data. If you determine that this has happened, you can enable the option to recompute steered beam angles.
The recorded SSP (known to be incorrect) along with the sound speed interpolated from SVP (assumed to be correct), will be used to compute new beam angle data. Ray-tracing will then proceed without insertion of the SSP into the SVP.
Only certain systems support the re-computation of the steered beam angles. These include:
• Atlas SURF
• Benthos C3D
• GeoAcoustics RDF
• Kongsberg EM 12/120/2040/3000-3008/3020/300/710/122/302
• SWATHplus
• Teledyne Reson 7K (when using the 7004/7006 depth records)