GeoSwath Module

  • Gavia
Gavia Geoswath Module Image
Gavia Geoswath Module Image

Key Features:

  • 1000m rated
  • Very wide swaths even at low altitudes
  • Simultaneous co-registered bathymetry and side scan
  • PPS timing synchronisation
  • Raw data format that can be processed in many third party packages

​The GeoSwath Plus Sonar Module contains a wide-swath bathymetric sonar suitable for a range of survey and inspection tasks. The GeoSwath Plus is a 500kHz interferometric sonar, or phase detecting bathymetric sonar (PDBS) from Kongsberg GeoAcoustics. Boat-mounted GeoSwath sonars are used worldwide for high accuracy surveys including port and harbour navigation and environmental mapping: the Gavia’s GeoSwath module makes this capability available in a commercial AUV. The GeoSwath Plus offers: wide swath coverage of up to 12 times the AUV altitude when near the seabed; integrated bathymetry with simultaneous true digital side scan; high depth resolution suitable for IHO survey standards; as well as the accuracy and repeatability of a boat-mount hydrographic survey system. Like most of the survey-grade sensors on the Gavia AUV, the GeoSwath data is time-synchronised with the AUV master clock using the vehicle PPS/ZDA system. Benefits of the GeoSwath AUV module include ease of deployment, ease of use, reducing survey time, and the ability to take a 500kHz high-resolution sonar down to targets in 1000m of water. The GeoSwath Plus post-processing software (provided as standard with the system) allows a user to inspect and process the data, create and inspect digital terrain models, and create basic sonar mosaics. Several other commercial post-processing software packages are also available, please ask for details. Note that for best results the GeoSwath Module should be deployed with a direct-reading sound velocity sensor (option) in the Control Module, and one of the high-accuracy INS/DVL Navigation Modules for motion sensing.

Specifications

Sonar Frequency500 kHz
Maximum Operating Depth Below Transducers50 meters
Maximum Swath Width Up to 12 x depth or 150m, depending on conditions and seabed
RangeUp to 75 meters, depending on conditions
Depth resolution6mm (depends on environment and binning)
Slant range resolution1.5mm
Spacing between across track data samplesmin 12mm (range-based sampling)
Two Way Beam Width0.3 Azimuth
Transmit Pulse Length4 S to 500uS
Swath Update RateTypical range setting 35m (~70m swath): 16 pings per second (8 pings per second per side), for 50m Swath Width: 30 swaths per second, for 150m Swath Width: 10 swaths per second (alternates port/starboard).
Along-track data separationDepends on range and speed. For example: 35m rage setting will result in ~16 pings per second (8 pings per second per side), at 4kts speed (2m/s) this will result in 4 pings per metre along-track.​
Pipeline inspection
Pip​eline route surveys
Pre-lay and post-lay pipeline and umbilical installation
Debris tracking and inspection
Search and inspection of wrecks
Hydrographic surveys for dredge works
Navigation channel survey and debris search
General bathymetric, sidescan and camera inspection work
Environmental Surveys