Multibeam Support

HMRG mapping personnel work closely with SOEST’s Ocean Technology Group (OTG) and the Hawaii Undersea Research Laboratory in testing, calibration, and operation of SOEST’s multibeam sonars.  The R/V Kilo Moana  has both deep and shallow mapping capabilities with Kongsberg 12-kHz EM122 and a 70-100 kHz EM710  multibeam sonars.  The R/V Ka’imikai-O-Kanaloa (KoK) is equipped with a 12-kHz Seabeam 3012 multibeam.Currently the OTG is responsible for operation and maintenance of the multibeam sonars, which are run routinely on all cruises and the data are archived as part of the ships’ underway data sets.   HMRG engineers provide support during acoustic testing periods and HMRG’s Seafloor Data Services Manager coordinates geophysical data archiving for SOEST and OTG  and also provides data processing support on test cruises and, as required, on cruises with extensive multibeam usage.

Real-time display of IMI30 sidescan data over previously collected multibeam bathymetry data in Mariana Trench area.

HMRG has developed near-real-time display software for gridded bathymetric and backscatter data which provides scientists with the ability to view newly collected data in superposition to previously gridded data from earlier surveys as well as plan new survey tracklines in relation to such data. This software can be used with either towed HMRG sonars or hull-mounted multibeam sonars. The EM122, EM710 and Seabeam 3012 systems on R/V Kilo Moana and R/V Ka’imikai-O-Kanaloa each have a dedicated computer system running this software which is fully available for science party use. (This software is also currently deployed on other UNOLS vessels including R/V Melville and R/V Thomas G. Thompson.) The ability to geographically view high-resolution bathymetric or side-scan data in near-real time also allows scientist to select sites for detailed sampling or video surveys, including dredging, coring and camera operations.

This bathymetry chart is a typical HMRG product for both multibeam and towed surveys.

This sidescan chart is a typical HMRG product for both multibeam and towed surveys

Routine collection of multibeam data has become a standard protocol over the past decade and all underway data (e.g., multibeam, sub-bottom profiler, magnetics, gravity, ADCP, etc.) that have been collected during cruises funded by the National Science Foundation (NSF) must be submitted to the Rolling Deck to Repository (R2R) within 60 days of acquisition.   The PI may request that data are withheld from public distribution for up to 2 years through R2R and NSF.   These underway data are submitted by the ship’s parent institution (in this case SOEST/OTG)  in raw logged format, usually without any post-processing.  Generally PIs are responsible for further multibeam data processing, but HMRG and/or OTG personnel can also be contracted to provide processing services if the PI does not have the personnel or capability aboard ship.Several processing packages can be made available, including:  HMRG’s own internal software, Science Applications International Corp. (SAIC) SABER processing software; Quality Positioning Services (QPS) Fledermaus processing software; MBSystem, Generic Mapping Tools (GMT) and GeoMapApp, which are open source software tools supported by NSF.   Examples of fully processed and plotted multibeam data collected and processed by HMRG personnel are shown here.