HR: 1330h
AN: OS32A-0238    [PDF]
TI: A New Method For Processing Backscatter Imagery Collected By Multibeam Sonars: The HAWAII MR1 Sidescan Sonar Software Suite
AU: * Davis, R
EM: rbd@soest.hawaii.edu
AF: SOEST - University of Hawaii, 1680 East-West Road, Honolulu, HI 96822
AU: Appelgate, B
EM: tba@hawaii.edu
AF: SOEST - University of Hawaii, 1680 East-West Road, Honolulu, HI 96822
AB: The Hawaii Mapping Research Group of the University of Hawaii has developed and used in-house software to process seafloor acoustic imagery (sidescan sonar) data acquired by its own shallow-towed HAWAII-MR1 phase-difference sidescan bathymetry mapping system, as well as phase-difference sonars operated by other institutions (NAVO SEAMAP-C, LDEO SCAMP, WHOI DSL-120A). During 2003 the HAWAII MR1 software tools were modified to operate on multibeam backscatter data collected by the University of Hawaii research vessel Kilo Moana to test whether the software could improve the quality of the multibeam backscatter and the resulting data products. We found that the MR1 processing tools are effective in eliminating speckle and stripe noise, and cross-track amplitude variability due to angle-varying gain. HMRG software was also used to produce final mosaics of sonar imagery. Once we determined the viability of using the MR1 tools to process Kilo Moana data, we expanded the toolkit to allow operation on data from other multibeam systems as well. HMRG processing software runs on Linux, Unix and Irix platforms. The main processing modules can be run in either graphical or command-line modes. The preferred processing scheme involves using the graphical interface to interactively determine noise filters appropriate for each survey. Once characterized, these filters are then applied in batch processes that run faster than graphical methods allow. Once processing is completed, the HMRG software is used to grid the data and then to assemble individual grids into mosaics. The mosaics can be output as Sun raster files, geotiffs, or Generic Mapping Tools (GMT) grids, which allow the mosaics to be imported into other GIS and charting programs. Here we present results from several recent surveys that used different hull-mounted multibeam systems: 12kHz Sea Beam 2112 data from the US Coast Guard Cutter Healy, 12kHz Simrad EM120 data from deep water surveys aboard the R/V Kilo Moana, shallow-water 95kHz EM1002 imagery from R/V Kilo Moana, and very shallow-water 240kHz survey data collected using a Reson 8101 aboard the National Oceanic and Atmospheric Administration survey launch R/V AHI. This new application of HAWAII MR1 software provides users of these systems a new, flexible approach to cleaning, displaying and disseminating backscatter imagery from multibeam sonars.
UR: http://www.soest.hawaii.edu/hmrg
DE: 0994 Instruments and techniques
DE: 1294 Instruments and techniques
DE: 3045 Seafloor morphology and bottom photography
DE: 3094 Instruments and techniques
DE: 4294 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting