R2Sonic has added MultiSpectral Mode™ survey capability, an innovation allowing R2Sonic systems to collect backscatter data at multiple frequencies in a single pass, with one vessel and one sonar system. Multi-frequency backscatter is an active area of research and promises great results in the area of bottom classification.
At GeoHab 2016, in May, Dr. Jonathan Beaudoin, Chief Scientist at QPS, and Dr. Craig Brown, NSERC Industrial Research Chair in Integrated Ocean Mapping Technologies at Nova Scotia Community College, presented the first results of using this mode with the Sonic 2026 in Bedford Basin, near Halifax in Nova Scotia, Canada. In addition to high-resolution 3D bathymetry, the Sonic 2026 (with Low Frequency option) also collected backscatter Snippets at 100kHz, 200kHz and 400kHz. MultiSpectral Mode™ accomplishes all of this in a single pass, drastically reducing survey time and eliminating any artifacts from environmental variables that might change between separate surveys.
“We now have a purpose-built surficial geology and habitat mapping sonar, giving us the opportunity to use the multi-frequency capability for accurate identification and segmentation of seafloor features of interest and opportunities to explore new segmentation routines” stated Dr. Brown. Potential uses include efficient mapping of seafloor characteristics, bottom type discrimination and feature identification, as well as habitat mapping for environmental applications.
In addition to the traditional Snippet data format, all R2Sonic Multibeam Echosounders also support TruePix™. TruePix™ is an improved backscatter format that is generated independently from the multibeam bottom detect, like digital side scan. Unlike Snippets, TruePix™ assembles the imagery record with one sample per range bin per side. There are no overlapping data pieces to be merged and reduced into a single record, which produces uniform quality data and also reduces file sizes. TruePix™ can also record the angle associated with each imagery point, whereas Snippets only reports the angle of the center point of each Snippet. This increases the number of angular measurements by an order of magnitude or more, for finer backscatter and bathymetry co-registration.