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Service + Software for Seafloor Mapping
Digital Sidescan Sonars / Overview
Digital sidescan sonars are functionally identical to analog sonars, i.e., they ping (transmit) and listen for echoes, which are recorded as backscatter from the seabed. Images are built up by recording sequential pings.
The chief distinguishing factor of digital sidescans is that they output digital data, as opposed to analog voltage signals. True digital systems digitize the sidescan data in the towfish, so that the data can be transmitted noise-free over longer cables than would be possible with analog sidescans.
The digitization dynamic range (8, 12, 16 or 32-bit) and resolution (sample rate) is controlled by the sonar. GeoDAS simply receives the digitized data and records it raw in OIC format, providing any user-supplied real-time processing for display.
Interfaces for digital systems are usually serial (USB or RS-232/485), Parallel, High-speed serial (SDLC) or Ethernet, the latter being most common in high-resolution systems. GeoDAS provides specialized interfaces for each system, as detailed on the Digital Sidescan Sensors pages.