Introduction
High-resolution swath bathymetry combined with co-registered backscatter information is acquired via a Kongsberg Simrad EM3000 shallow water multibeam sonar system. The system is integrated with precise positioning, motion and heading sensors providing cm-scale resolution and unprecedented repeatability. Data is acquired and processed with the Triton Elics International suite of hydrographic software and can be exported into ANY commercial or open source GIS/CAD applications. The system can be run from our custom-made research vessel or mobilized on any vessel of opportunity.
 

Multibeam Acquisition Station	Navigation and Helm Station
Sonar Head, Motion Sensor, and GPS	Gyro-Compass Setup
Technical Specifications

MULTIBEAM TRANSDUCER • Simrad EM 3000 multibeam sonar transducer o Frequency: 300 kHz o Max ping rate: 40 Hz o No. of beams/ping: 127 o Beam width: 1.5o x 1.5o o Beam spacing: 0.9o o Depth range from sonar head: 1 to 150 m o Depth resolution: 1 cm o Depth accuracy: 5 cm RMS o Range sampling rate: 15 kHz o Bottom detection by phase or amplitude. o Seabed imaging & classification with backscatter output. o Full swath width accuracy to the latest IHO standard HEADING SENSOR • VT TSS Meridian Surveyor gyrocompass o Settle point: 0.1o secant latitude o Static accuracy: 0.05o RMS secant latitude o Dynamic accuracy: 0.2o secant latitude o Follow up speed: 200o /sec o Settling time: <40 minutes to within 0.7o MOTION SENSOR • VT TSS DMS-10 motion sensor o Dynamic heave accuracy: 5 cm o Dynamic pitch & roll accuracy: 0.07o o Output rate: 200 Hz

POSITIONING INSTRUMENTS • Trimble 5700 dual frequency GPS system & RTK-Basestation o Instrument used for topo/bathy positioning and tidal corrections o High precision L1 and L2 measurements o 24 channels L1 C/A code, L1/L2 full cycle carrier o Extremely low latency (20 milliseconds) o RTK-GPS accuracy depends on conditions such as multipath, obstructions, satellite geometry, atmospheric parameters and basestation control quality. - Published horizontal accuracy: 10 mm + 1ppm RMS - Published vertical accuracy: 20 mm + 1ppm RMS • Garmin WAAS enabled differential GPS system o sub-meter precision in WAAS mode SOUND VELOCITY INSTRUMENTS • Odom Hydrographics Digibar Pro sound velocity probe o Sampling rate: 10 Hz o Depth accuracy: > 31 cm o Velocity accuracy: +/- 0.3 m/sec