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MULTIBEAM AND CHIRP

During the cruise c.a. 1200 km of CHIRP profiles have been acquired in the Bari canyon and offshore the Gargano Promontory, using the hull-mounted BENTHOS CHIRP II Mod.CAP-6600 by Communication Technologies (16 transducers, 2 -7 kHz range, 20 ms pulse length). The trigger rate varied among 0.25 and 1 s, depending on water depth. Digital data was recorded by the software SWANPRO (Communication Technologies) and stored in XTF format. Positioning was DGPS-based (1 Hz).

Along with the CHIRP profiles, multibeam bathymetry was acquired by means of the Kongsberg-Simrad EM710 and recorded by the SIS - Seafloor information system. The multibeam system operates with frequencies between 70 and 100 kHz and owns a resolution of 1°x 1°. Swath range is about 5 times the water depth in 500-700 m. For deeper depths, 1000 m, the swath decreases up to 1.5 times the water depth. During the survey, the reliability of the depth to swath diagram given by Kongsberg has been verified. The multibeam system has shown a strong interference with the hull-mounted ADCP (Acoustic Doppler Current Profiler) and did not work properly.


next up previous contents
Next: METEOROLOGICAL DATA Up: MATERIALS AND METHODS Previous: MICROSTRUCTURE TURBULENCE PROFILER   Contents
2009-12-16