First data from sea trials with the new MS70 multibeam sonar

The new multi‐beam sonar, MS70, is a horizontally observing sonar yielding very high spatial resolution when operating all 500 beams, covering the frequency band 75–112 kHz. The sonar has undergone sea trials from R/V G. O. Sars from December 2005. The presentation includes preliminary results obtained during this period. Topics covered will be sonar performance objectives, calibration methods, and preliminary results from calibration and school data acquisition. Examples of raw and processed 3‐D and 4‐D data from a stationary and surveying vessel on small sprat schools and large herring schools will be shown.