Cruise ID: R/V Marcus G. Langseth
Multibeam System: EM122
Dates: February 04-07, 2011
The R/V Atlantis replaced its EM122 multibeam echosounder with an EM124 upgrade during the 2020-21 R/V MARCUS G. LANGSETH’s acoustic signature was successfully measured during this acoustic test. The levels of the EM 122 were controlled by propeller cavitation. The quietest vessel condition/speed was when the controllable pitch propellers were set to 85 percent pitch with an engine speed of 600 RPM. This yielded a ship speed of 10 knots and a sonar level of 52 dB. The seismic system created high levels when it was operating.