The R/V Sikuliaq is equipped with Kongsberg Maritime (KM) EM302 (30 kHz) and EM710 (70-100 kHz) multibeam echosounders and a Seapath 320 positioning and attitude system with C-NAV DGNSS auxiliary input. These systems were reviewed by the Multibeam Advisory Committee (MAC) and personnel from NOAA, the University of Alaska Fairbanks (UAF), and Kongsberg Maritime (KM) during sea acceptance trials (SAT) in August 2014. No major modifications were made to the multibeam systems following the SAT until a drydock period in early 2016, during which the Seapath 320 GPS antenna separation was increased to approximately 2.5 m to better satisfy KM installation suggestions. The C-NAV GCGPS antenna was also relocated from a lower position to between the Seapath antennas to improve its sky view.
The MAC was requested to review the modified system configuration and perform geometric calibrations (‘patch tests’) of the multibeam systems during a coring shakedown cruise northwest of San Diego. This report describes the procedures and results of the calibrations conducted during cruise SKQ201602S (March 9-12, 2016) in order to verify functionality following the antenna relocation. In addition to geometric calibrations, transmitter element impedance measurements were collected for both systems to identify early warning signs for any possible transducer degradation. Swath coverage versus depth was examined for both echosounders using data collected throughout transits and surveys of opportunity for other activities during SKQ201602S in depths of 10-2,000 m.
|SKQ201602S MAC Report||6.85 MB|