R/V Falkor - EM302 & EM710 Multibeam Echosounder System Quality Assurance Review - FK170602, June 2-8, 2017
Title | R/V Falkor - EM302 & EM710 Multibeam Echosounder System Quality Assurance Review - FK170602, June 2-8, 2017 |
Publication Type | Report |
Year | 2017 |
Authors | Johnson, P, Jerram, K |
Date Published | June 6 |
The R/V Falkor is equipped with both a Kongsberg Maritime (KM) EM302 (30 kHz) and an EM710 (70-100 kHz) multibeam echosounder. These systems have been reviewed for calibration, configuration, and performance almost annually since initial sea trials in 2012, with the most recent prior system Quality Assurance Test (QAT) performed in September of 2015, offshore of Oahu, Hawaii. This report describes the procedures and results of a calibration and performance assessment conducted during leg FK170602 (June 2-8, 2017) which was used to verify system functionality immediately following a significant shipyard period.
Changes to the multibeam systems since the September 2015 visit include occasional patch tests during the 2015-17 mapping missions, followed by removal, factory calibration, and reinstallation of the Seapath 320 MRU and the Applanix POS MV V5 IMU during the 2017 dry dock period. The FK170602 post-shipyard evaluation included full geometric calibrations (patch tests, with verification lines where appropriate) for the EM302 and EM710 using the Seapath 320 and Applanix POS MV motion sensors as the primary position and attitude feeds. Transmitter element impedance measurements were collected for both systems to identify any early warning signs for possible transducer degradation. Vessel noise measurements were collected while operating under a variety of speeds and headings relative to the prevailing swell to evaluate changes in the platform noise environment; these results are outlined in a separate report by Gates Acoustic Services. Finally, swath coverages as a function of depth were examined for both echosounders using data collected throughout FK170602 in depths of 15-2,500 m.
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