EM302

E/V Nautilus Spring 2017 Quality Assessment Report

Multibeam System: 
EM302
CruiseID: 
NA079
The E/V Nautilus undertook a multibeam echosounder quality assurance test from May 1 to May 5, 2017 during an engineering shakedown leg (NA079) in order to perform an assessment of the vessel’s Kongsberg EM302 multibeam echosounder. Data were collected near the Southern Channel Islands (Figure 1), offshore from San Pedro, California. Paul Johnson and Lindsay Gee provided logistical and technical support for mission planning, data collection, and analysis.

Summary and Recommendations:

RV Sikuliaq 2016 Calibration Report

CruiseID: 
SKQ201602S

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.

RV Bat Galim 2016 System Review

From January 31st to February 4th, 2016 a Shipboard Acceptance Testing (SAT) was conducted on the R/V Bat Galim, owned by the Ministry of National Infrastructures, Energy and Water Resource of Israel and operated by Israel Oceanographic and Limnological Research, on the newly installed Kongsberg Maritime (KM) EM302 (30 kHz) and EM2040 (200 kHz, 300 kHz, and 400 kHz) multibeam echosounders. These systems were thoroughly reviewed for system geometry, calibration, configuration, and performance during this acceptance period. Documented in this report are:

RV Bat Galim 2016 Acoustic Test Report

During the at-sea test on BAT GALIM, the main objective was to determine ship acoustic characteristics and to assess potential impacts to sonar performance from all acoustic sources. The primary sonars of interest were the newly installed Kongsberg EM 302 and EM 2040 multibeam systems. The following evaluations were accomplished as part this testing:
  1. The overall noise levels of BAT GALIM were measured and characterized with special test sensors and internal noise routines inherent in the Kongsberg sonars.
  2. Propeller cavitation characteristics were assessed.

E/V Nautilus Spring 2014 Quality Assessment Report

Multibeam System: 
EM302
CruiseID: 
NA040

Summary and Recommendations

  • As it stands now, the EM302 and associated sensors are working well as compared to other EM302s evaluated recently. The patch test revealed very slight residual angular offsets, indicating a successful reinstallation of the MRU and no apparent change to any other component of the system.

E/V Nautilus Spring 2015 Quality Assessment Report

Multibeam System: 
EM302
CruiseID: 
NA055

Summary and Recommendations

  • Heading into the 2015 operating season, the EM302 and associated sensors aboard E/V Nautilus are working well compared to previous evaluations and to other EM302 systems examined recently. The patch test showed no pitch or yaw bias and only a very slight residual angular offset for roll, indicating no major changes to the system geometry.

Sikuliaq 2014 Acoustic Test Report

Gates Acoustic Services was tasked by University of Alaska, Fairbanks, to investigate and quantify acoustic issues associated with operation of the R/V SIKULIAQ. An at-sea investigation was accomplished during ship operations in deep water out of San Juan, Puerto Rico on September 12-18, 2014.

Falkor Fall 2014 Quality Assessment Report

The EM302 and EM710 multibeams were successfully calibrated and verified for use with both the loaner Seapath MRU and the new POS MV. Angular offsets were small except for the roll bias for both the EM710 and EM302. As both multibeam systems have the same large roll bias, it is likely the result of a shift in the mounting angle of the MRU. Both SIS acquisition systems have been updated with the new calibration results.

Falkor Spring 2014 Quality Assessment Report

The transducer impedances are similar to baseline measurements in 2012 and with those taken in 2013. Transducer conditions, based on these tests, are acceptable and there is no sign of degradation of the transducer arrays.

Noise levels for the EM710 remain unchanged and very low. Noise levels for the EM302 have increased at higher speeds though they remain low when the ship is stationary in the water, suggesting that the increase is associated with flow noise and/or the propulsion system.

Falkor 2013 Multibeam Echosounder System Review

The transducer impedances are similar to baseline measurements with exception of the EM710 transducer impedances. This latter potential issue is being examined with the manufacturer but we do not feel, after consultation with the manufacturer, that there is any cause for concern. Noise levels have not changed significantly since the 2012 trials in “Science” mode. Review of the noise results by Tim Gates indicates that there are some modules reporting higher noise levels compared to measurements taken by Gates in early 2012 and may warrant a closer investigation

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