EM122

Kilo Moana 2015 EM122 MBES Review

Multibeam System: 
EM122
CruiseID: 
KM1514

Introduction

Kilo Moana 2015 Acoustic Test Report

Multibeam System: 
EM122

Executive Summary

Conclusions

  • The EM 122 receive array had a bad preamplifier board that was causing the entire array to have higher noise levels and to exhibit non-uniform distribution of noise characteristics.2.The EM 122 receive array module 6 was out of phase with the rest of the sonar receive array.
  • The EM 122 receive array module 6 was out of phase with the rest of the sonar receive array.
  • Propeller cavitation performance was good and consistent with previous results.

Nathaniel B. Palmer 2015 Sea Acceptance Report

Multibeam System: 
EM122
CruiseID: 
NBP1505

Executive Summary

The research vessel icebreaker (RVIB) Nathaniel B. Palmer (NBP) undertook cruise NBP1505 in the vicinity of the continental shelf break between Talcahuano and Puerto Montt, Chile, from June 10-15, 2015 (Fig. 1) in order to assess performance of the vessel’s 12-kHz multibeam echosounder (MBES). The MBES consists of a Kongsberg Maritime (KM) EM122 transceiver installed in June 2014 and transmit (TX) and receive (RX) arrays installed in June 2015, prior to NBP1505.

Healy 2014 Acoustic Test Report

Gates Acoustic Services was tasked by SCRIPPS Institute of Oceanography to investigate and quantify acoustic issues associated with operation of the USCGC HEALY (WAGBG20). An at-sea investigation was accomplished during ship operations in deep water out of Nome, Alaska on August 13-24, 2014.

Nathaniel B. Palmer 2014 Sea Acceptance Report

CruiseID: 
NBP1405

The Kongsberg Maritime (KM) EM120 multibeam echosounder (MBES) aboard the RVIB Nathaniel B. Palmer (NBP), installed in 2002, recently received two upgrades through the installation of a KM Seapath 330 position and attitude sensor (November, 2013) and replacement of the original EM120 transceiver with an EM122 transceiver (June, 2014).

Roger Revelle 2013 Quality Assurance Report

CruiseID: 
RR1301

The accuracy (repeatability, strictly speaking) analysis indicates that the system is performing within expected levels. The EM122 appears to be configured correctly and adequately calibrated. A full patch test calibration was conducted with the offsets being applied in SIS; follow up confirmation calibrations indicate that the offsets are correct. A residual bias exists in the system that is associated with the multibeam system itself and not the MRUs (as it was common to both the Hydrins and Seapath).

Kilo Moana 2012 Sea Acceptance Report

CruiseID: 
KM1212

The EM122 and EM710 systems both appear to be configured correctly and, for the most part, adequately calibrated. Small MRU roll alignment residuals do exist and it is recommended that these be confirmed as soon as possible through acquisition of a pair of reciprocal survey lines over a flat and featureless seafloor. Verification lines should have been run for calibration tests for both systems, however, time constraints on the cruise schedule precluded this. It is standard practice to run verification lines.

Kilo Moana 2012 Acoustic Test Report

KILO MOANA’s acoustic signature was higher than previous acoustical data due to electronic noise interference. The levels in the EM 122 sonar operational frequency of 12 kHz were also higher than historic data. A significant problem was noted with numerous elements of the EM 122 sonar array that is believed to be associated with electronic background noise. Electronic noise was determined to be the major deficiency during this acoustic trial.

Kilo Moana 2012 Quality Assurance Report

CruiseID: 
KM1204

The point of the QAT visit was to help the host institution in developing protocols and practices that are conducive to the acquisition of high quality multibeam data. Even with a finely tuned and calibrated survey system, it is still possible to collect poor quality data through poor choice of operational system parameters, etc. Software tools to aid in this regard were deployed and documentation was prepared that can help return the system to a healthy configuration such that the institution can recover from a sub-optimal system configuration.

Kilo Moana 2010 Acoustic Test Report

KILO MOANA’s acoustic signature was comparable to previous acoustical data with one noted exception. The levels in the EM 122 sonar operational frequency of 12 kHz were similar to historic data. A new problem was discovered that was associated with engine and switching room air handler cooling systems. This problem created 4,000 Hz harmonics from the fundamental up through 80 kHz (the limit of onboard instrumentation). An additional problem was noted with numerous elements of the EM 122 sonar array that is believed to be associated with electronic background noise.

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