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2023 R/V Sally Ride EM124/EM712 QAT

Cruise ID: SR2307
Multibeam System: EM124/EM712
Dates: April 4-5, 2023

Executive Summary

  1. The R/V Sally Ride (SR) conducted routine quality assurance testing (QAT) on April 4-5, 2023, following the ship’s winter maintenance period
  2. The primary QAT activities included mapping system configuration review and calibration (‘patch testing’) at two sites near San Diego, CA:
    a. EM712 calibration at a proven site used repeatedly by SIO and other vessels
    b. EM124 calibration at a new site southwest of San Clemente Island; this site was developed in order to
    reduce transit time compared to an EM122/124 site used previously (see SR2101 SAT report for details)
  3. The Multibeam Advisory Committee (MAC) assisted with test planning, configuration review, and data
    processing in collaboration with SIO and SR personnel
  4. Planning followed the standard MAC SAT checklist, starting with hardware health, RX noise testing, and calibration; additional testing (e.g., accuracy and swath coverage) was limited by schedule constraints
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    Executive Summary
  5. The EM124 and EM712 calibrations were conducted using post-SR2104 configurations; the results were zero for all but one test (also a small result), indicating stable and consistent mapping system configuration
  6. The current settings should be maintained until any mapping sensors are modified or another calibration becomes necessary for other reasons (e.g., seasonal readiness testing)
  7. EM124 TX Channels BISTs indicated two channel failures since August 2022; while this remains a very low failure rate (out of 864 channels), routine BISTs should be conducted to monitor for additional failures
  8. RX noise vs. speed testing revealed a significant increase in EM124 noise levels since SR2104, presenting a risk of swath coverage and accuracy degradation; because the speed range was limited to 6-9.5 kts in the test data, it is not clear whether the increase is due primarily to higher machinery noise levels that are present at all speeds or other speed- and flow-related impacts (e.g., from biofouling) that may be reduced at low speeds
  9. No EM712 BISTs were available due to errors in continuous logging; this issue was reported to Kongsberg
  10. The MAC is available to assist with EM124 noise level troubleshooting and processing additional EM712 BISTs when logging is restored

Attached Documents

Report:

Sally_Ride_2023_EM124_EM712_QAT_report_v1Download

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