1. Optimizing Multibeam Data Quality Across the Fleet TIM GATES (Gates Acoustic Services) VICKI FERRINI (LDEO) JONATHAN BEAUDOIN (CCOM-UNH) PAUL JOHNSON (CCOM-UNH) JOHN HUGHES CLARKE (OMG-UNB)

2. Background MB workshop at NSF June 2010 in response to fleet-wide issues with multibeam performance Goals: Discuss operation of the sonars Identify common threads in documented problems Get advice from domain experts and other MB users Outcomes: Identified several specific operational and technical issues, some poorly understood, impacting multibeam data quality Identified a strong need to coordinate operational and technical efforts across the fleet

3. UNOLS FLEET SCRIPPS MELVILLE ROGER REVELLE WHOI KNORR ATLANTIS UW – THOMAS THOMPSON UH – KILO MOANA LDEO – MARCUS LANGSETH

4. Multibeam Advisory Committee (MAC) Fleet-wide Approach Facilitate Communication Community of Stakeholders Technical Resources Technical Teams Shipboard Acceptance Acoustic Noise Quality Assurance Best Practices Transition into a UNOLS Committee

5. MAC: Committee Planning In-person meeting once per year Supplement with Telecon/Web Conferencing Review Technical Team activities & products Prioritize ship visits Address practical implementation of best practices Discuss concerns/issues from Operators Ensure MAC is providing necessary resources

6. Overview of Technical Teams ANT and SAT: help optimize ship and system performance QAT: help optimize the way data is acquired

7. MAC: Acoustic Noise Team Goal: Perform acoustic noise tests to assess and potentially improve sensor efficiency (coverage) and data quality Establish baseline noise levels Help populate an archive of historical data on noise properties of each vessel to aid in monitoring over sensor lifetime Anticipate 2 ship visits per year

8. MAC: Shipboard Acceptance Team Goal: Ensure all hull-mounted multibeam systems are installed, calibrated, and configured properly and consistently Participate in Sea Acceptance Trials for new and/or poorly understood existing installations Anticipate 2 ship visits per year

9. MAC: Quality Assurance Team Goal: Ensure multibeam sonar systems are operated in a consistent manner that maximizes data accuracy, precision, and scientific utility Develop and disseminate best practice documentation Develop and deploy tools and procedures to optimize data quality during acquisition

10. Technical Teams in Action

11. Acoustic Noise Testing It is planned to acquire baseline acoustic signatures from each UNOLS vessel Signatures will be acquired from test hydrophones and internal sonar noise routines Results of acoustic testing will determine: Propeller cavitation Hydrodynamic flow noise Machinery contributions Bubble sweepdown impacts Data will be archived for future comparisons and trending of noise backgrounds

12. Acoustic Testing R/V MELVILLE was tested in January R/V KILO MOANA is scheduled for testing in June Previous tests (prior to the MAC) have been accomplished on: R/V REVELLE R/V KILO MOANA R/V MARCUS LANGSETH R/V ATLANTIS

13. Benefits of Acoustic Testing Identify acoustic deficiencies that limit full sonar performance Provide corrective actions for problem areas Develop “quiet” machinery line-ups for best performance Develop operational guidance to mitigate acoustic noise issues

14. Recent Acoustic Findings ATLANTIS – has a cavitating gondola LANGSETH – quieter at 9 knots than 0 to 8 knots due to controllable pitch propellers KILO MOANA – Above 9 knots data is controlled by diesel engines which limit sonar performance MELVILLE – anti-roll system limits sonar performance during roll cycles REVELLE – bubble sweepdown transients limit sonar performance in higher sea states

15. QAT: R/V Kilo Moana Ship Geometry Verification Verification of current system geometry by establishing “chain of custody” by reviewing: Ship drawings Blom survey (2005): initial survey of mapping system offsets Applanix site visit reports (2006 & 2008) IMTEC survey (2012): survey of new EM710 installation Independently established linear and angular offsets from above documentation and verbal reports of configuration changes Found and corrected errors in current configuration: Primary GPS location in POS/MV configuration Pitch offset in EM710 configuration

16. QAT: R/V Kilo Moana Assessment of Documentation Found hardcopy and softcopy operators manuals for EM122 and EM710 Found out-dated “cookbooks” for EM1002/EM120 on technician’s wiki Newer “cookbooks” generated for EM710/EM122 and focused on SIS How to backup all system settings How to uninstall SIS and remove the database How to re-install SIS and import system settings to get system back to last known good configuration

17. QAT: R/V Kilo Moana Software Deployment: SVP Editor Graphical display and editing of XBT data: can interact with data to remove outliers Implements proposed best-practices: Augment with database salinity profile (World Ocean Atlas 2009) Embed measured surface sound speed in upper layer Use database for vertical extension of cast Server mode: automatically delivers World Ocean Atlas sound speed profiles to SIS while in transit Streamlined processing allows for delivery of cast to SIS for immediate application SIS

18. QAT: R/V Kilo Moana Software Deployment: BIST Logger python script to log BIST output over network via UDP Includes vessel position/speed and engine RPMs; reduces requirement to embed “metadata” in filenames, e.g. starboard_engine_200_rpm_5kts_045_heading_BIST.txt Enables acquisition of rich acoustic noise data sets with minimal effort Results from acquisition of 294 BIST noise spectrum measurements over 38 minute time span with gradual increases in ship speed. Achieved with one operator repeatedly launching the appropriate BIST test; all data and metadata were logged automatically. Plot generated with Matlab.

19. We value your input! You can benefit: Reports and tools will be available publicly online You can contribute also: Best practice documentation Ideas Multibeam Horror/Success stories

20. http://mac.unols.org/