The 3-D-V Array: A Digital, Volumetric, 3-D Towed Hydrophone Array - PowerPoint PPT Presentation

3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel The 3-D-V Array: A Digital, Volumetric, 3-D Towed Hydrophone Array System Capable of Bearing and Location Estimation in 3-D Space Tom Norris Bio-Waves Inc. Gerald D’Spain Scripps Institution of Oceanography-UCSD Douglas Gillespie SMRU-University of St. Andrews 13 September 2018 1 The Hague, The Netherlands

Research Rationale The rational for this R&D effort is to develop a more effective towed hydrophone array system for monitoring of marine mammals and for mitigation of E&P activities in real time. 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

The Problem(s) • Marine mammals occur in a complex 3-D environment, however most ‘traditional’ linear towed array systems are limited to localization in 1-D (bearing only) or 2-D space. • Some issues include • Left/Right Ambiguity • Localization of deep-diving species (e.g. sperm whales and beaked whales) • Changes in array orientation/shape or depth (flexible, linear arrays) • Noise (both system noise and environmental/ambient noise) 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

The Problem(s) Seismic survey vessel PAM / mitigation exclusion/mitigation zone 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

The Problem(s) – Linear Towed Arrays • Left/Right ambiguity • Slant angle/ranges for Deep-Divers • 2-D projection of data 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

The Problem(s) - Noise System Noise Ambient and ship noise • Self-noise introduced into the system • Most noise is not isotropic • Analog arrays have major noise issues (i.e. it is directional) • ‘clean power’ is a big problem • Self-ship noise can be an issue • Air-gun arrays add significant noise 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

The Solution • A digital 3-D (i.e. tetrahedral) towed hydrophone array system • Dynamic orientation sensors (e.g., accelerometer, a pressure sensor, and a magnetometer/compass) to correct for array orientation. • Improved real-time signal & array processing capabilities 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Objectives & Goals • To design and develop a tetrahedral towed hydrophone array system with the following capabilities and features: • easy to deploy, operate and maintain • Digitization of analog data at the wet-end (i.e. at the tow body) • real-time acoustic and array sensor data processing using PAMGuard • designed to operate with minimal effects on seismic survey operations . • Conduct extensive field testing, including tests from both small boats and a large seismic survey vessel . 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Software Development Goals • Structural modifications to PAMGuard to interface with digital data • Development of additional ‘modules’ and capabilities: • A ‘ beamformer module’ and GUI • General Power Law (GPL) automated detectors • 3-D localization graphics 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Implications We expect this system to be used on seismic exploration vessels during oil and gas exploration and production activities that require real-time monitoring of marine mammals. NOAA has funded development of similar technologies but these systems were intended for marine mammal research surveys. 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

‘X - array’ tetrahedral array design (original design idea from NOAA-SWFSC and funded by NOAA-SBIR) 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

3-D-V tetrahedral design • Hydrodynamic struts and hydrophone pods to minimize turbulence • Modular design to allow easy changing of hydrophones and struts 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

3-D-V Array Exoskeleton • HTI-HF99 hydrophones located in ‘nacelles’ (pods front of red caps) 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

3-D-V Array Data Acquisition System Low-Pass Filter 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

3-D-V Array Electronics Package • 4 acoustic channels digitized @ 125 KHz/channel (16 bits) • 7 channels of non-acoustic sensor data digitized @10 Hz/channel (16 bits) • 40+ channels of non-acoustic engineering data. Attitude, Single heading board sensor computer Signal conditioning wideband board DSL modem 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Small Boat Field Tests map Sound source located at end of SIO pier; ITC3013 sound CPA ~500 m source 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Small Boat Field Tests • Two series of field tests conducted in Spring and Fall 2018 (one more planned for tomorrow!) 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Deployment from Small Boat • Blah Blah • Blah Blah 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Deployment from Small Boat 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel ISSUES IDENTIFIED DURING TESTS • Hydrophone connector termination problem (now repaired) • Overheating of electronics • power supply (Spring Tests) • computer board (Fall Test) (Heat-sink materials installed to address overheating issues)

RESULTS - Non-Acoustic Sensor Data • Oscillations (~0.2 Hz) are evident in, pitch pitch roll & heading in roll • Latest tests had a decrease in pitch but not much in roll & heading heading • lead weight can be added to the depth array and/or tow-cable to increase depth and stabilize array . Tow speed ~ 4 knots 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Beamforming Out of In Phase Phase Data-Adaptive Single Element Conventional 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Beamformer Performance Conventional Adaptive Realizations (%) Bearing Error (deg) Bearing Error (deg) Bearing Error (deg) * No correction was made to account for the offset of the array itself from the towing boat 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

PAMGuard Beamformer Module Doug Gillespie will be providing a demo later today 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

Seismic Vessel Field Test R/V Langseth – Columbia University/LDEO Seismic Research Vessel Planned for late Fall/Winter 71.5m/ 235 ft 3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel

3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel Summary ● Designed and constructed a tetrahedral towed array system & electronics. ● Developed beamformer modules, new detectors and 3-D localization in PamGuard. ● Conducted tests from small boats that allowed us to identify issues and resolve them before final tests are conducted on large (expensive) survey vessel. ● Preliminary quantitative evaluation of bearing estimation using adaptive beamforming yielded good results using the 3-D-V array. ● Will continue to conduct field tests assess and improve system performance.

3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel Acknowledgements • JIP – David Hedgeland (Tech Rep) & John Campbell • Bio-Waves – Liz Ferguson (assistant project manager) Mike Oswald (programmer); • SIO/UCSD – Dennis Remington / David Price (engineers) • LDEO – Jeff Rupert Sean Higgins (Research Vessel Support) www.biowaves.net www.pamguard.org/ scripps.ucsd.edu/mpl

3 r d P R O G R A M M E R E V I E W M E E T I N G 9 - 14 September 2018 ؞ The Hague, Netherlands ؞ Carlton Beach Hotel Questions?