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

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

The 3-D-V Array:

A Digital, Volumetric, 3-D Towed Hydrophone Array System Capable of Bearing and Location Estimation in 3-D Space

1

Tom Norris Bio-Waves Inc. Gerald D’Spain Scripps Institution of Oceanography-UCSD Douglas Gillespie SMRU-University of St. Andrews

13 September 2018 The Hague, The Netherlands

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

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.

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

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)

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

The Problem(s) Seismic survey vessel PAM / mitigation exclusion/mitigation zone

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

The Problem(s) – Linear Towed Arrays

• Left/Right ambiguity
• 2-D projection of data
• Slant angle/ranges for Deep-Divers

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

The Problem(s) - Noise

System Noise

• Self-noise introduced into the system
• Analog arrays have major noise issues
• ‘clean power’ is a big problem

Ambient and ship noise

• Most noise is not isotropic

(i.e. it is directional)

• Self-ship noise can be an issue
• Air-gun arrays add significant noise

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

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

• rientation.
• Improved real-time signal & array processing capabilities

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

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.

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

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

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

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.

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

‘X-array’ tetrahedral array design

(original design idea from NOAA-SWFSC and funded by NOAA-SBIR)

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

3-D-V tetrahedral design

• Hydrodynamic struts and hydrophone pods to minimize turbulence
• Modular design to allow easy changing of hydrophones and struts

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

3-D-V Array Exoskeleton

• HTI-HF99 hydrophones located in ‘nacelles’ (pods front of red caps)

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

3-D-V Array Data Acquisition System

Low-Pass Filter

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

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.

Signal conditioning board Single board computer wideband DSL modem Attitude, heading sensor

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

Small Boat Field Tests

map

ITC3013 sound source

CPA ~500 m

Sound source located at end

• f SIO pier;

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

Small Boat Field Tests

• Two series of field tests

conducted in Spring and Fall 2018

(one more planned for tomorrow!)

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

Deployment from Small Boat

• Blah Blah
• Blah Blah

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

Deployment from Small Boat

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

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)

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

RESULTS - Non-Acoustic Sensor Data

• Oscillations (~0.2 Hz) are evident in,

pitch roll & heading in

• Latest tests had a decrease in pitch

but not much in roll & heading

• lead weight can be added to the

array and/or tow-cable to increase depth and stabilize array.

Tow speed ~ 4 knots pitch roll heading depth

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

Beamforming

Single Element Conventional Data-Adaptive In Phase Out of Phase

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

Beamformer Performance

Bearing Error (deg) Bearing Error (deg) Bearing Error (deg) Realizations (%)

Conventional Adaptive

* No correction was made to account for the offset of the array itself from the towing boat

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

PAMGuard Beamformer Module

Doug Gillespie will be providing a demo later today

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

Seismic Vessel Field Test

R/V Langseth – Columbia University/LDEO Seismic Research Vessel

Planned for late Fall/Winter

71.5m/ 235 ft

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

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.

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

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

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

Questions?

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

ADDITIONAL SLIDES (FOR DISCUSSION/QUESTIONS)

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

PAMGuard Beamformer Module

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

PAMGuard Beamformer Configuration Display

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

RESULTS – Acoustic Test Data

Snew Nnew 1 4 3 2 (2-m resolution)

• Bathymetry off the SIO Pier test site
• Note that a deep submarine canyon

was traversed during small boat tests

• Transmission Loss was highly

dependent (~ 30 dB) on azimuth

Tracks above offset so they can be seen.

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

Signal Received Level in Select Frequency Bins

TL = SL - RL Nnew Snew

• Transmission Loss

is highly dependent (~ 30 dB) on azimuth

• drop in received signal level

due to water depth differences of tens of meters encountered as the array is towed across the upper submarine canyon

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

RESULTS – Beamformed Acoustic Data

Noise is strongly dependent (~ 10 dB)

• n azimuth

(i.e. its directional)

Forward looking (self-ship noise)

Frequency / Azimuth Plot

• f “Background Noise”

Left side

• f array

Right side

• f array

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

RESULTS - Non-Acoustic Sensor Data

Variation in Non-Acoustic Sensor Data (with 4.8 lb in lower, forward strut)

Tow Speed Strain Pitch Roll Heading Depth

3 kt 16 lb ± 3 lb 5° ± 5° -10° ± 2° 340° ± 3° 6.5 m ± 0.2 m 5 kt 22 lb ± 6 lb 3° ± 7° -20° ± 5° 340° ± 15° 3.5 m ± 0.3 m 7 kt 30 lb ± 8 lb 3° ± 8° -60° ± 10° 340° ± 10° 1.8 m ± 0.4 m