Simon Barchard, RESON

The use of MBES for bottom classification, leak

Multi-beam Echo-sounders (MBES) not only for bathymetry

Document pathwww.reson.com

The use of MBES for bottom classification, leak

detection, harbor protection and more.

by Simon M. Barchard

RESON

SECURITY DESIGNATION

Agenda

● Introduction

● MBES in survey configuration (bottom looking)

Bottom Classification

Sunken Heavy Oil Detection

● Forward looking MBES

Water side security (harbor protection)

Leakage Detection


Leakage Detection

● Q & A


Introduction

● Advanced uses of MBES data require processing and integration with motion and other sensors

● PDS2000 is the backbone of RESON’s advanced processing solutions

● Some facts about PDS2000:PDS2000 Multibeam is a Hydrographic Survey software suiteVersions for Multibeam, Singlebeam and Dredging

Integrated multibeam data acquisition, navigation and guidance.

Handles SeaBat 7k bathymetry, snippets and sidescan.Interfaces to all commonly used navigation sensorsScalable to installations with multiple sensors


Scalable to installations with multiple sensors3D Multibeam Data Editor with integrated CUBE processingData modeling & Volume computationsData export to a variety of formats

● The SeaBat 7k platform is used for advanced applications● Capabilities include:

BathymetryBackscatter (sidescan and/or snippets)Forward looking sonar imageryWatercolumn mapping


Introduction continued…

Snippet

data

PDS2000 also allows for interactive data processing of data with

snippets and CUBE


CUBE

Model

An explanation of snippets will follow later in the presentation

Bottom Classification Backscatter corrections

GeoCoder is the tool used by PDS2000 to perform bottom classification, licensed from UNH, developed by Luciano Fonseca)

● GeoCoder is a software application and include algorithms and interface for visualization and analysis

● Bottom classification through the application of AVO (Amplitude versus Offset) - Variation of acoustic backscatter with the angle of incidence is a an intrinsic property of the seafloor.


● Backscatter is corrected for radiometric and

geometric distortions

Gain, power, pulse width, Beam pattern etc…

● Objective is to determine parameters for the

backscatter inversion model


Acoustic model

Interface backscatter

Volume backscatter

of incidence is a an intrinsic property of the seafloor.

Bottom Classification GeoCoder examples

● Integrated approach

● Loading of backscatter, navigation and bathymetry data in GeoCoder directly from PDS2000 Log files

● PDS2000 executes the steps normally performed by GeoCoder user interface

● Write data to a PDS2000 Grid model● Backscatter mosaic

● AVO parameters

● Seafloor properties

● Bottom types


Detection of Sunken Heavy Oil

Document pathwww.reson.comSECURITY DESIGNATION

Detection of Sunken Heavy OilOil Spill Statistics & reason for USCG Study

● Analysts for the Oil Spill Intelligence Report, reported that spills greater than 10,000 gallons (34 tons) have occurred in the waters of 112 nations since 1960. But they also reported (Etkin 1997) that oil spills happen more frequently in certain parts of the world.

● No efficient solutions for detection of heavy fuel oil on seabed exists

● Sunken Oil is a source of pollution that is of significant detriment to the environment


● US Coast Guard’s Research and Development Center (USCG RDC) identified remote detection and monitoring of sunken oil as one of the key targets for further government funded research

Requirements:Wide area surveillance & identification

Localized positive identification of oil

● The USCG RDC awarded RESON, Inc. a contract to supply a Proof of Concept to detect heavy oil on the sea floor along with partners:

Flemming Hvidbak of FlemmingCo environmental and oil spill professional with 24 years of experience within the oil spill industry

University of New Hampshire: Center for Coastal & Ocean Mapping Joint Hydrographic Center (UNH:CCOM JHC), Project scientist: Dr. Luciano Fonseca

Detection of Sunken Heavy Oil Sidescan & Snippets Imagery Outputs

● Sidescan and Snippets (aka seafloor backscatter) both provide imagery of the seafloor however, due to the fact that Snippets provides backscatter/ amplitude for each footprint (versus average of each side), the detail is much more pronounced.

● The result are mosaics that are easily overlain with digital terrain models (bottom) that provide invaluable information of seafloor


invaluable information of seafloor substrate and morphology.

300 300Snippets Sample Window Size

Bottom Detect

Detection of Sunken Heavy Oil DTM with Snippets Overlay

Rock Reef Sand Waves with Gravel Troughs


Snippets Acoustic Backscatter Provides a quantitative method to identify different

substrates based upon their acoustic “reflectivity”. The harder returns (i.e. Rock) in

this image are dark grey while the softer returns (i.e. sand/silt) are light grey.

Detection of Sunken Heavy Oil Acoustic Detection Principle

● The detection algorithm has used the fact that the backscattered acoustic field depends on the angle between the incoming field and the seabed

● This angular response is different for different types of sediment


Amplitude Snippet data over one beam footprint.

Detection of Sunken Heavy Oil Test Facility

● Prototype test performed at Ohmsett test facility in New Jersey.

● Ohmsett’s above ground concrete test tank is one of the largest of its kind, measuring 203 meters long by 20 meters wide by 3.4 meters deep.

● The tank is filled with 2.6 million gallons of saltwater.


Detection of Sunken Heavy Oil Test setup

2

An area of size 40 ft x 40 ft was applied with

10 trays of size 8 ft x20 ft.

Oil types used in the test: Oil #6, Tesoro, Sundex and asphalt


2 4 6 8 10 12

4

6

8

10

12

Sketch of the entire test area for the Prototype

Demonstration Test at OHMSETT 2009

Photo of trays on bottom of test tank

Detection of Sunken Heavy Oil Results

Detected area is calculated

and compared to the Actual

(according to USCG sketch)

Detection rate /Oil Oil

Λ Γ 91%

False alarm rate /NoOil Tot

Λ Λ 20%

If the OHMSETT test detection-processing time is transferred to a 1 square mile survey at 30m


processing time is transferred to a 1 square mile survey at 30m depth the processing time will be about 12 hours.

RESON’s Solution is accepted and now endorsed by the US Coast Guard

Operational scenarios include use with Bathymetric MBES system located on surface vessel or ROV

Waterside Security (WSS)

Operational requirements:

● Detect combat swimmers

● Localize and track

● Illuminate entire surveillance area with each

ping

● Track long enough to distinguish between

marine life and threat


Harbor Protection

Automatic Detection & Tracking (ADT)

● Applied on all FLS

● Analyzes sonar echo sequence and

suppresses static background

● Automatically detects and tracks moving

targets

WSS VideoSeaBat 7112


NATO HPT2008 Trials - Germany

Leakage Detection


Leakage Detectionfor subsea environments


Introduction

● RESON has developed a technology concept for the detection of leaks from the vicinity of subsea templates and structures

● Leaks include hydrocarbons (gas or liquid), hydraulic fluids and other pollutants

● Based on SeaBat sonar technology and includes automated detection algorithms intended to be used in fixed long term subsea installations


Basic principle:

Sonar ‘ping’ transmits energy into water

Leak media reflects energy based on

Acoustic Reflection properties

Leakage DetectionAre there other options?

Leakage Detection technologies:

● Chemical sniffers

point sensors, can’t cover an area

positive ID of leak substance possible

● Video cameras: limited range in turbid water

● Passive acoustics (hydrophones only):

leak has to make a significant level of noise


Sensitive to environmental background noise

Advantages of SeaBat (sonar) technology:

● Detection of leaks not emitting noise by use of acoustic backscatter

● Wide area coverage

● Able to detect various leak media (gas, oil, MEG etc.)

● Sonars are also passive – sonars can also detect leak noise in similar manner

to hydrophones


Post processing of data collected at SINTEF

RESON participated in an evaluation of Leak Detection technologies at SINTEF, Scandinavia’s largest research institute.

● A number of leak scenarios were tested and various equipment from chemical sniffers to video technology were put to the test

Below: 10bar crude oil leak through 0.7mm nozzle – not easy to see in raw data, tank in a nasty acoustic environment

The improvement from processing of the raw data is obvious

The tank was small, so only short range tests were possible


The tank was small, so only short range tests were possible

RESON follow up testing at long rangeKorsør Naval Harbor

Air

Leak

6bar

(6m range)


Air

Leak

2bar

(28m

range)

Only air gas leaks were possible sue

to environmental concerns

‘Real life’ operations - offshore leak detection from ROV


Some interesting data was gathered (videos follow) and the system was able to find

the leak


The site of the big leak


As the majority here are hydrographers I’ll conclude with an interesting bathymetric image

There are many new and exciting applications for multi beam echo sounder technology and RESON is at the forefront for new application development

Technology

Simon Barchard, RESON