Underwater vehicle networks for acoustic and oceanographic measurements in littoral ocean

The GOATS Joint Research Project(Generic Oceanographic Array Technology Systems)

1998 - 2001

AUV based REA and MCM

Insufficient capability to

Do covert reconnaissance in VSWOperate in all water depths Counter modern mines at safe distanceOperate quickly ahead of amphibious forcesCollect & disseminate environmental data

REA and MCM with a suite of AUV based sensorsReduced risk to personnelCovert operations Faster operations (multiple systems)Reduced cost

GOATS Original Objectives - 1 Demonstrate REA techniques for mine warfare using AUVs,

including the acquisition of ocean parameters in a test area North of Elba Island, and the subsequent data fusion in a geographically referenced data base distributed over a wireless network, available for browsing at remote REA sites.

Use nested oceanographic models to predict the effect of wind waves and currents on AUV performance especially in very shallow water

Develop and validate 3-D acoustic modeling capabilities for target scattering and reverberation in shallow and very shallow water

GOATS Original Objectives - 2 Investigate feature based navigation (FBN) and bathymetric

navigation (BN) techniques applicable to AUV with the final goal to demonstrate concurrent mapping and localization (CML) capabilities

Develop the preliminary on-board logic to detect and classify mines from an AUV adapting search patterns and strategies to water depth, marine growths, bottom types and characteristics of the detected objects

Demonstrate the autonomous, adaptive detection and acquisition of 3-D multipath features of acoustic target scattering

GOATS plan of action & milestones

GOATS’98 Experiment

HLA Data

Flush-buried Cylinder - 45 deg Aspect

GOATS’98 Model validation and measurement of target scattering

OASES-3D Modeling

1m diameter air-filled sphere buried 1m deep from centre

Frequency & grazing angle dependence for buried sphere

GOATS’00 Multiscale Environmental Assessment Network Studies (MEANS)

SWAFSBASIN SCALE

MODEL(10 km)

CUPOMREGIONAL

MODEL(3.3 km)

HOPSREGIONAL

MODEL(1 km)

HOPSLOCALMODEL(0.3 km)

SEPTR

TAIPAN

GOATS’00 MEANS Results

Successfully issued 11 sets of model forecast products for three modeling domains in real time over the web

Comparison with sea surface temperature and ADCP data show that model results accurately forecast local conditions

Procchio Bay circulation was forecast by assimilating into dynamical model only data external to the Bay

1st ever nesting of HOPS and CUPOM

GOATS’00 REA experiment

OEX

OEX equipped with DF1000 and Video provided tiled SSS and unsupervised segmented images of Procchio Bay

GOATS’00 Bistatic scattering

Odyssey

TOPAS tower

Water filled sphere

Water filled cylinder

GOATS’00Bistatic Scattering Enhancement Demonstrated with AUV

TargetBearing

Cylinder

Direct

Cylinder

Direct

BistaticConfiguration

MonostaticConfiguration

Initial demonstration of cooperative behaviour

GOATS’00Adaptive behaviour and multi aspect classification

OEX

Manta MP80 Rockan

GOATS’00 Bathymetric Navigation

The TRIN algorithm developed by FFI has been tested on real data from GOATS 2000:

It is stable and insensitive to errors in initial position in this type of bathymetry. It needs only a few beams, and runs in real time.

GOATS 99 and 00 Networked GIS database

Final results - 1 AUV networks can be operated in very shallow, denied littoral areas, launched

from off-shore platforms, and operated either fully autonomous or under partial remote control to perform MCM and REA missions

AUV networks feasible as generic platforms for environmentally adaptive sonar technology

Current wave-theory models capable of accurate prediction of target scattering and reverberation in littoral environments

Oceanographic models with different resolution can be nested to forecast current fields and help planning AUV missions in littoral environment

Terrain referenced navigation can provide sufficient accuracy to navigate AUVs

Networked GIS DB are efficient tools to distribute REA information

Final results - 2 Very successful interdisciplinary, multinational Joint Research Project

covering Oceanography, REA and MCM, spanning from basic research (bistatic sonar) to prototype development (Networked GIS and video DB)

Successful demonstration of the Virtual Laboratory Concept Unique data set that has generated many joint scientific publications :

9 refereed journal articles, 12 papers in conference proceedings, 2 SLC reports

The international cooperation of the JRP enabled SLC to quickly bridge the gap on AUV technology developed over the years

SLC is the ideal place to develop a comprehensive AUV program as proposed by the MO2015 report (MCM Concept Development and Experimentation)

Future plans

• Improve performance of single AUV– Advanced minehunting sonars for AUVs (SAS, Bathymetric)– Navigation

• SAS micronavigation• Terrain referenced navigation and CML

– Adaptive behaviours• Multi aspect detection and classification• Optimal mission execution (oceanography, sea floor)

• Improve performance of a network of AUVs– cooperative behaviours– integrated communication and navigation– networked GIS data base

• Assess the value of battle space preparation with AUVs

P01B schedule

MEANS-ASCOT’02

MCMFORMED PC trial