Using A Fleet of Slocum Battery Glidersin a Regional Scale Coastal Ocean Observatory

Elizabeth L. Creed, Chhaya Mudgal, Scott M. Glenn and Oscar M. SchofieldRutgers, The State University of New JerseyNew Brunswick, NJ 08901

Clayton P. Jones and Douglas C. WebbWebb Research CorporationFalmouth, MA 02536

Webb Research Corporation

Development of Slocum Gliders Funded By:

Office of Naval Research

State of New Jersey

National Ocean Partnership Program

NOAA National Undersea Research Program

National Science Foundation

Length: 1.5 mWeight: 52 kg

Hull Diameter: 21.3 cm

Slocum Electric Glider

Slocum Electric Glider

Slocum Electric Glider

Slocum Electric Glider Communication

Iridium Antenna

ARGOS and FreeWave Antennas

Glider Communication

Communication between the Glider and the Shore Command Center can be done in three ways:

1) FreeWave modems for local, high speed communication

Line of Sight RF (928MHz)

2) ARGOS as a recovery beacon

3) Iridium for bi-directional, long distance communications

Glider Operation

Moves in a saw-toothed trajectory

Forward speed of 1 knot

Depth range 4-200 meters

Navigation done using GPS, dead reckoning and the altimeter

Average deployment duration is 30 days and 1500 km

Jettison Weight

Glider Abort Mechanism

Slocum Electric Glider

Hydroscat 2 Mounted In Glider Science Bay

Hydroscat 2 and CTD Mounted in Glider Science Bay

Hydroscat 2

CTD

Controlling the Gliders

A Mission Control Center is under constructionto guide the fleet of Gliders in their data collection

The goal of the Center is to develop a flexibleautonomous and responsive tool to coordinate themissions of the Glider Fleet

This goal will be accomplished by the Centerusing data transmitted to it from:

1) The Glider Fleet

2) Other scientific systems - CODARSSTs, SeaWifs

Controlling the Glider

A Mission is defined as a set of scientific instructionsthat tell the Glider(s) where and how to sample

The Mission can track vertical features such asthermoclines or horizontal features such asfronts

Implementation of the Mission Control Center is based onAgent Oriented Programming

Deals with the construction of software agentswhich are entities that behave rationally, havedecision making capabilities and act on behalf ofthe user - each data source has an agent

Decisions are made using an influence diagram

Mission Control Center

2 branches of the Center

1) Decision making

2) Data visualization and Glider tracking

Glider Control Software Flow Chart

Temperature Data July 2000

Temperature (C)

Dep

th (

m)

Dep

th (

m)

Temperature Comparison

Salinity (psu)

Salinity Comparison

July 2000

Along-Shore Average Velocity Component of Glider and ADCP

Cross-Shore Average Velocity Component of Glider and ADCP

July 2000

Hydroscat 2 Optical BackscatterTransect 2, August 2002

Slocum Glider Simulator TrackOctober 22, 2002

Future Plans

Software: The agent software will become part of theGlider’s on-board computer

Field Work: Long-term Glider tests are planned for theNew York Bight Apex to observe the interaction of the Hudson River plume withthe stratified continental shelf waters

Instrumentation: 1) Miniaturization and installation of a hyperspectral spectrophotometer2) Installation of a hockey puck sized absorption and attenuation meter

Conclusions

Gliders will provide scientists with continuous andspatially extensive data

Independent of ship and personnel availability

Independent of weather

Rutgers University

Coastal Ocean Observatory Lab Website

http://marine.rutgers.edu/cool

Glider Testing Center