underwater sensor [presentation]

7/23/2019 Underwater Sensor [Presentation]

http://slidepdf.com/reader/full/underwater-sensor-presentation 1/18

This material is based upon work supported by Science Foundation Ireland under Grant No. 03/IN3/1361

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITY

Underwater SensorCommunication Systems

Raja Jurdak ([email protected])

Antonio Ruzzelli ([email protected])

Gregory O’Hare ([email protected])





Outline

=Rationale

=

Existing Solutions

=Project overview

=Benefits to Ireland’s marine sector





Why Underwater Sensing Systems

= Marine environment remains largely inaccessible= Marine Sensing Application Opportunities

q Environmental monitoringq Scientific data collectionq Underwater exploration

= Underwater communication identified as an existing gap in currentresearch competencies in Ireland (Sea Change, Feb. 2007)

= Existing monitoring strategiesq Surface buoysq Suspension of probesq Underwater cablesq Satellites

= Gaps in state-of-the-art marine monitoring

q Require sensing at multiple spatial and temporal scalesq Equipment, deployment, and maintenance costq Must not interfere with the ambient environment and human activities

(fishing, shipping, etc..)





Outline

=Rationale

=

Existing Solutions

=Project overview

=Benefits to Ireland’s marine sector





Existing PlatformsBuoys/Probes

= High temporalgranularity

= Low spatial granularityfor Ireland’s 7,500 km

coastline= Cost limited to initial

deployment and periodicmaintenance

= Interfere with ambientenvironment (marinewildlife, fishing,shipping)





Research Vessels

= High spatial granularity

= Low temporal granularity

= High collection cost(equipment, manpower,

logistics, etc…)= Does not interfere with

the environment, asvessel presence is onlytransient in theenvironment





Human Intervention A Recent Example: Tolka River

= Reports by local fishermanin July 2005 on poor qualitydischarge of effluent andfish kill

= Response processq Inspectors on sceneq Collection of water samplesq Laboratory Analysisq Several subsequent visits

= Low spatial granularity=

Low temporal granularity= High personnel cost= Does not interfere with

environment





Underwater SensorCommunication Systems

=Dense network of in-situ sensor nodes in thewater qWireless acoustic communicationq High spatial and temporal granularityq Low transmission power >> Minimal interference

with evironment=Problem: Current acoustic communication

hardware cost is prohibitive>> Develop acoustic communication system

based on generic acoustic hardware(microphones and speakers) that are built-into sensor modules





Underwater Sensor NetworksNovel Features

=Use off-the shelf sensor modules

=Develop software modemsqComplement module acoustic hardware

qEnable modules to communicateunderwater

= Cost-effective underwater sensingqLow cost per node

qNo maintenance costs

qNo personnel costs





A Comparison

Low

High

Low

Low

HumanIntervention

Low

High

High

Low

Satellites

LowHighModerateCost

LowLowHighInterferencewithenvironment

HighLowHighTemporalGranularity

HighHighLowSpatialGranularity

SensorNetworks

ResearchVessels

Buoys/Probes

Platform

Metric





Project OverviewUnderwater Network Architecture

Underwater sensor nodes

Surface Buoy

BroadbandRadioConnection

To Internet

datarepository

Wirelessacoustic

links

Interactive Maps

Query and Download tools

Deploy sensor nodes in bay for environmental monitoring• Dense deployment

• Modules periodically collect environmental data,communicate the data through multi-hop wireless links toaggregation point• Aggregation point forwards data to central server for storageand disseminations





Project OverviewIntegration with Smart Bay

datarepository

Interactive Maps

Query and Download tools

Deploy sensor nodes in bay for environmental monitoring• Dense deployment

• Modules periodically collect environmental data,communicate the data through multi-hop wireless links toaggregation point• Aggregation point forwards data to central server for storageand disseminations

Underwatersensor nodes

Wirelessacousticlinks

Underwatercable

Aggregationpoint





Project OverviewTarget Platform

= Off-the-shelf sensor modules for aircommunications

= Project focusq Develop the software to enable wireless

underwater acoustic communicationthrough generic acoustic hardware♦

Software modem♦ Protocols♦ Applications

= Platform cost/unitq Currently US $80-$200q Expected to drop below $10/unit in next

5 years

= Currently working together with Tyndallto create underwater-ready motes withoptimized features





Project OverviewResearch Challenges

=Software modemq Signal design and processingq SynchronizationqModulation and demodulation

=Communication protocolsq Efficient medium access controlq Effective data routing

= Application

q Support configurable operation= In-the-water testing required at all stages of

the project development





Data Communication

0

20

40

60

80

100

1 3 5 7 9 11 13 15 17

Distance (m)

S y m b o l s R e c e i v e d ( % )

6bps 12bps 24bps 48bps

•Experiments with Tmote Invent

Modules/On-board microphone/On-board speaker inside latex membrane

•Evaluate acoustic communication

capability of software modem+Tmote

hardware

2 4 6 8 10 12

x 104

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8





Symbol Synchronization=

Measurements in the River Dodder q Strong currents

q Wildlife (ducks)

q Vegetation and floating objects

0

5

10

15

20

25

0 3 6 9 12 1 5

distance (m)

s y n c h r o n i z a t i o n s h i f t ( m s e c

)

RiverDodder 7m

15m





Underwater Sensor NetworksSynergy with Marine Sector Development

=Future workq Prototype network deployment

q Communication protocol stack development

q Application development

=Complement existing monitoring systems=Our contribution: underwater

communication and networking with sensormodulesq

Higher spatial and temporal granularityq Flexible and low interference solutionq Unattended in-situ operationq Affordable and easily-deployable





Related Publications

= R. Jurdak, A. G. Ruzzelli, G.M.P. O’Hare, and C. V. Lopes. “Reliable SymbolSynchronization in Acoustic Sensor Networks,” Submitted to IEEE GlobeCom.

March, 2007.= R. Jurdak, P. M. Q. Aguiar, P. Baldi, and C. V. Lopes. “Software Modems for

Underwater Sensor Networks,” To appear at IEEE/OES Oceans’07. Aberdeen,Scotland. June, 2007.

= R. Jurdak, P. M.Q. Aguiar, P. Baldi, and C.V. Lopes. “Software Acoustic

Modems for Underwater Sensor Networks,” Submitted to IEEE Journal onOceanic Engineering. November, 2006.

= R. Jurdak, C.V. Lopes, P. M. Q. Aguiar, and P. Baldi. “A Comparative Analysisand Experimental Study on Wireless Aerial and Underwater AcousticCommunications,” In Proc. IEEE International Conference on DigitalTelecommunications (ICDT). Cap Esterel, France. August, 2006.

= R. Jurdak, C.V. Lopes, and P. Baldi. “Software Acoustic Modems for ShortRange Mote-based Underwater Sensor Networks,” In proc. of IEEE Oceans –

Asia Pacific. Singapore. May, 2006.= R. Jurdak, C. V. Lopes and P. Baldi. “Battery Lifetime Estimation andOptimization for Underwater Sensor Networks” In Sensor Network Operations,published by Wiley-IEEE Press, edited by Shashi Phoha, Thomas F. La Portaand Christopher Griffin. pp. 397-420. ISBN: 0-471-71976-5. May, 2006.

underwater sensor [presentation]

Documents