Ship Detection High Res Satellite Imagery

7/24/2019 Ship Detection High Res Satellite Imagery

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SHIP DETECTION USING HIGHRESOLUTION

SATELLITE IMAGERY ANDSPACEBASED AIS

TonjeNanetteHannevik

NorwegianDefence ResearchEst.(FFI)


2/27

Outline AIS

AISSat

1 Radarsatellites

SARandAIS

TheMalangentrial Results

Tracking examples

Conclusions


3/27

Introduction Increased shippingandfishing along the Norwegiancoast and

inthe BarentsSea

Spaceborne SARsince 1998 increase overview

Traditionally:Coarse resolution SARimagery

Recently:

Space

based AIS

>

Higher resolution SAR

data

for

selected areasof interest

SAR:RADARSAT2,TerraSARX,CosmoSkyMed

Optical:

Worldview

1

and

GeoEye Presentation:

Ship detection inhigh resolution imagery

Combined with spacebased andlandbased AIS


4/27

AIS Anticollision system shipboard transponders

Passenger ships,

cargo

ships over

300

gross

tons,

fishingvessels >45m

Ships position,speed,heading,load,size andship type++

Land

based AIS:

range

40

nautical miles Satellitebased AIS:increases rangetremendously to

monitorNorways vastocean areasinthe HighNorth

VHF

VHF

VHF


5/27

Spaceborne AIS FFIlaunched AISSat1with AIStransponderJuly12th2010

Receive AIS

signals

in

space Demonstration mission:vessel detection inwatersnorth of

ArcticCircle


6/27

Radarsatellites inorbit Increasing number of SARsensors

In

orbit: RADARSAT1andRADARSAT2

TerraSARX,TandemX

COSMO

SkyMed 1,

2,

3

and

4Military systems


7/27

Planned radarsatellitesSentinel1AandSentinel1B

RADARSATConstellationMission

Military systems


8/27

RADARSAT2 Launched December 2007

New

opportunities for

spaceborne monitoring of vesseltraffic andfishing activities

Betterresolution

Flexible look direction

Multiplepolarisation options

Quadpolarisation data:4imagesof sameareaindiff.pol.


9/27

SARandAIS Complimentary

Combinationof AISandSARforsurveillance inremote

areas

AIS:identify vessels detected inSARimages

SAR:detect vessels notreporting through AIS

shipinfo.com


10/27

Malangentrialanddatacollection Malangen:goodtestsite

Possiblewithmultipleobservationsofsameship

AISdatafromlandbasedandspacebasedAIS

September2010

Data:

4RADARSAT2StandardQuadPolimages

LandbasedAIS(aisonline.com)

SpacebasedAIS(AISSat1)

Time

# Date SAR aisonline AISSat-1

1 19/9 16:31 16:30 & 16:35 16:31 - 16:45

2 21/9 15:33 15:35 15:35 - 15:48

3 23/9 16:14 16:15 16:13 - 16:27

4 29/9 16:39 16:40 16:34 - 16:48


11/27

September19th SAR:16:31

Aisonline.com:16:30&16:35

AISSat1:16:31 16:45

Detections September 19th

Ship SAR aisonline

AISSat-1

Class,

detected?1 Detected OK B, detected

2 Detected OK A, detected

3 Detected OK A, detected

4 Detected OK B, -

5 Detected OK A, -

6 Detected OK A, -

7 Detected OK A, -

8 Detected OK A, -

9 Land OK B, detected

10 Land OK B, -


12/27

September29th SAR:16:39

Aisonline.com:16:40

AISSat1:16:34 16:48

Detections September 29th

Ship SAR aisonline

AISSat-1

Class, detected?

1 Detected OK B, detected 4

times at 08:37

2 Detected OK A, detected 3times between

07:00-07:02

3 Detected OK B, detected 2

times at 16:45

4 Land, detected OK B, -

Whiteandgreen:AISSat1

Black:

SAR


13/27

Tracking ships AISSat1:new opportunity totrack ships notwithin the 40

nautical miles rangeof the landbased AIS

Example 1:Muddr080detected using SARSeptember19th and

23rd

ShipdetectedseveraltimesfromAISSat1


14/27

Muddr080 Detected 35timesbyAISSat1between 17/912:45and

23/9

19:38 in

2010


15/27

Quadpolarised data signatures oftracked ship high incidence angle

VH

HH

VV

HV


16/27

Ships,landandsea SAR2DimageandSAR3Damplitudeimage

Tracked ship

Tracked ship


17/27

Tracking of VladimirTikhonov24/1110to18/612


18/27

Tracking of VladimirThikanov NorthEastPassage:20/811to7/911


19/27

Discussion missed detections AISSat1passesfromsouth >saturation NorthSea/BalticSea

Signalsarrivingattheantennaatthesametime(messagecoll.) Butpartofpassshouldbeunaffected


20/27

Received messages19/9/2010 Achieved performance

no messages received forthe first89minutes

Effective passduration reduced from15min.to67min.

0

0.05

0.1

0.15

0.2

0.25

0.3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Percentageofall

messagesreceived

Minutesintopass

PercentageofallreceivedmessagesbyAISSat1asa

functionoftimeintothepassat16:3016:46


21/27

Simulated results forsimilar passgeometry Discrepancy notalone because of:

Noships inthe areainthe beginning (lastslide9/19)

Large#of ships inNorthSeaandBaltic

0

0.02

0.04

0.06

0.080.1

0.12

0.14

0.16

0.18

0.2

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 More

Percentageofallreceivedmessages

Minutesintopass

PercentageofallreceivedmessagesbyAISSat1

insimulationasafunctionoftimeintothepass

at16:2216:38 6/8/2011


22/27

Discussions missed detections Relationship between incr.performance anddecr.landarea

Malangenareaclose toland

Interference fromlandbased reuse of AISfrequencies 1and2that are alsousedon AISSat1

Signalcollisions prob.of det.decreases

Fjords

around Troms

elevation angle

small in

beginning of pass Nolineof sight duetohigh mountains (beg.andendof pass) further

reducing the effective passduration

HighmountainsmakesshadowsforAISSat1inMalangen area


23/27

Discussion missed detections Vulnerableforreducedeffectivepassduration:

ClassBshipssendAISsignalsusinglowerpowerandlessfrequent

thanClassAships

Shipsatporttransmitsmessagesatalowerrate >harderto

detectfromspaceduetolowertransmitrate&limitedtimein

satellitesfieldofview

AISequipment notinstalled properly onboard ships


24/27

Conclusions sumof challenges Detectionprobabilityinasinglepassvariesconsiderably

Eveninalowtrafficarea(closetoland!)suchasthe

northofNorway AISSat1performancevarieswiththesatelliteantenna

pointingconfiguration

AISSat

1 still

in

its

commissioning

phase

(during

trial)

Noactiveantennacontrol

Nowantennacontrolispossible betterperformanceinfuturetrials

Overtime:shipdetectionprobabilityincreasesgreatly

tracking SpacebasedAIShaslargerprobabilitytodetectshipsinthe

openoceanareasthanclosetothecoast


25/27

Conclusions Ships reported byaisonline.comare detected inSARimages

(except ships close tolandorvery small ships


26/27

NORAIS,AISSat2andAISSat3 NORAIS

Now on InternationalSpaceStation

AISSat2

Identical designasAISSat1

Flightmodel isfinished

Environmental testswill bedone

Increased coverage andbackup

Launch 3rdor4thquarterof 2013?

AISSat3 Betterreceiver

Next generation AISsatellite

Another payload aswell on the satellite?


27/27

Aknowledgements AISdata courtesyofNorwegianCoastal

Administration:aisonline.comoperatedbyChristianMichelsenResearch(CMR)

ThankstotheNorwegianSpaceCentrefor

sponsoringAISSat1

Documents

Ship Detection High Res Satellite Imagery