Space photographs as remote sensing data for reef environments Julie A. Robinson Office of Earth...

Space photographs as remote Space photographs as remote sensing data for reef sensing data for reef

environmentsenvironments

Julie A. RobinsonJulie A. RobinsonOffice of Earth Sciences, NASA Johnson Space Center

Lockheed Martin Space Operationsjarobins@ems.jsc.nasa.gov

ObjectivesObjectives

Provide information about space photography as Provide information about space photography as a data sourcea data source– pros and conspros and cons– accessibilityaccessibility

Show example of collaboration with ReefBaseShow example of collaboration with ReefBase Show potential for quantitative remote sensing Show potential for quantitative remote sensing

applicationsapplications Look ahead to Space StationLook ahead to Space Station

Remote sensing dataRemote sensing data

Image Type Price / scene Pixel sizeNOAA AVHRR $50-90 1 km

Landsat MSS $200-1000 80 m

Landsat TM $425-4400 30 m

SPOT $1800-3000 10-20 m

Aerial photos $20-40 + flight < 1 - 15 m

Space photos $0-25 variable

Advantages of space photography over Advantages of space photography over other remote sensing dataother remote sensing data

Low costLow cost Resolution can equal or exceed SPOTResolution can equal or exceed SPOT Can be combined with other data and maps Can be combined with other data and maps

using existing image analysis and GIS using existing image analysis and GIS softwaresoftware

Image size (Mb) small, transfer via internetImage size (Mb) small, transfer via internet Long time seriesLong time series Search tools on WWWSearch tools on WWW

Cons: Space photos are more variable Cons: Space photos are more variable than data from robotic satellitesthan data from robotic satellites

ResolutionResolution VignettingVignetting Exposure and IlluminationExposure and Illumination Coverage areasCoverage areas Cloud obstructionCloud obstruction Look anglesLook angles Usually needs to be digitizedUsually needs to be digitized

Maximum possible digital resolution (minimum pixel Maximum possible digital resolution (minimum pixel size in size in mm) for hand-held photographs scanned at ) for hand-held photographs scanned at

2400 ppi.2400 ppi.

AltitudeMinimum Median Maximum

Camera Lens 222 km 326 km 611 km

Linhof 90 mm 26.1 38.3 71.8

250 mm 9.4 13.8 25.9

Hasselblad 100 mm 23.5 34.5 64.7

250 mm 9.4 13.8 25.9

Nikon 300 mm 7.8 11.5 21.6

400 mm 5.9 8.62 16.2

Variable illuminationVariable illumination

International Space StationDaylight tracks for 16 consecutive orbits (about one

day), 51.6 ° inclination, 173 naut. mi.

Low Oblique High ObliqueNear Vertical

All taken from 200 naut. mi. with 100 mm lens

Web AccessWeb Access Office of Earth SciencesOffice of Earth Sciences http://eol.jsc.nasa.govhttp://eol.jsc.nasa.gov

– Search tools: clickable map, key words, 350,000 + Search tools: clickable map, key words, 350,000 + recordsrecords

– Browse imagesBrowse images

– Background information and reportsBackground information and reports

– How to order photosHow to order photos Earth from Space Earth from Space http://earth.jsc.nasa.govhttp://earth.jsc.nasa.gov

– Information for the general publicInformation for the general public

– Outstanding photographs with captions that can be Outstanding photographs with captions that can be downloaded in high resolutiondownloaded in high resolution

– Kodak on-line printing serviceKodak on-line printing service

ReefBase CollaborationReefBase Collaboration

Marco NoordeloosMarco Noordeloos

ICLARMICLARM

ReefBase CollaborationReefBase Collaboration

Sharing photosSharing photos

ReefBase CollaborationReefBase Collaboration

Sharing photosSharing photos GIS Base MapsGIS Base Maps

STS068-258-42

STS055-82-67

STS055-82-67

STS059-227-42

ReefBase CollaborationReefBase Collaboration

Sharing photosSharing photos GIS Base MapsGIS Base Maps ““Missing Reefs”Missing Reefs”

– Shuttle/ Station targetsShuttle/ Station targets Coarse-scale global Coarse-scale global

surveysurvey More???More???

Examples of marine remote Examples of marine remote sensing using space photossensing using space photos

Mangrove and coastal land use classificationMangrove and coastal land use classification

Edward L. Webb, Ma. Arlene Evangelista Edward L. Webb, Ma. Arlene Evangelista

Asian Institute of TechnologyAsian Institute of Technology

Seagrass classificationSeagrass classification

Warren Lee Long and Len McKenzie, Warren Lee Long and Len McKenzie, Queensland Dept. Primary IndustriesQueensland Dept. Primary Industries

Coastal land use and mangroves--Coastal land use and mangroves--MethodsMethods

Chanthaburi province, eastern ThailandChanthaburi province, eastern Thailand Land cover: rice fields, shrimp farms, orchards, Land cover: rice fields, shrimp farms, orchards,

degraded mangrove patchesdegraded mangrove patches Digitized RGB Shuttle photo, georeferenced to Digitized RGB Shuttle photo, georeferenced to

1:50,000 topo map1:50,000 topo map Landsat TM imageLandsat TM image A priori supervised classificationA priori supervised classification Ground truth with 45 sitesGround truth with 45 sites

Coastal land use and mangroves--Coastal land use and mangroves--ResultsResults

Space photo pixel size = 10.5 m after resamplingSpace photo pixel size = 10.5 m after resampling Mean consistency (overlap between the Mean consistency (overlap between the a prioria priori

and corrected image) was not significantly and corrected image) was not significantly different between EOP and Landsatdifferent between EOP and Landsat

High variability in land use classification High variability in land use classification consistency between photo and Landsat for consistency between photo and Landsat for a a prioripriori classifications classifications– Ground-truth improved the consistencyGround-truth improved the consistency– Differences were at the edges of polygonsDifferences were at the edges of polygons

Seagrasses--MethodsSeagrasses--Methods

Shoalwater Bay, QueenslandShoalwater Bay, Queensland General survey map from video RS with diving General survey map from video RS with diving

ground truthground truth Digitized RGB Shuttle photo, georeferenced to Digitized RGB Shuttle photo, georeferenced to

survey mapsurvey map Supervised classificationSupervised classification

Seagrasses--ResultsSeagrasses--Results

Pixel size ~58 m in the cropped imagePixel size ~58 m in the cropped image Remarkable classification performance for the Remarkable classification performance for the

coarse scale of this pilot studycoarse scale of this pilot study Confusion of mangroves and forestConfusion of mangroves and forest

– can be reduced with shoreline filtercan be reduced with shoreline filter Confusion of seagrass and mud/sedimentsConfusion of seagrass and mud/sediments

– need to apply species-specific information and need to apply species-specific information and exclude sparsely-growing seagrassesexclude sparsely-growing seagrasses

Next step: full GISNext step: full GIS

ConclusionsConclusions

Space photography can be used as digital Space photography can be used as digital remote sensing dataremote sensing data– studying and monitoring land use changestudying and monitoring land use change– incorporation into existing GIS systemsincorporation into existing GIS systems

This is particularly appropriate in cases This is particularly appropriate in cases where cost is an important factorwhere cost is an important factor– low budgetlow budget– high number of imageshigh number of images– regional scaleregional scale

International Space StationInternational Space Station(ISS)(ISS)

Window Observational Research Facility Window Observational Research Facility (WORF)(WORF)

Optical quality, fused quartz windowOptical quality, fused quartz window– transmissivity, interference, etc.transmissivity, interference, etc.

Removable scratch paneRemovable scratch pane Rack system with cooling, power, etc.Rack system with cooling, power, etc. Payload and “Earth Obs” mode of data collectionPayload and “Earth Obs” mode of data collection

– film, ESCfilm, ESC– multispectral and hyperspectral sensorsmultispectral and hyperspectral sensors

My view of reef opportunities My view of reef opportunities on ISSon ISS

Filling in “missing reefs” during long-duration Filling in “missing reefs” during long-duration missions (photographic)missions (photographic)

New and better instruments for the “techies”New and better instruments for the “techies”– satellite developmentsatellite development– as as thethe data collection platform data collection platform– hyperspectral sensors developed for aircrafthyperspectral sensors developed for aircraft

Opportunity for reef-directed payloadOpportunity for reef-directed payload

ConclusionsConclusions

When all you have is a hammer, When all you have is a hammer, every problem looks like a every problem looks like a nail.nail.

ANDAND

Don’t use a baseball bat to swat Don’t use a baseball bat to swat flies.flies.