Making UAVSAR Data More Accessible - University of Alaska

Making UAVSAR Data More AccessibleLessons from PolSAR ClassificationIn Arctic AlaskaDon AtwoodGeophysical InstituteUniversity of Alaska FairbanksBruce Chapman and Scott HensleyCEOS Meeting - Nov 7-9, 2011Don AtwoodNASA Jet Propulsion Lab

Presentation Overview• Introduce UAVSAR and Current Data Products• UAVSAR processing issues associated with PolSAR Classification• Need for “Entry-level” visualization• Handling Data Volume – Need for Multilooking• Role of Radiometric Normalization• Dealing with Ellipsoidal and Local Incidence Angles• Summary of Value-added Products and Final RemarksCEOS Meeting - Nov 7-9, 2011Don Atwood

Current SAR StatusERS-2 RADARSAT-1 ENVISAT ALOS PALSAR RADARSAT-2 TanDEM-XCOSMO-SkyMedBand C-band C-band C-band L-band C-band X-band X-bandPolarization VV HHHH/VV, HH/HV,VV/VHQuad/Dual/SingleQuad/Dual/SingleQuad/Dual/SingleSelectableLaunch Date 1995 1995 2002 2006 2007 2007 2007Swath 100 km 50-460 km 100-400 km 70-350 km 20-500 km 5-100 km 10-200 kmResolution 30m 10-30m 30-150m 10-100m 3-100m 1-16m 1-100mRepeat Cycle 35 days 24 days 35 days 46 days 24 days 11 days ConstellationCEOS Meeting - Nov 7-9, 2011Don Atwood

UAVSARNASA Jet Propulsion Lab’s UAVSAR Instrument• Reconfigurable L-band, quad-polarimetric SAR• Developed specifically for repeat track differential interferometry• Designed to be flown aboard a UAV (Unmanned Aerial Vehicle)• Currently being flown aboard a Gulfstream III• Mission-based data acquisitionCEOS Meeting - Nov 7-9, 2011Don Atwood

UAVSARNASA Jet Propulsion Lab’s UAVSAR Instrument• Reconfigurable L-band, quad-polarimetric SAR• Developed specifically for repeat track differential interferometry• Designed to be flown aboard a UAV (Uninhabited Aerial Vehicle)• Currently being flown aboard a Gulfstream III• Mission-based data acquisition• Lacks coverage of spaceborne SAR, but offers higher resolution(than many) and better noise floor• Rich diversity of datasets exist in the archiveCEOS Meeting - Nov 7-9, 2011Don Atwood

UAVSAR Data• More than 100 missions in theWestern Hemisphere• Disciplines span:• Glaciology• Forestry• Hydrology• Volcanology• Oceanography• Land Cover• Earthquakes• Oil Spills• Lost AircraftCEOS Meeting - Nov 7-9, 2011Don Atwood

Current Data HoldingsCEOS Meeting - Nov 7-9, 2011Don Atwood

Current Data HoldingsCEOS Meeting - Nov 7-9, 2011Don Atwood

Current Data HoldingsCEOS Meeting - Nov 7-9, 2011Don Atwood

Current Data HoldingsCEOS Meeting - Nov 7-9, 2011Don Atwood

Getting DataAlaska Satellite FacilityUAVSAR as Unrestricted Dataset – Instant Downloadhttp://www.asf.alaska.edu/CEOS Meeting - Nov 7-9, 2011Don Atwood

UAVSAR InSAR ProductsFirst earthquake deformation captured by the UAVSAR system, using data acquiredon October 21, 2009 and April 13, 2010CEOS Meeting - Nov 7-9, 2011Don Atwood

UAVSAR PolSAR ProductsJPL Polarimetric SAR Products:• Covariance matrix elements (GRD binary files)• Fully terrain corrected• Three real, three complex• Covariance matrix elements (MLC binary files)• Three real, three complex• Annotation file for metadata• Digital Elevation Model (DEM)• GIF image (HH, HV, VV)• KMZ file• Stokes MatrixCEOS Meeting - Nov 7-9, 2011Don Atwood

Classification ProcedureGenerate Multilooked C3 Perform Wishart Convert to GeoTIFFRadiometric Correction Unsupervised Export to GISPOA Compensation Classification Assign ClassesCEOS Meeting - Nov 7-9, 2011Don Atwood

Classificationof Florida EvergladesYamaguchi Decomposition Wishart Segmentation Land Cover ClassificationCEOS Meeting - Nov 7-9, 2011Don Atwood

Classification ResultsUSGS NLCD 2006PolSAR ClassificationCEOS Meeting - Nov 7-9, 2011Don Atwood

Visualization Products500 x 800 GIF Image in KMZ:HH HV VVPauli Decomposition GeoTIFF:HH-VV HV HH+VVCEOS Meeting - Nov 7-9, 2011Don Atwood

Value-Added ProductsRequirements• Simple GIS-ready decompositions as “point of entry” for UAVSARCEOS Meeting - Nov 7-9, 2011Don Atwood

Land Cover Classificationof Yellowstoneylwstn_26903_10067Aug 10, 2010CEOS Meeting - Nov 7-9, 2011Don Atwood

Resolution EffectsOptical imageWishart5m Resolution~ 2 GB perC3 elementWishart3x3 MultiLook15m resolutionWishart5x5 MultiLook25m resolutionCEOS Meeting - Nov 7-9, 2011Don Atwood

Value-Added ProductsRequirements• Simple GIS-ready decompositions as “point of entry” for UAVSAR• Large data volumes can prove burdensome for PC applications• Need for multilooked data setsCEOS Meeting - Nov 7-9, 2011Don Atwood

Topographic EffectsOptical ImageWishart SegmentationNeed for Radiometric NormalizationCEOS Meeting - Nov 7-9, 2011Don Atwood

Radiometric NormalizationUlander Approach:• angle-based radiometric normalization• operates on Ellipsoidal Sigma nought• corrects for local topographyUlander, L.M.H., 1996. Radiometric slope correction of synthetic-aperture radar images.IEEE Transactions on Geoscience and Remote Sensing, 34(5): 1115 – 1122.CEOS Meeting - Nov 7-9, 2011Don Atwood

Radiometric NormalizationNo Correctionwith Radiometric CorrectionImproving PolSAR Land Cover Classification with Radiometric Correction of Coherency MatrixD.K. Atwood, D. Small, and R. GensSubmission to IEEE JSTARSCEOS Meeting - Nov 7-9, 2011Don Atwood

Classification ResultsALOS AVNIR-2PolSAR ClassificationCEOS Meeting - Nov 7-9, 2011Don Atwood

Value-Added ProductsRequirements• Simple GIS-ready decompositions as “point of entry” for UAVSAR• Large data volumes can prove burdensome for PC applicationsNeed for multilooked data sets• Classifications require accurate radiometric normalizationCEOS Meeting - Nov 7-9, 2011Don Atwood

Implications of anAirborne Platform• Unlike Spaceborne SAR, Airborne SAR exhibits much greater range of lookangles• UAVSAR look angles range from 15 to 65 degrees• Impact is more significant when local topography is consideredQuestion: What is the impact upon the scattering mechanisms forspecific land cover classes ?CEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle VariabilityHillshade DEMCEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle Variability90 degrees0 degreesLocal Incidence AngleCEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle VariabilitySegmentation of Local Incidence AngleCEOS Meeting - Nov 7-9, 2011Don Atwood

Investigating ScatteringMechanisms3x3 Multilooked C3 VanZyl Decomposition Export to GISPOA compensationFind scattering mechanismsfor each land cover classCEOS Meeting - Nov 7-9, 2011Don Atwood

Extracting ScatteringStrengths from Land CoverGIS Procedure:• Normalize VanZyl decomposition components(Surface, Double, Volume) for each resolution cell• Determine Probability Distribution Function of ScatteringStrengths for each Land Cover ClassCEOS Meeting - Nov 7-9, 2011Don Atwood

Extracting ScatteringStrengths from Land CoverDouble BounceVolume ScatteringSurface BounceCEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle AnalysisCEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle AnalysisCEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle AnalysisCEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle AnalysisCEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle AnalysisCEOS Meeting - Nov 7-9, 2011Don Atwood

Incidence Angle AnalysisCEOS Meeting - Nov 7-9, 2011Don Atwood

Evergreen Trend AnalysisSurfaceDouble BounceVolumeCEOS Meeting - Nov 7-9, 2011Don Atwood

Summary ofIncidence Angle Effects• Scattering mechanisms vary as a function of local incidence angle forall classes• Trend is diminishing surface scattering and increasing volume anddouble bounce scattering as incidence angle increases• Effect is most pronounced for smooth surfaces (e.g. barren ground)At current time, no effective means exists for addressing incidenceangle effects (Except Polarization Orientation Angle Compensation)CEOS Meeting - Nov 7-9, 2011Don Atwood

Value-Added ProductsRequirements• Simple GIS-ready decompositions as “point of entry” for UAVSAR• Large data volumes can prove burdensome for PC applicationsNeed for multilooked data sets• Classifications require accurate radiometric normalization• Broad range of ellipsoidal and local incidence angles require attention(Incidence angle maps useful as overlays)CEOS Meeting - Nov 7-9, 2011Don Atwood

Value-Added ProductsRequirements• Simple GIS-ready decompositions as “point of entry” for UAVSAR• Large data volumes can prove burdensome for PC applicationsNeed for multilooked data sets• Classifications require accurate radiometric normalization• Broad range of ellipsoidal and local incidence angles require attention(Incidence angle maps useful as overlays)• Potential exists for performing rigorous calculation of POA, instead ofestimationCEOS Meeting - Nov 7-9, 2011Don Atwood

New Value-Added Products• UAVSAR Flight Lines• Pauli Decomposition (Byte) in GeoTIFF• DEM in GeoTIFF• Zipped binary GRD files in three formats:• 1x1• 3x3• 5x5 MultilookedCEOS Meeting - Nov 7-9, 2011Don Atwood

New Value-Added Products• Ellipsoidal Incidence Angle (degrees)• Local Incidence Angle (degrees)• Local DEM slope in East and North directions• possible computation of POA• Ulander Radiometric Normalization factorCEOS Meeting - Nov 7-9, 2011Don Atwood

Final Remarks• UAVSAR offers many advantages over SAR satellite data• higher resolution, better incidence angles, lower noise floor• UAVSAR well-suited for fundamental PolSAR projects,but currently under-utilized• Trivial to download data from ASF Archive• Mission support available for both:• “NASA-funded” and “Non-NASA investigations with NASA concurrence”CEOS Meeting - Nov 7-9, 2011Don Atwood

Questions?CEOS Meeting - Nov 7-9, 2011Photo Credit: Don AtwoodDon AtwoodDon Atwooddkatwood@alaska.edu(907) 474-7380