G01 Carter - GeoTools - NOAA

Lasers in the Rainforest:American SamoaDeveloping High Accuracy Elevation Datain American Samoa with Mobile LidarJamie CarterNOAA Pacific Services Center

Outline• Introduction• Phase I: Feasibility study• Phase II: Data collection• Phase III: Data processing• Phase IV: Tsunami modeling• Conclusion

September 29, 2009• 6:48 a.m. – Magnitude 8.1(M w ) earthquake 120 milesto the Southwest• 7:13 a.m. – Tide gaugedetected 3.14-meter wavein harbor• Three additional waves• 191 casualties• $150 million in damages Source:Source:GordonUSGSYamasakiOFR 2010-1018(NOAA)

Post-Event Data Collection• U.S. Geological Survey(USGS) deployed rapidresponse field teams• Inundation limit dataWater heights exceeded17 metersInundation observed upto 600 meters inland• Sources of uncertaintyIdentification errordGPS error (2.5m at 95percent confidence)Source: USGS

Height Characterization of Inundation• 15,703 points mapped• 95% of points less than orequal to 15 meters abovemean sea level (USGS NED)Source: USGS

VulnerabilityTypeBelow 15mSchools 63%Gas Stations 83%Businesses 69%Churches/Shelters 79%Commercial (canneries) 100%Communications 100%Fire Stations 100%Police 100%Airport 100%Government buildings 89%Hospital 100%Ferry terminal 100%Utilities 100%

Height Characterization of Inundation• Accuracy z of NED isapproximately ±7 meters• Vulnerability recomputedusing confidence boundsType Below 8m Below 15m Below 22mSchools 43% 63% 78%Gas Stations 50% 83% 89%Businesses 41% 69% 79%Churches/Shelters 66% 79% 86%Commercial 100% 100% 100%Communications 60% 100% 100%Fire Stations 100% 100% 100%Police 50% 100% 100%Airport 100% 100% 100%Government buildings 78% 89% 100%Hospital 100% 100% 100%Ferry terminal 100% 100% 100%Utilities 0% 100% 100%

Phase I: Feasibility StudyTerritory of American SamoaClimateLand CoverGeomorphologyReconnaissance Mission

Territory of American Samoa• 170° West, 14° South• Five volcanic islands andtwo distant atolls• Total land area is 76square miles (mi 2 )• 57,291 people (2000Census)• Tutuila makes up 72% ofland mass and has 97% ofthe populationTutuilaAunu’uTauOfu/Olosega

Climate of American Samoa• Average annualtemperature is 79° F• Mean annual rainfall is200 inches, with frequentshowers• Precipitation occurs 300days per year on average• Rainy season runs fromOctober to May• Dry season runs from Juneto September

Land Cover of Tutuila and Aunu‘uClass NameSquareMilesPercent ofTotalImpervious Surface 3.14 5.66%Developed, Open Space 2.86 5.15%Cultivated Crops 1.24 2.24%Pasture/Hay 0.10 0.17%Grassland/Herbaceous 0.34 0.61%Deciduous Forest 0.00 0.00%Evergreen Forest 43.09 77.72%Scrub/Shrub 4.38 7.90%Palustrine Forested Wetland 0.01 0.02%Palustrine Scrub/Shrub Wetland 0.01 0.02%Palustrine Emergent Wetland 0.01 0.02%Estuarine Forested Wetland 0.00 0.00%Estuarine Scrub/Shrub Wetland 0.00 0.00%Estuarine Emergent Wetland 0.00 0.00%Unconsolidated Shore 0.00 0.00%Bare Land 0.27 0.49%Source: NOAA Coastal-Change Analysis Program (C-CAP) 2003

Geomorphology of Tutuila• Eroded summit of a largebasaltic volcano• Drowned coastline andunderdeveloped fringingreefs• 20 miles long by 4 mileswide with peak at 2,142 feet• Steep and narrow valleys• Narrow coastal plains

Reconnaissance Mission• Fa’a SamoaCommunicationsCurfews• Resource assessmentVehiclesEquipment/suppliesCalibration targetsLodgingStorage• Site prioritization withAmerican Samoa DOC

Reconnaissance ReportIdentified Challenges:• Dense ground cover andfoliage along the roads• Dense ground cover andfoliage near buildings• Restricted access near andaround buildings and streams• Steep banks andobstructing shorelinestructures

Final Sites

Phase II: Data CollectionOctober 25 to November 2, 2010Mobile mappingConventional survey

Mobile Mapping SystemOptech Lynx Mobile Mapper• Number of lidar sensors: 2• Cameras: 4 x 5-megapixel• Maximum range: >100 meters• Range precision: ± 8 mm• Absolute accuracy: ± 5 cm• Spatial resolution: 1 cm• Laser measurement rate: 200kilohertz programmable• Returns per laser pulse: 4• Scan field of view: 360 degrees

Mission PlanningSurvey planning performedto evaluate:• Calibration site• Satellite visibility• Route redundancy• Potential data gapsCalibration site

Village Mapping Protocol• Samoan Affairs draftedletter to village councils• Local ASDOC staff selectedfor field support• Village mayors consultedbefore all operations

Mobile Lidar Data Collection• Village scans performedwith support from DOC• Data downloaded daily andchecked for quality andcoverage

Conventional Survey Data Collection• Global Positioning System(GPS) networkProcessed againstContinuously OperatingReference Station (CORS)Ground control for mobilemapping system• Total stationUsed in areas where GPSwas not availablePrimarily focused onslope breaks

Phase III: ProcessingCalibrationClassificationProduct Generation

Mobile Lidar Data

Data Processing• Calibration:Horizontal offsetsGhosting• Classification:Bare earthVegetationBuildingsWaterNoise

Product Generation• Calibrated point cloud• Classified point cloud• Bare-earth surfacesTriangulated irregularnetwork (TIN)Raster digital elevationmodel (DEM)• Contours• Geocoded digital imagery• Metadata

Phase IV: Tsunami ModelingNumerical Grid DevelopmentModeling and Analysis

Numerical Grid Development• NOAA NationalGeophysical Data Center(NGDC)3 arc-second seamlessbathymetry/topography1/3 arc-second seamlessbathymetry/topography1/9 arc-second seamless“community” models• Data quality issuesTopographyNearshore bathymetry

Tsunami ModelingNOAA Center for TsunamiResearch, Pacific MarineEnvironmental Laboratory(PMEL)• Tsunami generation• Tsunami propagation• Tsunami inundationWave arrival timeWave heightInundation extentTumon Bay, GuamTsunamiZoneRoadsMaps and graphics by: Jessie Huart,NOAA Pacific Services Center

ConclusionPros• Mobile platform moreefficient than static• Excellent accuracies inaccessible areas• High-resolution• Rapid acquisitionCons• Data storage• Atmospheric conditions• Vegetation and otherobstructions

AcknowledgementsAmerican Samoa Coastal Management ProgramAmerican Samoa Department of CommerceAmerican Samoa National Park ServiceUnited States Geological SurveyThe Sanborn Map CompanyDean and Isabel HudsonSamoan AffairsThe People of American Samoa

Questions?Jamie.Carter@noaa.gov