remote sensing with a drone
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Remote Sensing with a Drone
Remote Sensing with a Droneuse a drone to to derive surface information
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Remote Sensing
Remote Sensingthe science of obtaining information about objects or areas from a distance
Multispectral ImagingRaDAR (Radio Detection and Ranging)LiDAR (Light Detection and RangingSonAR (Sound Detection and Ranging)Photogrammetry
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Electromagnetic spectrumLight is a wave of alternating electric and magnetic fieldsVisible light used in passive remote sensing
http://chandra.harvard.edu/resources/em_radiation.html
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Passive Remote Sensing
Detect natural energy reflected or emitted from observed scene
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photogrammetryPhoto Light, Gramma draw, Metron measureArt, science, and technology of obtaining precise mathematical measurements and three-dimensional (3D) data from two or more photographsUsed for the creation of most topographic maps since the 1930sHighly detailed tw0-dimensional and three-dimensional measurementsTriangulation provides x, y, z coordinate of intersecting lines
photogrammetryX,Y,Z coordinate pairs can be derived for overlapping photos when camera position is known
http://www.clemson.edu/restoration/wlcc/_files/photogrammetry.jpg
Data Collection
Image collection
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Image collection
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Image collection
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Image collection
Images require 80% overlapOblique perspective from image overlapHeight affects resolution & number of imagesSpeed affects image quality JPEG or RAW
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Ground Control POints
Increase Horizontal & Vertical Accuracy by correcting direct georeferencingX, Y, Z coordinate fileIdentifiable in imagesShared by overlapping images Located evenly throughout area of interestCorrect vertical & horizontal position of photos
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Data Processing
Data Processing
Create Spatial DataDrone2Map SoftwareAdvanced Object Detection creating Key Match Points shared by overlapping imagesMosaic overlapping imagesCorrect image X, Y, Z using GCPPhotogrammetry
Georeferenced Overlapping ImagesImage Perspective is Nadir and ObliqueImage matching through advanced object detectionRapid photogrammetric processing and surface detection and ranging15
Products
orthoimageryUniform scale image where corrections have been made for relief displacementShifting pixels towards and away from elevation and principal point
Relief DisplacementCorrected Relief Displacementhttps://www.e-education.psu.edu/natureofgeoinfo/sites/www.e-education.psu.edu.natureofgeoinfo/files/image/keating_left_and_ortho.jpg
Aerial images are not planimetric, they are perspective. Perspective is from principal point, the area directly below camera lens.Goal of Orthorectification is to make the photo consistently planimentric.17
Orthoimagery
18 overlapping (80%) image mosaic - 6,500 matching pointsResolution GSD 3.98cm
: Satellite, Balloon, Aircraft, Boat, Car
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Orthoimagery
18 overlapping (80%) image mosaic - 6,500 matching pointsResolution GSD 3.98cm
: Satellite, Balloon, Aircraft, Boat, Car
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Orthoimagery
18 overlapping (80%) image mosaic - 6,500 matching pointsResolution GSD 3.98cm
: Satellite, Balloon, Aircraft, Boat, Car
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Digital Surface Model
Elevation of natural and antrhopogenic surface
: Satellite, Balloon, Aircraft, Boat, Car
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Digital Surface Model
Elevation (M)
164.70
133.65
fenceconductorsbackstoptrees
: Satellite, Balloon, Aircraft, Boat, Car
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Point cloudSets of X, Y, Z coordinates3d points: 3,231,3513d points per M3: 34.8
Elevation (M)
conductorstreesflood light
: Satellite, Balloon, Aircraft, Boat, Car
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Point cloudSets of X, Y, Z coordinates3d points: 3,231,3513d points per M3: 34.8
Elevation (M)
backstoptreesflood light
: Satellite, Balloon, Aircraft, Boat, Car
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Contours
Slope
Textured Mesh 3d PDFPortable documentGeoreferencedHorizontal and Vertical MeasureDigital markup
: Satellite, Balloon, Aircraft, Boat, Car
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Compare elevation Drone photogrammetry to lidar
Elevation Delta (M)
Area beneath flight is as accurate as LiDAR
Lidar (public available) and PhoDAR are close for flat terrainPhoDAR picked up vegetation and structure not within the lidar point cloud
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Compare elevation Drone photogrammetry to lidar
Elevation Delta (M)
Publicly available LiDAR without overstory returns
Lidar (public available) and PhoDAR are close for flat terrainPhoDAR picked up vegetation and structure not within the lidar point cloud
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AdvantagesFastAccurateCostTemporal
Flight time 5 minutesCollect GPS 15 minutesProcess data 60 minutesTotal time less than 2 hoursCollect 6 acres of surface information
FastPlanning 5 minutesCollect 6 acres of surface information in 5 minutesCollect GPS in 15 minutesProcess data collection 60 minutesTotal collection / process / product time less than 2 hoursCan LiDAR be flown this fast?How long does it take to plan LiDARHow long does it take to plan aerialThere are satellite subscription options
AccurateInitially elevation looks close to LiDAR DTMPublicly available LiDAR did not contain all points, only GroundHorizontal and Vertical corrected with high-accuracy GPS
CheapDrone is ~500Software cost free for trial. Price is unknown, reaching out to our client services.If public data is not availableHow much does LiDAR cost?
TemporalOn Demand Remote Sensing with a DroneLimitations are due to weather and light conditions
Public DataConsider time of collection for publicly available, or for company contracted?Do these data match conditions of event?
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AdvantagesFastAccurateCostTemporal
Elevation comparison shows accuracy close to LiDARPublicly available LiDAR only contained ground returnsHorizontal & Vertical accuracy dependent best available GCP
FastPlanning 5 minutesCollect 6 acres of surface information in 5 minutesCollect GPS in 15 minutesProcess data collection 60 minutesTotal collection / process / product time less than 2 hoursCan LiDAR be flown this fast?How long does it take to plan LiDARHow long does it take to plan aerialThere are satellite subscription options
AccurateInitially elevation looks close to LiDAR DTMPublicly available LiDAR did not contain all points, only GroundHorizontal and Vertical corrected with high-accuracy GPS
CheapDrone is ~500Software cost free for trial. Drone2Map ~3500yrIf public data is not availableHow much does LiDAR cost?
TemporalOn Demand Remote Sensing with a DroneLimitations are due to weather and light conditions
Public DataConsider time of collection for publicly available, or for company contracted?Do these data match conditions of event?
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AdvantagesFastAccurateCostTemporal
Drone is ~500Software cost for Drone2Map ~3500yrsUAS pilot license 150
FastPlanning 5 minutesCollect 6 acres of surface information in 5 minutesCollect GPS in 15 minutesProcess data collection 60 minutesTotal collection / process / product time less than 2 hoursCan LiDAR be flown this fast?How long does it take to plan LiDARHow long does it take to plan aerialThere are satellite subscription options
AccurateInitially elevation looks close to LiDAR DTMPublicly available LiDAR did not contain all points, only GroundHorizontal and Vertical corrected with high-accuracy GPS
CheapDrone is ~500Software cost free for trial. Drone2Map ~3500yrPilot license 150If public data is not availableHow much does LiDAR cost?
TemporalOn Demand Remote Sensing with a DroneLimitations are due to weather and light conditions
Public DataConsider time of collection for publicly available, or for company contracted?Do these data match conditions of event?
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AdvantagesFastAccurateCostTemporal
Near real time Remote SensingSeasonal, Daily, Acute Events
FastPlanning 5 minutesCollect 6 acres of surface information in 5 minutesCollect GPS in 15 minutesProcess data collection 60 minutesTotal collection / process / product time less than 2 hoursCan LiDAR be flown this fast?How long does it take to plan LiDARHow long does it take to plan aerialThere are satellite subscription options
AccurateInitially elevation looks close to LiDAR DTMPublicly available LiDAR did not contain all points, only GroundHorizontal and Vertical corrected with high-accuracy GPS
CheapDrone is ~500Software cost free for trial. Drone2Map ~3500yrPilot license 150If public data is not availableHow much does LiDAR cost?
TemporalOn Demand Remote Sensing with a DroneLimitations are due to weather and light conditions
Public DataConsider time of collection for publicly available, or for company contracted?Do these data match conditions of event?
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ApplicationsConstruction, Environmental, Emergency
Near Real-Time Photos, Videos, and Surface modelingContinuous monitoring only limited by processing rate and battery powerDocument construction site conditions & events of importancePair with existing survey operationPre-During-Post construction planning and remediationWetland DelineationVolumetricsSpans
ConstructionDocument construction conditionsUse surface information to document asbuilt conditionsPair with survey to gain synergyNear Real-Time
EnvironmentalPre and Post construction for planning and remediationNear Real-Time
EmergencyNear Real-Time Photos, Videos, and Surface modelingContinuous monitoring only limited by processing rate and battery power34
Follow UpRobust ComparisonsCollection MethodologyProcessing MethodologyPublic DatasetsHorizontal & Vertical Accuracy
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Thank You