Digital Airborne Camera: Introduction and Technology

349 Pages·2010·11.02 MB·English

by  Dr. Rainer Sandau (auth.)

Digital Airborne Camera
Digital Airborne Camera
Introduction and Technology
Edited by
RainerSandau
DLR,Berlin,Germany
With contributions by Ulrich Beisl, Bernhard Braunecker, MichaelCramer,
HansDriescher,AndreasEckardt,PeterFricker,MichaelGruber,StefanHilbert,
KarstenJacobsen,WalfriedJagschitz,HerbertJahn,WernerKirchhofer,Franz
Leberl,KlausJ.Neumann,RainerSandau,MariavonSchönermark,andUdo
Tempelmann
123
Editor
Dr.RainerSandau
DeutschesZentrumfor
Luft-undRaumfahrte.V.
(DLR)
Rutherfordstr.2
12489Berlin
Germany
[e-mail]
ThisisatranslationofthebookinGerman“DigitaleLuftbildkamera−EinführungundGrundlagen”,
byRainerSandau,publishedbyWichmannVerlag,2005;includingsomenewadditionsinchapter7
(Examples)
ISBN978-1-4020-8877-3 e-ISBN978-1-4020-8878-0
DOI10.1007/978-1-4020-8878-0
SpringerDordrechtHeidelbergLondonNewYork
LibraryofCongressControlNumber:2009940584
©SpringerScience+BusinessMediaB.V.2010
Nopartofthisworkmaybereproduced,storedinaretrievalsystem,ortransmittedinanyformorby
anymeans,electronic,mechanical,photocopying,microfilming,recordingorotherwise,withoutwritten
permissionfromthePublisher,withtheexceptionofanymaterialsuppliedspecificallyforthepurpose
ofbeingenteredandexecutedonacomputersystem,forexclusiveusebythepurchaserofthework.
Coverillustration:TransparentviewoftheADS40cameramadebyLeicaGeosystemsAG.
Printedonacid-freepaper
SpringerispartofSpringerScience+BusinessMedia(www.springer.com)
Preface
Digital airborne cameras are now penetrating the market of photogrammetry and
remotesensing.Owingtorapidprogressinthelast10yearsinfieldssuchasdetec-
tor technology, computer power, memory capacity, and measurement of position
and orientation, it is now possible to acquire, with the new generation of digital
airbornecameras,differentsetsofgeometricandspectraldatawithhighresolution
within a single flight. This is a decisive advantage over aerial film cameras. The
linear characteristic of the optoelectronic converters is at the root of this transfor-
mation from an imaging camera to a measuring instrument that captures images.
The direct digital processing chain from the airborne camera to the derived prod-
ucts involves no chemical film development or digitisation in a photogrammetric
filmscanner.Causesoffailure,expensiveinvestmentsandprohibitivestaffcostsare
avoided.Theeffectiveuseofthisnewtechnology,however,requiresknowledgeof
thecharacteristics,possibilitiesandrestrictionsoftheformationofimagesandthe
generationofinformationfromthem.
This book describes all the components of a digital airborne camera, from the
objecttobeimagedtothemassmemorydeviceonwhichtheimageryiswrittenin
theair.Thusnaturalprocessesinfluencingimagequalityareconsidered,suchasthe
reflection of the electromagnetic energy from the sun by the object being imaged
and the influence of the atmosphere. The essential features and related parame-
ters of the new technology are discussed and placed in a system framework. The
complex interdependencies between the components, for example, optics, filters,
detectors, analogue and digital electronics, and software, become apparent. The
bookdescribesseveralsystemsavailableonthemarketatthetimeofwriting.
The book will appeal to all who want to be informed about the technology of
thenewgenerationofdigitalairbornecameras.Groupsofpotentialreadersinclude:
managers who have to decide about investment in and use of the new cameras;
camera operators whose knowledge of the features of the cameras is essential to
the quality of the data acquired; users of derived products who want to order or
effectivelyprocessthenewdigitaldatasets;andscientistsanduniversitystudents,
inphotogrammetry,remotesensing,geodesy,cartography,geospatialandenviron-
mentalsciences,forestry,agriculture,urbanplanning,landusemonitoringandother
fields,whoneedtopreparefortheuseofthenewcamerasandtheirimagery.
v
vi Preface
This book is a translation of the publication in German, Digitale
Luftbildkamera − Einführung und Grundlagen, published in 2005 by Herbert
Wichmann Verlag in Heidelberg. Only Chapter 7 was extended to three example
camerasystemswhicharebeingmarketedworldwideandarealsoroughlyrepresen-
tativeofthebandwidthoftheimplementationvariations.Iwouldliketoacknowl-
edgeWichmannVerlag’sgraciousagreementtotransfertheEnglish-languagerights
toSpringer.
I would like also to acknowledge the help that the contributors to this book
receivedfromanumberofindividuals:
Ms.UteDombrowski(DLR,Berlin,Germany),whowasverysupportiveintyp-
inglargepartsofthemanuscript,dealingwithfiguresandtables,editingthechapters
ofthevariousauthors,andcombiningtheresultsintoabook.
Dr. A. Stewart Walker (BAE Systems, San Diego, USA), who proof-read the
entire manuscript in order to polish and homogenise the usage of the English
languageinthetranslationfromGermancarriedoutbytheauthors.
Dipl.-Ing.DieterZeuner(formerlyApplanix,Toronto,Canada),whocontributed
tothetranslationoftheGermanversion.
Prof. Dr.-Ing. Hans-Peter Röser (Unversität Stuttgart, Institut für
Photogrammetrie, Germany; formerly DLR, Berlin, Germany), who led the
DLRteamduringthejointdevelopmentoftheADS40withLeicaandLHSystems.
Ms. Petra van Steenbergen of the publisher, who supported the creation of the
bookthroughpleasant,patientcollaboration.
Berlin,Germany RainerSandau
April2009
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 FromAnaloguetoDigitalAirborneCameras . . . . . . . . . . 1
1.2 Applications for Digital Airborne Cameras
inPhotogrammetryandRemoteSensing. . . . . . . . . . . . . 8
1.3 AircraftCameraorSatelliteCamera . . . . . . . . . . . . . . . 13
1.3.1 Detection,Recognition,Identification . . . . . . . . . 16
1.4 MatrixConceptorLineConcept . . . . . . . . . . . . . . . . . 20
1.5 SelectionofCommercialDigitalAirborneCameras . . . . . . . 27
1.5.1 ADS80. . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.5.2 DMC . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1.5.3 UltraCam . . . . . . . . . . . . . . . . . . . . . . . . 29
2 FoundationsandDefinitions . . . . . . . . . . . . . . . . . . . . . . 31
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.2 BasicPropertiesofLight . . . . . . . . . . . . . . . . . . . . . 34
2.3 FourierTransforms . . . . . . . . . . . . . . . . . . . . . . . . 41
2.4 LinearSystems . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2.5 Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
2.6 RadiometricResolutionandNoise . . . . . . . . . . . . . . . . 78
2.7 Colour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
2.8 TimeResolutionandRelatedProperties . . . . . . . . . . . . . 95
2.9 ComparisonofFilmandCCD . . . . . . . . . . . . . . . . . . 99
2.9.1 ComparisonoftheImagingProcessandthe
CharacteristicCurve. . . . . . . . . . . . . . . . . . . 99
2.9.2 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . 101
2.9.3 Noise . . . . . . . . . . . . . . . . . . . . . . . . . . 102
2.9.4 SignaltoNoiseRatio(SNR) . . . . . . . . . . . . . . 102
2.9.5 DynamicRange . . . . . . . . . . . . . . . . . . . . . 103
2.9.6 MTF . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
2.9.7 MTF·Snr . . . . . . . . . . . . . . . . . . . . . . . . 104
2.9.8 StabilityofCalibration . . . . . . . . . . . . . . . . . 105
2.9.9 SpectralRange . . . . . . . . . . . . . . . . . . . . . 106
2.9.10 Summary . . . . . . . . . . . . . . . . . . . . . . . . 107
vii
viii Contents
2.10 SensorOrientation . . . . . . . . . . . . . . . . . . . . . . . . 107
2.10.1 GeoreferencingofSensorData . . . . . . . . . . . . . 107
2.10.2 BriefReviewofGVPConceptsGPS . . . . . . . . . . 116
2.10.3 BasicsofInertialNavigation . . . . . . . . . . . . . . 121
2.10.4 ConceptsofInertial/GPSIntegration . . . . . . . . . . 128
3 TheImagedObjectandtheAtmosphere . . . . . . . . . . . . . . . 131
3.1 RadiationinFrontoftheSensor . . . . . . . . . . . . . . . . . 131
3.2 RadiationattheSensor . . . . . . . . . . . . . . . . . . . . . . 134
3.3 ContrastofaSceneattheSensor. . . . . . . . . . . . . . . . . 137
3.4 Bi-directionalReflectanceDistributionFunctionBRDF. . . . . 138
4 StructureofaDigitalAirborneCamera . . . . . . . . . . . . . . . 143
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
4.1.1 Example . . . . . . . . . . . . . . . . . . . . . . . . . 149
4.2 OpticsandMechanics . . . . . . . . . . . . . . . . . . . . . . 151
4.2.1 EffectofGeometry . . . . . . . . . . . . . . . . . . . 151
4.2.2 TheEffectoftheWaveNatureofLight. . . . . . . . . 153
4.2.3 Space-BandwidthProduct. . . . . . . . . . . . . . . . 153
4.2.4 PrincipalRays . . . . . . . . . . . . . . . . . . . . . . 154
4.2.5 PhysicalImagingModel . . . . . . . . . . . . . . . . 154
4.2.6 Data Transfer Rate of High Performance
OpticalSystem . . . . . . . . . . . . . . . . . . . . . 155
4.2.7 CameraConstantand“Pinhole”Model . . . . . . . . . 156
4.2.8 PupilCharacteristics . . . . . . . . . . . . . . . . . . 157
4.2.9 DesignandManufacturingAspects . . . . . . . . . . . 159
4.2.10 SummaryoftheGeometricPropertiesofanImage. . . 160
4.2.11 AberrationsandPrecisionofRegistration . . . . . . . 169
4.2.12 RadiometricCharacteristics . . . . . . . . . . . . . . . 171
4.2.13 IdealOpticalTransferFunction . . . . . . . . . . . . . 172
4.2.14 RealOpticalTransferFunction . . . . . . . . . . . . . 175
4.2.15 FieldDependencyoftheOpticalTransferFunction . . 177
4.3 Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
4.3.1 AbsorptionFilters . . . . . . . . . . . . . . . . . . . . 180
4.3.2 InterferenceFilters . . . . . . . . . . . . . . . . . . . 183
4.4 Opto-ElectronicConverters . . . . . . . . . . . . . . . . . . . 183
4.4.1 OperatingPrinciple . . . . . . . . . . . . . . . . . . . 184
4.4.2 CCDArchitectures . . . . . . . . . . . . . . . . . . . 188
4.4.3 PropertiesandParameters . . . . . . . . . . . . . . . . 196
4.5 FocalPlaneModule . . . . . . . . . . . . . . . . . . . . . . . 210
4.5.1 BasicStructureofaFocalPlaneModule . . . . . . . . 210
4.6 Up-FrontElectronicComponents . . . . . . . . . . . . . . . . 212
4.6.1 CCDControl . . . . . . . . . . . . . . . . . . . . . . 213
4.6.2 SignalPre-Processing . . . . . . . . . . . . . . . . . . 215
4.6.3 Analogue-DigitalConversion . . . . . . . . . . . . . . 217
4.7 DigitalComputer . . . . . . . . . . . . . . . . . . . . . . . . . 221
Contents ix
4.7.1 TheControlComputer . . . . . . . . . . . . . . . . . 221
4.7.2 DataCompression . . . . . . . . . . . . . . . . . . . . 227
4.7.3 DataMemory/DataStorage . . . . . . . . . . . . . . . 231
4.8 FlightManagementSystem . . . . . . . . . . . . . . . . . . . 232
4.8.1 FlightPlanning . . . . . . . . . . . . . . . . . . . . . 233
4.8.2 FlightEvaluation . . . . . . . . . . . . . . . . . . . . 234
4.8.3 FlightExecution . . . . . . . . . . . . . . . . . . . . . 234
4.8.4 OperatorandPilotInterface . . . . . . . . . . . . . . . 236
4.8.5 OperatorConcept . . . . . . . . . . . . . . . . . . . . 237
4.9 SystemforMeasurementofPositionandAttitude . . . . . . . . 238
4.9.1 GPS/IMUSysteminOperationalUse . . . . . . . . . 238
4.9.2 IntegrationofGPS/IMUSystemswithImagingSensors 245
4.10 CameraMount . . . . . . . . . . . . . . . . . . . . . . . . . . 250
4.10.1 RigidMount . . . . . . . . . . . . . . . . . . . . . . . 250
4.10.2 FrequencySpectruminAircraftandMTF . . . . . . . 250
4.10.3 UncontrolledCameraMount . . . . . . . . . . . . . . 257
4.10.4 ControlledCameraMount . . . . . . . . . . . . . . . 258
5 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
5.1 GeometricCalibration . . . . . . . . . . . . . . . . . . . . . . 261
5.2 DeterminationofImageQuality . . . . . . . . . . . . . . . . . 267
5.3 RadiometricCalibration . . . . . . . . . . . . . . . . . . . . . 268
6 DataProcessingandArchiving . . . . . . . . . . . . . . . . . . . . 273
7 ExamplesofLarge-ScaleDigitalAirborneCameras. . . . . . . . . 279
7.1 The ADS40 System: A Multiple-Line Sensor
forPhotogrammetryandRemoteSensing . . . . . . . . . . . . 279
7.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . 279
7.1.2 TheDigitalControlUnit . . . . . . . . . . . . . . . . 286
7.1.3 SensorManagement . . . . . . . . . . . . . . . . . . . 290
7.1.4 TheFlightPlanningandNavigationSoftware . . . . . 292
7.1.5 ThePositionand AttitudeMeasurementSystem . . . . 293
7.1.6 TheGyroStabilizedMountfortheADS40 . . . . . . . 294
7.1.7 TheRadiometricundGeometricCalibration . . . . . . 295
7.1.8 DataProcessing . . . . . . . . . . . . . . . . . . . . . 297
7.1.9 ImagesAcquiredwiththeADS40 . . . . . . . . . . . 299
7.2 IntergraphDMCDigitalMappingCamera . . . . . . . . . . . . 307
7.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . 307
7.2.2 LensCone–BasicDesignoftheDMC . . . . . . . . . 308
7.2.3 InnovativeShutterTechnology . . . . . . . . . . . . . 309
7.2.4 CCD Sensor and Forward Motion
Compensation . . . . . . . . . . . . . . . . . . . . . 309
7.2.5 DMCRadiometricResolution . . . . . . . . . . . . . 311
7.2.6 DMCAirborneSystemConfiguration . . . . . . . . . 311
7.2.7 SystemCalibrationandPhotogrammetricAccuracy . . 312
x Contents
7.3 UltraCam,DigitalLargeFormatAerialFrameCameraSystem . 313
7.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . 313
7.3.2 UltraCamX Produces the Largest Format
DigitalFrameImages . . . . . . . . . . . . . . . . . . 314
7.3.3 UltraCamDesignConcept . . . . . . . . . . . . . . . 317
7.3.4 GeometricCalibration. . . . . . . . . . . . . . . . . . 320
7.3.5 GeometricAccuracyatthe1μmLevel . . . . . . . . . 323
7.3.6 RadiometricQualityandMultispectralCapability . . . 327
7.3.7 ThePotentialofDigitalFrameCameras . . . . . . . . 328
7.3.8 MicrosoftPhotogrammetry . . . . . . . . . . . . . . . 329
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
Contributors
Editor
Dr.RainerSandau
ListofAuthors
Dr.UlrichBeisl Section
LeicaGeosystemsAG,Heerbrugg,Switzerland 2.9
Dr.BernhardBraunecker
LeicaGeosystemsAG,Heerbrugg,Switzerland 4.2,4.3
Dr.MichaelCramer
UniversitätStuttgart,InstitutfürPhotogrammetrie,Stuttgart,Germany 2.10,4.9
Dr.HansDriescher
DeutschesZentrumfürLuft-undRaumfahrt(DLR),Berlin,Germany 4.5
Dr.AndreasEckardt
DeutschesZentrumfürLuft-undRaumfahrt(DLR),Berlin,Germany 2.8
Dipl.-Ing.PeterFricker
LeicaGeosystemsAG,Heerbrugg,Switzerland 7.1
Dr.MichaelGruber
MicrosoftPhotogrammetry,Graz,Austria 7.3
Dipl.-Ing.StefanHilbert
DeutschesZentrumfürLuft-undRaumfahrt(DLR),Berlin,Germany 4.4,4.6
Dr.KarstenJacobsen
LeibnizUniversitätHannover,InstitutfürPhotogrammetrieund
GeoInformation,Hannover,Germany 2.10
Dipl.-Ing.WalfriedJagschitz
LeicaGeosystemsAG,Heerbrugg,Switzerland 4.10
xi