Sandau Digital Airborne Camera

Introduction and Technology
1. Auflage 2009
ISBN: 978-1-4020-8878-0
Verlag: Springer Netherlands
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 343 Seiten

Digital airborne cameras are now penetrating the fields of photogrammetry and remote sensing. Due to the last decade's results in research and development in the fields of for instance detector technology, computing power, memory capacity position and orientation measurement it is now possible to generate with this new generation of airborne cameras different sets of geometric and spectral data with high geometric and radiometric resolutions within a single flight. This is a decisive advantage as compared to film based airborne cameras. The linear characteristic of the opto-electronic converters is the basis for the transition from an imaging camera to an images generating measuring instrument. Because of the direct digital processing chain from the airborne camera to the data products there is no need for the processes of chemical film development and digitising the film information. Failure sources as well as investments and staff costs are avoided. But the effective use of this new technology requires the knowledge of the features of the image and information generation, its possibilities and its restrictions. This book describes all components of a digital airborne camera from the object to be imaged to the mass memory device. So the image quality influencing processes in nature are described, as for instance the reflection of the electromagnetic sun spectrum at the objects to be imaged and the influence of the atmosphere. Also, the essential features of the new digital sensor system, their characteristics and parameters, are addressed and put into the system context. The complexity of the cooperation of all camera components, as for instance optics, filters, detector elements, analogue and digital electronics, software and so forth, becomes transparent. The book includes also the description of example systems.

1Dr. Rainer Sandau, PhD 1997 and habilitation 1990, is Chief Scientist at the German Aerospace Center (DLR) in Berlin, Germany. He has over 25 years of experience in airborne and spaceborne remote sensing activities. He was involved in optoelectronic ins

Autoren/Hrsg.

Sandau, Rainer

Inhaltsverzeichnis

1;Preface;4
2;Contents;6
3;Contributors;10
3.1;Editor;10
3.2;List of Authors;10
4;1 Introduction;12
4.1;1.1 From Analogue to Digital Airborne Cameras;12
4.2;1.2 Applications for Digital Airborne Cameras in Photogrammetry and Remote Sensing;19
4.3;1.3 Aircraft Camera or Satellite Camera;24
4.3.1;1.3.1 Detection, Recognition, Identification;27
4.4;1.4 Matrix Concept or Line Concept;31
4.5;1.5 Selection of Commercial Digital Airborne Cameras;38
4.5.1;1.5.1 ADS80;38
4.5.2;1.5.2 DMC;40
4.5.3;1.5.3 UltraCam;40
5;2 Foundations and Definitions;42
5.1;2.1 Introduction;42
5.2;2.2 Basic Properties of Light;45
5.3;2.3 Fourier Transforms;52
5.4;2.4 Linear Systems;67
5.5;2.5 Sampling;80
5.6;2.6 Radiometric Resolution and Noise;89
5.7;2.7 Colour;100
5.8;2.8 Time Resolution and Related Properties;106
5.9;2.9 Comparison of Film and CCD;110
5.9.1;2.9.1 Comparison of the Imaging Process and the Characteristic Curve;110
5.9.2;2.9.2 Sensitivity;112
5.9.3;2.9.3 Noise;113
5.9.4;2.9.4 Signal to Noise Ratio (SNR);113
5.9.5;2.9.5 Dynamic Range;114
5.9.6;2.9.6 MTF;115
5.9.7;2.9.7 MTF . Snr;115
5.9.8;2.9.8 Stability of Calibration;116
5.9.9;2.9.9 Spectral Range;117
5.9.10;2.9.10 Summary;118
5.10;2.10 Sensor Orientation;118
5.10.1;2.10.1 Georeferencing of Sensor Data;118
5.10.1.1;2.10.1.1 Relationship Between Sensor and Object Space;119
5.10.1.2;2.10.1.2 Self-calibration with Additional Parameters;121
5.10.1.3;2.10.1.3 Indirect Georeferencing;123
5.10.1.4;2.10.1.4 Orientation of Line-Scanner Images;125
5.10.1.5;2.10.1.5 Direct Georeferencing;126
5.10.2;2.10.2 Brief Review of GVP Concepts GPS GPS ;127
5.10.3;2.10.3 Basics of Inertial Navigation;132
5.10.4;2.10.4 Concepts of Inertial/GPS Integration;139
6;3 The Imaged Object and the Atmosphere;141
6.1;3.1 Radiation in Front of the Sensor;141
6.2;3.2 Radiation at the Sensor;144
6.3;3.3 Contrast of a Scene at the Sensor;147
6.4;3.4 Bi-directional Reflectance Distribution Function BRDF BRDF ;148
7;4 Structure of a Digital Airborne Camera;152
7.1;4.1 Introduction;152
7.1.1;4.1.1 Example;158
7.2;4.2 Optics and Mechanics;160
7.2.1;4.2.1 Effect of Geometry;160
7.2.2;4.2.2 The Effect of the Wave Nature of Light;162
7.2.3;4.2.3 Space-Bandwidth Product;162
7.2.4;4.2.4 Principal Rays;163
7.2.5;4.2.5 Physical Imaging Model;163
7.2.6;4.2.6 Data Transfer Rate of High Performance Optical System;164
7.2.7;4.2.7 Camera Constant and ''Pinhole'' Model;165
7.2.8;4.2.8 Pupil Characteristics;166
7.2.8.1;4.2.8.1 Perspective;166
7.2.8.2;4.2.8.2 Spectral Imaging;166
7.2.8.3;4.2.8.3 Radiometric Image Homogeneity;167
7.2.9;4.2.9 Design and Manufacturing Aspects;168
7.2.10;4.2.10 Summary of the Geometric Properties of an Image;169
7.2.10.1;4.2.10.1 Focal Length Focal length and Depth of Focus;169
7.2.10.2;4.2.10.2 Transmitting Power and f -Number;172
7.2.10.3;4.2.10.3 Angles on the Lens and Image Sides;172
7.2.10.4;4.2.10.4 Example;174
7.2.10.5;4.2.10.5 Swath Width and Base Length;176
7.2.10.6;4.2.10.6 Ground Pixel Size and GSD GSD ;177
7.2.11;4.2.11 Aberrations and Precision of Registration;178
7.2.12;4.2.12 Radiometric Characteristics;180
7.2.12.1;4.2.12.1 Spectral Transmittance;180
7.2.13;4.2.13 Ideal Optical Transfer Function;181
7.2.14;4.2.14 Real Optical Transfer Function;184
7.2.15;4.2.15 Field Dependency of the Optical Transfer Function;186
7.2.15.1;4.2.15.1 Area Weighting;186
7.2.15.2;4.2.15.2 Equal Weighting;187
7.2.15.3;4.2.15.3 Conclusions;188
7.3;4.3 Filter;189
7.3.1;4.3.1 Absorption Filters;189
7.3.2;4.3.2 Interference Filters;192
7.4;4.4 Opto-Electronic Converters;192
7.4.1;4.4.1 Operating Principle;193
7.4.2;4.4.2 CCD Architectures;197
7.4.2.1;4.4.2.1 Lines;198
7.4.2.2;4.4.2.2 Matrices;199
7.4.3;4.4.3 Properties and Parameters;205
7.4.3.1;4.4.3.1 Signal-to-Noise Ratio;205
7.4.3.2;4.4.3.2 Noise Sources;205
7.4.3.3;4.4.3.3 Dark Signal (or Dark Current);208
7.4.3.4;4.4.3.4 Dark-Signal Non-Uniformity ( DSNU DSNU );209
7.4.3.5;4.4.3.5 Photo Response Non-Uniformity ( PRNU PRNU );210
7.4.3.6;4.4.3.6 Dynamic Range (DR);210
7.4.3.7;4.4.3.7 Noise Measurement (Photon Transfer Curve, PTC);211
7.4.3.8;4.4.3.8 Blooming and Antiblooming; Smear and Transfer Efficiency;211
7.4.3.9;4.4.3.9 Smear;213
7.4.3.10;4.4.3.10 Quantum Efficiency, Sensitivity, Responsivity;213
7.4.3.11;4.4.3.11 Shutter;216
7.4.3.12;4.4.3.12 Modulation Transfer Function (MTF);216
7.5;4.5 Focal Plane Module;219
7.5.1;4.5.1 Basic Structure of a Focal Plane Module;219
7.6;4.6 Up-Front Electronic Components;221
7.6.1;4.6.1 CCD Control;222
7.6.2;4.6.2 Signal Pre-Processing;224
7.6.3;4.6.3 Analogue-Digital Conversion;226
7.7;4.7 Digital Computer;230
7.7.1;4.7.1 The Control Computer;230
7.7.1.1;4.7.1.1 Control and Monitoring PC and Software;231
7.7.1.2;4.7.1.2 The Image Data Channel;232
7.7.1.3;4.7.1.3 GPS/IMU System IMU;234
7.7.1.4;4.7.1.4 Power and Ambient Monitoring;235
7.7.1.5;4.7.1.5 Cabling and Integration;236
7.7.2;4.7.2 Data Compression;236
7.7.2.1;4.7.2.1 Lossless Data Compression;237
7.7.2.2;4.7.2.2 Lossy Data Compression;237
7.7.2.3;4.7.2.3 Data Normalisation;239
7.7.2.4;4.7.2.4 Compression in Hardware;240
7.7.3;4.7.3 Data Memory/Data Storage;240
7.8;4.8 Flight Management System;241
7.8.1;4.8.1 Flight Planning;242
7.8.2;4.8.2 Flight Evaluation;243
7.8.3;4.8.3 Flight Execution;243
7.8.4;4.8.4 Operator and Pilot Interface;245
7.8.5;4.8.5 Operator Concept;246
7.9;4.9 System for Measurement of Position and Attitude;247
7.9.1;4.9.1 GPS/IMU System in Operational Use;247
7.9.2;4.9.2 Integration of GPS/IMU Systems with Imaging Sensors;254
7.9.2.1;4.9.2.1 Overall System Calibration;254
7.9.2.2;4.9.2.2 Geodetic Aspects;256
7.9.2.3;4.9.2.3 Transformation of Rotation Angles;257
7.10;4.10 Camera Mount;259
7.10.1;4.10.1 Rigid Mount;259
7.10.2;4.10.2 Frequency Frequency Spectrum in Aircraft and MTF;259
7.10.2.1;4.10.2.1 Example;262
7.10.3;4.10.3 Uncontrolled Camera Mount;266
7.10.4;4.10.4 Controlled Camera Mount;267
8;5 Calibration;269
8.1;5.1 Geometric Calibration;269
8.2;5.2 Determination of Image Quality;275
8.3;5.3 Radiometric Calibration;276
9;6 Data Processing and Archiving;281
10;7 Examples of Large-Scale Digital Airborne Cameras;286
10.1;7.1 The ADS40 System: A Multiple-Line Sensor for Photogrammetry and Remote Sensing;286
10.1.1;7.1.1 Introduction;286
10.1.1.1;7.1.1.1 2nd Generation ADS40;287
10.1.1.2;7.1.1.2 3rd Generation ADS80;287
10.1.1.3;7.1.1.3 Advantages Which Speak for the Line Sensor Technology;288
10.1.1.4;7.1.1.4 Economic Aspects and Competitive Systems;288
10.1.1.5;7.1.1.5 The Path to the Ideal Lens System for Airborne Digital Cameras;289
10.1.1.6;7.1.1.6 The Definition of the Filters;290
10.1.1.7;7.1.1.7 The Choices for the Focal Plate Module;291
10.1.2;7.1.2 The Digital Control Unit;293
10.1.2.1;7.1.2.1 Control Unit CU80 and Mass Memory MM80 for the 3rd generation ADS80;296
10.1.3;7.1.3 Sensor Management;297
10.1.4;7.1.4 The Flight Planning and Navigation Navigation Software ;299
10.1.5;7.1.5 The Position and Attitude Measurement System;300
10.1.6;7.1.6 The Gyro Stabilized Mount for the ADS40;301
10.1.7;7.1.7 The Radiometric und Geometric Calibration Calibration ;302
10.1.8;7.1.8 Data Processing;304
10.1.9;7.1.9 Images Acquired with the ADS40;306
10.2;7.2 Intergraph DMC Digital Mapping Camera;314
10.2.1;7.2.1 Introduction;314
10.2.2;7.2.2 Lens Cone -- Basic Design of the DMC;315
10.2.3;7.2.3 Innovative Shutter Technology;316
10.2.4;7.2.4 CCD Sensor and Forward Motion Compensation Forward Motion Compensation;316
10.2.5;7.2.5 DMC Radiometric Resolution;318
10.2.6;7.2.6 DMC Airborne System Configuration;318
10.2.7;7.2.7 System Calibration and Photogrammetric Accuracy;319
10.3;7.3 UltraCam, Digital Large Format Aerial Frame Camera System;320
10.3.1;7.3.1 Introduction;320
10.3.2;7.3.2 UltraCamX Produces the Largest Format Digital Frame Images;321
10.3.2.1;7.3.2.1 Overview of the UltraCamX;321
10.3.2.2;7.3.2.2 The UltraCamX Sensor Unit;321
10.3.2.3;7.3.2.3 The UltraCam X Storage System;323
10.3.2.4;7.3.2.4 The UltraCam Software Components;324
10.3.3;7.3.3 UltraCam Design Concept;324
10.3.3.1;7.3.3.1 The Large-Format Panchromatic Sensor;325
10.3.3.2;7.3.3.2 The Four Band Multispectral Sensor;326
10.3.4;7.3.4 Geometric Calibration;327
10.3.4.1;7.3.4.1 The UltraCam Calibration Laboratory and Image Measurements;327
10.3.4.2;7.3.4.2 Computing the Camera Parameters;329
10.3.4.3;7.3.4.3 Post-Processing for Stitching and Additional Improvements;329
10.3.5;7.3.5 Geometric Accuracy at the 1m Level;330
10.3.5.1;7.3.5.1 Aerial Triangulation Aerial triangulation by 0 0 ;330
10.3.5.2;7.3.5.2 Aerial Triangulation by Check Points;332
10.3.5.3;7.3.5.3 Geometric Improvement by Auto-Calibration;332
10.3.6;7.3.6 Radiometric Quality and Multispectral Capability;334
10.3.7;7.3.7 The Potential of Digital Frame Cameras;335
10.3.8;7.3.8 Microsoft Photogrammetry;336
10.3.8.1;7.3.8.1 Aerial Missions;336
10.3.8.2;7.3.8.2 Best Visuals for Non-Expert Users;336
10.3.8.3;7.3.8.3 A 200 Petabyte Database?;337
11;Abbreviations;339
12;Bibliography;341
13;Index;347