 | Villano M. Staggered synthetic aperture radar: Diss. … Dr.-Ing. / Deutsches Zentrum für Luft- und Raumfahrt, Institut für Hochfrequenztechnik und Radarsysteme, Oberpfaffenhofen. - Köln: DLR, 2016. - xvi, 161 p.: ill., tab. - (Forschungsbericht; 2016-16). - Res. also Germ. - Bibliogr.: p. 147-155. - ISSN 1434-8454
Шифр: (Pr 1120/2016-16) 02
|
Zusammenfassung ................................................. v
Abstract ...................................................... vii
Acronyms and Symbols ........................................... ix
1 Introduction ............................................... 1
1.1 State of the Art: Spaceborne SAR Sensors ................... 2
1.2 Motivation, Objectives, and Structure of the Thesis ........ 5
2 SAR Remote Sensing ......................................... 9
2.1 Geometry and Acquisition Process ........................... 9
2.2 Signal Processing ......................................... 11
2.2.1 The Range Dimension ................................ 11
2.2.2 The Azimuth Dimension .............................. 14
2.3 System Performance ........................................ 17
2.3.1 Resolution and Sidelobes ........................... 17
2.3.2 Distributed Scatterers and Speckle ................. 17
2.3.3 Noise Equivalent Sigma Zero ........................ 18
2.3.4 Azimuth Ambiguities ................................ 18
2.3.5 Range Ambiguities and Nadir Returns ................ 20
3 High-Resolution Wide-Swath Imaging ........................ 23
3.1 Azimuth Resolution and Swath Width ........................ 23
3.2 Digital Beamforming and Multiple Receive Subapertures ..... 26
3.2.1 Multi-Channel Processing ........................... 28
3.3 New Architectures and Concepts ............................ 30
3.3.1 Multi-Channel ScanSAR .............................. 30
3.3.2 Multiple Elevation Beams ........................... 30
4 Staggered SAR ............................................. 33
4.1 Concept ................................................... 33
4.1.1 Processing Strategies .............................. 34
4.2 Design of Sequences of PRIs ............................... 35
4.2.1 Slow PRI Change .................................... 36
4.2.2 Fast PRI Change .................................... 38
4.2.3 More Elaborated Sequences .......................... 46
4.2.4 Sequences for Fully Polarimetrie SAR Systems ....... 47
4.3 Interpolation Methods ..................................... 49
4.3.1 Two-Point Linear Interpolation ..................... 50
4.3.2 Multi-Channel Reconstruction ....................... 50
4.3.3 Best Linear Unbiased (BLU) Interpolation ........... 53
5 Performance Analysis and Design Examples .................. 55
5.1 Input Parameters and Performance Measurements ............. 55
5.2 Impact on Performance of the Features Peculiar of
a Staggered SAR System .................................... 64
5.2.1 Impact of the Sequence of PRIs on Performance ...... 64
5.2.2 Impact of the Interpolation Method on Performance .. 70
5.2.3 Impact of the Processing Strategy on Performance ... 71
5.3 System Design Considerations .............................. 73
5.3.1 Mean PRF on Transmit ............................... 73
5.3.2 Processed Doppler Bandwidth ........................ 76
5.3.3 Duty Cycle ......................................... 77
5.3.4 Fully Polarimetrie SAR Systems ..................... 78
5.4 C-Band Design Examples Based on a Planar Antenna .......... 80
6 Experiments with Real Data ................................ 87
6.1 F-SAR Experiment .......................................... 87
6.1.1 Generation of Equivalent Staggered SAR Data ........ 87
6.1.2 Performance Assessment on Raw Data ................. 92
6.1.3 Data Focusing and Impulse Response Analysis ........ 94
6.2 TerraSAR-X Experiment .................................... 106
6.2.1 Characteristics of TerraSAR-X and Experiment
Definition ........................................ 106
6.2.2 TerraSAR-X Data Processing and Analysis of the
Results ........................................... 114
7 Data Volume Reduction .................................... 119
7.1 HRWS Systems and Azimuth Oversampling .................... 119
7.2 On-Board Doppler Filtering and Decimation ................ 120
7.3 FIR Filter Design ........................................ 122
7.4 Performance Analysis ..................................... 125
7.5 Joint Effects of Doppler Filtering and Quantization ...... 129
8 Staggered SAR with Displaced Phase Centers ............... 133
8.1 Concept .................................................. 133
8.2 System Design ............................................ 134
9 Conclusions .............................................. 141
9.1 Discussion ............................................... 141
9.2 Summary of Results ....................................... 143
9.3 Outlook .................................................. 145
Bibliography .................................................. 147
A Spherical SAR Geometry ...................................... 157
Curriculum Vitae .............................................. 161
|
|
