Leigsnering Sparsity-Based Multipath Exploitation for Through-the-Wall Radar Imaging

1. Auflage 2018
ISBN: 978-3-319-74283-0
Verlag: Springer Nature Switzerland
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 124 Seiten

Reihe: Springer Theses

This thesis reports on sparsity-based multipath exploitation methods for through-the-wall radar imaging. Multipath creates ambiguities in the measurements provoking unwanted ghost targets in the image. This book describes sparse reconstruction methods that are not only suppressing the ghost targets, but using multipath to one's advantage. With adopting the compressive sensing principle, fewer measurements are required for image reconstruction as compared to conventional techniques. The book describes the development of a comprehensive signal model and some associated reconstruction methods that can deal with many relevant scenarios, such as clutter from building structures, secondary reflections from interior walls, as well as stationary and moving targets, in urban radar imaging. The described methods are evaluated here using simulated as well as measured data from semi-controlled laboratory experiments.

Autoren/Hrsg.

Leigsnering, Michael

Inhaltsverzeichnis

1;Supervisor’s Foreword;6
2;Supervisor’s Foreword;8
3;Acknowledgements;10
4;Contents;12
5;Acronyms;15
6;Symbols;17
7;1 Introduction and Motivation;21
7.1;1.1 Motivation;22
7.2;1.2 State-of-the-Art;22
7.3;1.3 Contributions;24
7.4;1.4 Thesis Overview;24
7.5;References;25
8;2 Fundamentals of Compressive Sensing;29
8.1;2.1 Assumptions and Conditions for Reconstruction;30
8.1.1;2.1.1 Sensing on Linear Bases;30
8.1.2;2.1.2 Sparsity;31
8.1.3;2.1.3 Conditions on the Measurement Matrix;32
8.2;2.2 Reconstruction Algorithms;33
8.2.1;2.2.1 Optimization-Based Approaches;34
8.2.2;2.2.2 Greedy Approaches;35
8.3;2.3 Application to Through-the-Wall Radar Imaging;36
8.4;References;37
9;3 Signal Model;40
9.1;3.1 Ultra-Wideband Signal Model;41
9.2;3.2 Stepped-Frequency Signal Model;43
9.3;3.3 Multipath Propagation;44
9.3.1;3.3.1 Direct Path and Wall Ringing Multipath;46
9.3.2;3.3.2 Interior Wall Multipath;47
9.3.3;3.3.3 Bistatic Received Signal Model;48
9.4;3.4 Direct Wall Reflections;51
9.5;3.5 Efficient Sampling Schemes;53
9.5.1;3.5.1 Ultra-Wideband Pulse Radar;54
9.5.2;3.5.2 Stepped-Frequency Radar;54
9.6;References;55
10;4 Sparsity-Based Multipath Exploitation;57
10.1;4.1 Motivation;57
10.2;4.2 Conventional Image Formation;58
10.3;4.3 Stationary Targets;60
10.3.1;4.3.1 Conventional Sparse Reconstruction;61
10.3.2;4.3.2 Group Sparse Reconstruction;61
10.3.3;4.3.3 Sparse Reconstruction with Overlapping Groups;63
10.3.4;4.3.4 Simulation and Experimental Results;65
10.4;4.4 Stationary and Moving Targets;68
10.4.1;4.4.1 Apparent Doppler Speed;68
10.4.2;4.4.2 Joint Target Location and Velocity Estimation;70
10.4.3;4.4.3 Target Location Reconstruction with Subsequent Velocity Estimation;71
10.4.4;4.4.4 Simulation and Experimental Results;74
10.5;4.5 Distributed Radar;82
10.5.1;4.5.1 Multiple Radar Unit Model;82
10.5.2;4.5.2 Dictionary Analysis;84
10.5.3;4.5.3 Joint Group Sparse Reconstruction;86
10.5.4;4.5.4 Simulation Results;88
10.6;4.6 Conclusions;92
10.7;References;92
11;5 Mitigating Wall Effects and Uncertainties;95
11.1;5.1 Motivation;95
11.2;5.2 Front Wall Reflections;97
11.2.1;5.2.1 Wall Reflection Model;97
11.2.2;5.2.2 Separate Reconstruction;99
11.2.3;5.2.3 Joint Group Sparse Reconstruction;99
11.2.4;5.2.4 Joint Overlapping Group Sparse Reconstruction;100
11.2.5;5.2.5 Simulation and Experimental Results;101
11.3;5.3 Wall Location Correction;105
11.3.1;5.3.1 Multipath Model Including Wall Position Errors;105
11.3.2;5.3.2 Joint Sparse Reconstruction and Wall Position Estimation;106
11.3.3;5.3.3 Simulation and Experimental Results;108
11.4;5.4 Conclusions;114
11.5;References;114
12;6 Conclusions and Outlook;116
12.1;6.1 Conclusions;116
12.1.1;6.1.1 Multipath Model;116
12.1.2;6.1.2 Sparsity-Based Multipath Exploitation;117
12.1.3;6.1.3 Mitigating Wall Effects and Uncertainties;117
12.2;6.2 Outlook;118
12.2.1;6.2.1 Signal Model;118
12.2.2;6.2.2 Sparsity-Based Multipath Exploitation;118
12.2.3;6.2.3 Sparse Reconstruction with Parameter Uncertainties;119
12.3;References;119
13;A;121
13.1;A.1 Complex Amplitude Derivation;121
13.2;A.2 Justification of the Invariance of Complex Amplitude Across the Array;122
14;Appendix Curriculum Vitae;123