Inverse Synthetic Aperture Radar Imaging With MATLAB Algorithms

Caner Özdemir, PhD, is Professor of the Department of Electrical-Electronics Engineering at Mersin University and Dean of Faculty of Engineering at Zirve University. Professor Özdemir has performed extensive research in synthetic aperture radar imaging and has developed many novel methods used in inverse synthetic aperture radar imaging.

• Preface xiiiAcknowledgments xvii1 Basics of Fourier Analysis 11.1 Forward and Inverse Fourier Transform 11.1.1 Brief History of FT 11.1.2 Forward FT Operation 21.1.3 IFT 21.2 FT Rules and Pairs 31.2.1 Linearity 31.2.2 Time Shifting 31.2.3 Frequency Shifting 41.2.4 Scaling 41.2.5 Duality 41.2.6 Time Reversal 41.2.7 Conjugation 41.2.8 Multiplication 41.2.9 Convolution 51.2.10 Modulation 51.2.11 Derivation and Integration 51.2.12 Parseval’s Relationship 51.3 Time-Frequency Representation of a Signal 51.3.1 Signal in the Time Domain 61.3.2 Signal in the Frequency Domain 61.3.3 Signal in the (JTF) Plane 71.4 Convolution and Multiplication Using FT 111.5 Filtering/Windowing 111.6 Data Sampling 141.7 DFT and FFT 141.7.1 DFT 141.7.2 FFT 161.7.3 Bandwidth and Resolutions 181.8 Aliasing 191.9 Importance of FT in Radar Imaging 191.10 Effect of Aliasing in Radar Imaging 221.11 Matlab Codes 26References 312 Radar Fundamentals 332.1 Electromagnetic (EM) Scattering 332.2 Scattering from PECs 362.3 Radar Cross Section (RCS) 372.3.1 Definition of RCS 382.3.2 RCS of Simple Shaped Objects 412.3.3 RCS of Complex Shaped Objects 422.4 Radar Range Equation 422.4.1 Bistatic Case 432.4.2 Monostatic Case 482.5 Range of Radar Detection 482.5.1 Signal-to-Noise Ratio (SNR) 502.6 Radar Waveforms 512.6.1 CW 512.6.2 FMCW 542.6.3 SFCW 572.6.4 Short Pulse 602.6.5 Chirp (LFM) Pulse 622.7 Pulsed Radar 652.7.1 PRF 652.7.2 Maximum Range and Range Ambiguity 672.7.3 Doppler Frequency 682.8 Matlab Codes 72References 773 Synthetic Aperture Radar 793.1 SAR Modes 803.2 SAR System Design 803.3 Resolutions in SAR 833.4 SAR Image Formation: Range and Azimuth Compression 853.5 Range Compression 863.5.1 Matched Filter 863.5.2 Ambiguity Function 903.6 Pulse Compression 963.6.1 Detailed Processing of Pulse Compression 973.6.2 Bandwidth, Resolution, and Compression Issues 1003.6.3 Pulse Compression Example 1013.7 Azimuth Compression 1023.7.1 Processing in Azimuth 1023.7.2 Azimuth Resolution 1063.7.3 Relation to ISAR 1073.8 SAR Imaging 1083.9 Example of SAR Imagery 1083.10 Problems in SAR Imaging 1103.10.1 Range Migration 1103.10.2 Motion Errors 1113.10.3 Speckle Noise 1123.11 Advanced Topics in SAR 1123.11.1 SAR Interferometry 1123.11.2 SAR Polarimetry 1133.12 Matlab Codes 114References 1204 Inverse Synthetic Aperture Radar Imaging and Its Basic Concepts 1214.1 SAR versus ISAR 1214.2 The Relation of Scattered Field to the Image Function in ISAR 1254.3 One-Dimensional (1D) Range Profile 1264.4 1D Cross-Range Profile 1314.5 2D ISAR Image Formation (Small Bandwidth, Small Angle) 1334.5.1 Range and Cross-Range Resolutions 1394.5.2 Range and Cross-Range Extends 1404.5.3 Imaging Multi-Bounces in ISAR 1404.5.4 Sample Design Procedure for ISAR 1444.6 2D ISAR Image Formation (Wide Bandwidth, Large Angles) 1524.6.1 Direct Integration 1544.6.2 Polar Reformatting 1584.7 3D ISAR Image Formation 1594.7.1 Range and Cross-Range Resolutions 1654.7.2 A Design Example 1654.8 Matlab Codes 169References 1855 Imaging Issues in Inverse Synthetic Aperture Radar 1875.1 Fourier-Related Issues 1875.1.1 DFT Revisited 1885.1.2 Positive and Negative Frequencies in DFT 1915.2 Image Aliasing 1945.3 Polar Reformatting Revisited 1965.3.1 Nearest Neighbor Interpolation 1965.3.2 Bilinear Interpolation 1985.4 Zero Padding 2005.5 Point Spread Function (PSF) 2025.6 Windowing 2055.6.1 Common Windowing Functions 2055.6.2 ISAR Image Smoothing via Windowing 2125.7 Matlab Codes 213References 2296 Range-Doppler Inverse Synthetic Aperture Radar Processing 2316.1 Scenarios for ISAR 2326.1.1 Imaging Aerial Targets via Ground-Based Radar 2326.1.2 Imaging Ground/Sea Targets via Aerial Radar 2346.2 ISAR Waveforms for Range-Doppler Processing 2376.2.1 Chirp Pulse Train 2386.2.2 Stepped Frequency Pulse Train 2396.3 Doppler Shift’s Relation to Cross Range 2416.3.1 Doppler Frequency Shift Resolution 2426.3.2 Resolving Doppler Shift and Cross Range 2436.4 Forming the Range-Doppler Image 2446.5 ISAR Receiver 2456.5.1 ISAR Receiver for Chirp Pulse Radar 2456.5.2 ISAR Receiver for SFCW Radar 2466.6 Quadradure Detection 2476.6.1 I-Channel Processing 2486.6.2 Q-Channel Processing 2496.7 Range Alignment 2506.8 Defining the Range-Doppler ISAR Imaging Parameters 2526.8.1 Image Frame Dimension (Image Extends) 2526.8.2 Range–Cross-Range Resolution 2536.8.3 Frequency Bandwidth and the Center Frequency 2536.8.4 Doppler Frequency Bandwidth 2546.8.5 PRF 2546.8.6 Coherent Integration (Dwell) Time 2556.8.7 Pulse Width 2566.9 Example of Chirp Pulse-Based Range-Doppler ISAR Imaging 2566.10 Example of SFCW-Based Range-Doppler ISAR Imaging 2626.11 Matlab Codes 264References 2707 Scattering Center Representation of Inverse Synthetic Aperture Radar 2717.1 Scattering/Radiation Center Model 2727.2 Extraction of Scattering Centers 2747.2.1 Image Domain Formulation 2747.2.2 Fourier Domain Formulation 2837.3 Matlab Codes 287References 2978 Motion Compensation for Inverse Synthetic Aperture Radar 2998.1 Doppler Effect Due to Target Motion 3008.2 Standard MOCOMP Procedures 3028.2.1 Translational MOCOMP 3038.2.2 Rotational MOCOMP 3048.3 Popular MOCOMP Techniques in ISAR 3068.3.1 Cross-Correlation Method 3068.3.2 Minimum Entropy Method 3118.3.3 JTF-Based MOCOMP 3168.3.4 Algorithm for JTF-Based Translational and Rotational MOCOMP 3218.4 Matlab Codes 328References 3429 Some Imaging Applications Based on Inverse Synthetic Aperture Radar 3459.1 Imaging Antenna-Platform Scattering: ASAR 3469.1.1 The ASAR Imaging Algorithm 3479.1.2 Numerical Example for ASAR Imagery 3529.2 Imaging Platform Coupling between Antennas: ACSAR 3539.2.1 The ACSAR Imaging Algorithm 3569.2.2 Numerical Example for ACSAR 3589.3 Imaging Scattering from Subsurface Objects: GPR-SAR 3599.3.1 The GPR Problem 3629.3.2 Focused GPR Images Using SAR 3649.3.3 Applying ACSAR Concept to the GPR Problem 369References 372Appendix 375Index 379