Spotlight-Mode Synthetic Aperture Radar: A Signal Processing Approach

1 Range Resolving Techniques.- 1.1 Introduction to Imaging Radars.- 1.2 Range Resolution in Imaging Radars Using CW Pulses.- 1.3 Range Resolution Using Dispersed Waveforms.- References.- 2 A Tomographic Foundation for Spotlight-Mode Sar Imaging.- 2.1 The Cross-Range Resolution Problem.- 2.2 The Concept of Aperture Synthesis as a Solution to the Cross-Range Resolvability Problem.- 2.3 Mathematics of Computerized Axial Tomography (CAT).- 2.4 A Three-Dimensional Tomographic Framework for Spotlight-Mode SAR.- 2.5 The Complex Reconstructed Spotlight-Mode SAR Image.- 2.6 Limitations of the Tomographic Paradigm.- 2.7 Tomographic Development of Bistatic SAR.- References.- 3 Aspects of Spotlight-Mode Image Formation.- 3.1 Introduction.- 3.2 Image Resolution and Area Coverage.- 3.3 Holographic Properties and Multi-look Concepts.- 3.4 Properties of Non-polar-formatted Data.- 3.5 Polar-to-Rectangular Resampling.- 3.6 Fourier Transforms, Aperture Weighting, and Oversampling.- 3.7 Slant-Plane Image Formation and Image Properties.- 3.8 Out-of-Plane Correction and Projection Effects.- 3.9 Ground-Plane Image Formation and Image Properties.- 3.10 Spatial Frequencies, Image Scale Factors, Image Dimensions, Oversampling, and Resolution Summarized.- 3.11 A Typical Image-Formation Procedure.- References.- 4 Phase Errors and Autofocus in Sar Imagery.- 4.1 Introduction.- 4.2 Mathematical Model for Demodulation Inaccuracies.- 4.3 Phase Errors Induced Across the Aperture.- 4.4 Phase Correction using Conventional Approaches.- 4.5 Phase Correction Using PGA.- References.- 5 Interferometric Processing of Sar Data.- 5.1 Introduction.- 5.2 Review of Theoretical Fundamentals.- 5.3 Interferometric Pair Processing: Registration.- 5.4 Interferometric Terrain Mapping.- 5.5 Interferometric Change Detection.- 5.6 Interferometric Terrain Motion Mapping.- 5.7 Stereoscopic Terrain Mapping.- References.- A Rotation Property of Fourier Transforms.- B Phase Analysis for Limitations of the Tomographic Paradigm.- B.l The Phase of the Return from a Point Target.- B.2 The Range Curvature Effect.- B.3 Deramp Residual Phase Error.- C Development of a Practical Image Formation Geometry.- C.l Introduction.- C.2 Imaging Geometry and Coordinate System Development.- C.5 Computing the Shadow Angle (?).- C.7 Computing the Fractional Range and Cross-range Layover Components in the Ground Plane.- C.8 Computing the Slant-Plane Image Shear Angle (?).- C.9 Summary.- D Development of a Synthetic Target Generator.- D.l Introduction.- D.2 Synthetic Target Generator.- E Some Simple Synthetic Target Examples.- E.l Introduction.- E.2 Examples of Synthetically Generated Phase Histories and Imagery.- F ML Phase Estimation and the Cramer-Rao Lower Bound.- F.l Derivation of the Maximum-Likelihood Phase Estimator.- F.2 Estimator Bias.- F.3 The Cramer-Rao Lower Bound.