Читать книгу Inverse Synthetic Aperture Radar Imaging With MATLAB Algorithms - Caner Ozdemir - Страница 4

1 Chapter 1Figure 1.1 The time‐domain signal of “prince” spoken by a lady.Figure 1.2 The frequency‐domain signal (or the spectrum) of “prince.”Figure 1.3 The time‐frequency representation of the word “prince.”Figure 1.4 Images of scattering mechanisms in the joint time–frequency plane...Figure 1.5 JTF image of a backscattered measured data from a dielectric‐coat...Figure 1.6 An ideal and real LP filter characteristics.Figure 1.7 Some common window characteristics.Figure 1.8 Effect of windowing. (a) Rectangular time signal, (b) its Fourier...Figure 1.9 Sampling. (a) continuous time signal, (b) discrete‐time signal af...Figure 1.10 Impulse comb waveform composed of ideal impulses.Figure 1.11 An example of DFT operation: (a) discrete time‐domain signal, (b...Figure 1.12 (a) Monostatic radar configuration, (b) scattered field versus f...Figure 1.13 Simulated range profile of an airplane.Figure 1.14 Simulated 2D ISAR image of an airplane.Figure 1.15 SAR image of the famous “hook” of Cape Cod, Massachusetts, USA....Figure 1.16 The Nyquist sampling procedure for getting unaliased range image...Figure 1.17 The effect of sampling rate. (a) No aliasing due to oversampling...

2 Chapter 2Figure 2.1 Different scattering mechanisms: (a) specular reflection, (b) sca...Figure 2.2 Electromagnetic scattering from a perfectly conducting object.Figure 2.3 The EM energy scatters in all directions when it hits a target.Figure 2.4 RCS values for perfectly conducting simple objects (all objects a...Figure 2.5 Simulated RCS (in dBsm) of an aircraft model at 2 GHz as a functi...Figure 2.6 Geometry for obtaining bistatic radar range equation.Figure 2.7 Geometry for obtaining monostatic radar range equation.Figure 2.8 Minimum receiver power corresponding to maximum range of radar.Figure 2.9 An example of CW radar waveform in (a) time domain, (b) frequency...Figure 2.10 Operation of police radar: (a) returned wave has the same freque...Figure 2.11 A linear frequency‐modulated continuous wave signal.Figure 2.12 Operation of LFMCW radar: (a) time‐frequency display of the tran...Figure 2.13 LFMCW radar block diagram.Figure 2.14 SFCW signal in time‐frequency plane.Figure 2.15 Range profile of a point target is obtained with the help of SFC...Figure 2.16 A short‐duration rectangular pulse in (a) time domain, (b) frequ...Figure 2.17 A short‐duration single‐frequency pulse in (a) time domain, (b) ...Figure 2.18 A short‐duration Mexican‐hat pulse in (a) time domain, (b) frequ...Figure 2.19 Comparison of the time‐domain pulse waveforms: (a) single‐tone p...Figure 2.20 Comparison of the spectrum of (a) single‐tone pulse and (b) LFM ...Figure 2.21 Pulsed radar systems use a sequence of modulated pulses.Figure 2.22 Illustration of Doppler shift phenomenon: (a) the leading edge o...Figure 2.23 Doppler shift is caused by the target's radial velocity, v_r.

3 Chapter 3Figure 3.1 Modes of SAR operation. (a) strip‐map SAR, (b) spotlight SAR, (c)...Figure 3.2 General block‐diagram of a SAR system.Figure 3.3 A real aperture single antenna that provides an azimuth resolutio...Figure 3.4 Basic SAR operation: Radar platform is moving to synthesize the e...Figure 3.5 SAR image is formed by applying range compression and azimuth com...Figure 3.6 The matched filter receiver.Figure 3.7 The matched filter realization via FFT processing.Figure 3.8 The matched filter example. (a) transmitted rectangular pulse, (b...Figure 3.9 Ideal ambiguity function represented by the radar ambiguity diagr...Figure 3.10 Normalized rectangular pulse ambiguity function (a) in the radar...Figure 3.11 Normalized LFM pulse ambiguity function (a) in the radar ambigui...Figure 3.12 Time‐frequency plot for an (a) upchirp signal, (b) downchirp sig...Figure 3.13 Output signal after the pulse compression process.Figure 3.14 The matched filter example: (a) transmitted chirp‐type signal, (...Figure 3.15 Geometry for synthetic aperture radar (SAR).Figure 3.16 (a) Actual radial distance (drawn as solid line) and estimated r...Figure 3.17 Spotlight SAR with a circular flight path.Figure 3.18 Flowchart of RDA.Figure 3.19 (a) A typical chirp signal waveform, (b) time‐frequency display ...Figure 3.20 Hanning windowed range‐compressed signal.Figure 3.21 SAR image generation example. (a) a scene with tank models, (b) ...Figure 3.22 SIR‐C/X‐SAR image of San Francisco, California.Figure 3.23 A simplified MOCOMP geometry for SAR.Figure 3.24 Geometry for InSAR.Figure 3.25 (SIR‐C/X‐SAR) Interferometric image of Mount Etna, Italy.htt...Figure 3.26 Polarimetric SAR image of Southeast Oahu, HI.(For the whole ...

4 Chapter 4Figure 4.1 Inverse synthetic aperture radar (ISAR) geometry.Figure 4.2 Spotlight SAR geometry with circular flight path is analogous to ...Figure 4.3 SAR‐to‐ISAR transition: (a) spotlight SAR with circular flight pa...Figure 4.4 Spotlight SAR with straight flight path.Figure 4.5 Range profile of a target.Figure 4.6 Range profile of a model airplane.Figure 4.7 Collecting radar returns at different look angles to form the cro...Figure 4.8 Cross‐range profile of a model airplane.Figure 4.9 (a) Collection of ISAR raw data in Fourier space for the monostat...Figure 4.10 Geometry for monostatic ISAR imaging (2D case).Figure 4.11 Geometry for imaging multibounce mechanisms in ISAR.Figure 4.12 (a) Single‐bounce mechanisms are correctly mapped in ISAR. (b) M...Figure 4.13 All double bounces from a 90° corner reflector have the same tra...Figure 4.14 ISAR image of a 1 m × 1 m corner reflector at 10 GHz. The images...Figure 4.15 ISAR image of a plane model from 45° from the nose on. Some mult...Figure 4.16 Flowchart for the basic ISAR imaging algorithm.Figure 4.17 (a) CAD view of a fighter plane, (b) ISAR simulation scenario fo...Figure 4.18 2D ISAR images of the fighter model for (a) VV‐polarization, and...Figure 4.19 (a) CAD view of a military tank model, and (b) ISAR simulation s...Figure 4.20 2D ISAR images of the military tank model for (a) VV‐polarizatio...Figure 4.21 The locations of point scatterers around a fictitious airplane....Figure 4.22 Small‐bandwidth small‐angle ISAR image of the hypothetical airpl...Figure 4.23 Aliased ISAR image after applying a 2D IFT to a wide‐bandwidth l...Figure 4.24 Wide‐bandwidth large‐angle ISAR image of the airplane‐like geome...Figure 4.25 Rectangular reformatting of polar ISAR data.Figure 4.26 The backscattered field data in frequency‐aspect domain.Figure 4.27 The backscattered field data on spatial frequency plane of k_x–k_yFigure 4.28 Wide‐bandwidth large‐angle ISAR image of the airplane‐like geome...Figure 4.29 Collection of raw ISAR data in Fourier space (3D monostatic case...Figure 4.30 Geometry for monostatic ISAR imaging (3D case).Figure 4.31 (a) CAD view of a bomber airplane, (b) 3D ISAR simulation scenar...Figure 4.32 2D ISAR(x, y) slices for different z values of the 3D ISAR image...Figure 4.33 2D projections of the 3D ISAR image of the airplane model on (a)...

5 Chapter 5Figure 5.1 Digitizing process: (a) original continuous time signal, (b) obse...Figure 5.2 Demonstration of positive and negative frequencies in DFT: first ...Figure 5.3 (a) The image window is periodic in range and cross‐range axes, (...Figure 5.4 An example of aliased ISAR image.Figure 5.5 Interpolation can be employed in different ways to reformat the p...Figure 5.6 First‐order nearest‐neighbor interpolation (3D case): eight neare...Figure 5.7 Second‐order nearest‐neighbor interpolation (2D case): 16 nearest...Figure 5.8 Implementation of bilinear interpolation (2D case).Figure 5.9 Illustration of interpolation with zero padding: (a) a rectangula...Figure 5.10 Interpolation using zero padding: (a) original ISAR images, (b) ...Figure 5.11 The physical meaning of PSF: (a) point scatterers, (b) the PSF, ...Figure 5.12 (a) Rectangular window, (b) spectrum of rectangular window.Figure 5.13 (a) Triangular window, (b) spectrum of triangular window.Figure 5.14 (a) Hanning window, (b) spectrum of Hanning window.Figure 5.15 (a) Hamming window, (b) spectrum of Hamming window.Figure 5.16 (a) Kaiser window, (b) spectrum of Kaiser window.Figure 5.17 (a) Blackman window, (b) spectrum of Blackman window.Figure 5.18 (a) Chebyshev window, (b) spectrum of Chebyshev window.Figure 5.19 Effect of using smoothing windows: (a) original ISAR images, (b)...

6 Chapter 6Figure 6.1 For the ISAR operation, the aspect diversity is constituted targe...Figure 6.2 Resulting 2D ISAR images for (a) pitching, (b) yawing (turning), ...Figure 6.3 The formation of the ISAR grid for a maneuvering platform.Figure 6.4 The chirp pulse train is utilized in range‐Doppler processing of ...Figure 6.5 Representation of stepped frequency transmitted signal of M burst...Figure 6.6 Target's rotational motion causes Doppler shift in the frequency ...Figure 6.7 Geometry for Doppler processing of a rotating target.Figure 6.8 ISAR receiver block diagram for chirp pulse illumination.Figure 6.9 ISAR receiver block diagram for stepped frequency radar illuminat...Figure 6.10 Block diagram for quadrature detection.Figure 6.11 Formation of the range‐Doppler ISAR image via digital processing...Figure 6.12 Selection of image frame size and resolutions in ISAR imaging.Figure 6.13 The scenario for range‐Doppler ISAR imaging.Figure 6.14 Fictitious fighter consists of perfect point scatterers of equal...Figure 6.15 Transmitted chirp pulse waveform.Figure 6.16 Matched filter response of the chirp pulse.Figure 6.17 Range compressed data with additive random noise are present.Figure 6.18 Range‐Doppler ISAR image of the target with additive random nois...Figure 6.19 Range cross‐range ISAR image of the target with additive random ...Figure 6.20 A geometry for ISAR imaging scenario.Figure 6.21 Target with perfect point scatterers.Figure 6.22 Range profiles of the target for different burst indexes.Figure 6.23 Range‐Doppler ISAR image of the target.

7 Chapter 7Figure 7.1 Point‐radiator model of the scattered field. (a) the real scenari...Figure 7.2 The biplane model in ISAR simulation. (a) front, side and top vie...Figure 7.3 Original ISAR image of the biplane target displayed with CAD mode...Figure 7.4 (a) Locations of extracted scattering centers in range – cross‐ra...Figure 7.5 Reconstructed ISAR image of the biplane target based on CLEAN alg...Figure 7.6 (a) Original backscattered electric‐ field for the ISAR example i...Figure 7.7 Reconstructed backscattered field patterns sampled 5 times more c...Figure 7.8 Comparison of the original pattern obtained by brute‐force comput...Figure 7.9 Comparison of the original pattern obtained by brute‐force comput...Figure 7.10 (a) Amplitudes of the extracted scattering centers based on Four...Figure 7.11 2D backscattered electric field data: (a) Original, (b) Reconstr...Figure 7.12 Reconstructed field pattern (5 times more sampled) gives more de...Figure 7.13 Comparison of the original pattern obtained by brute‐force compu...Figure 7.14 2D ISAR image: (a) Original, (b) Reconstructed after utilizing 2...

8 Chapter 8Figure 8.1 Geometry for a moving target with respect to radar.Figure 8.2 A fighter target composed of perfect point scatterers.Figure 8.3 Traditional ISAR image of the fighter target (no compensation).Figure 8.4 Range profile shifts and their smoothened versions versus range p...Figure 8.5 (a) Range differences with respect range profile index, and (b) r...Figure 8.6 Motion‐compensated ISAR image of the fighter target.Figure 8.7 A hypothetical target composed of perfect point scatterers.Figure 8.8 Conventional ISAR image of the airplane target (no compensation)....Figure 8.9 Spectrogram of range cells (before compensation).Figure 8.10 Entropy plot for translational radial velocity translational rad...Figure 8.11 ISAR image of the airplane after applying minimum entropy compen...Figure 8.12 Spectrogram of range cells (after compensation).Figure 8.13 Schematic representation of JTF‐based ISAR imaging system.Figure 8.14 (a) A target (consists of perfect point scatterers) moving with ...Figure 8.15 2D range‐cross range ISAR images for different time snapshots (i...Figure 8.16 Conventional ISAR image of the airplane target with translationa...Figure 8.17 Spectrogram of range cells (no compensation).Figure 8.18 2D Matching pursuit search space for the translational velocity ...Figure 8.19 ISAR image of the airplane target after translational motion com...Figure 8.20 Spectrogram of time pulses (after translational compensation).Figure 8.21 ISAR image of the airplane target after translational and rotati...Figure 8.22 Spectrogram of time pulses (after translational and rotational m...

9 Chapter 9Figure 9.1 (a) Monostatic ISAR versus, (b) Bi‐ISAR imaging configuration.Figure 9.2 (a) Monostatic radar can only sense backscattered wave, (b) bista...Figure 9.3 Geometry for bistatic ISAR imaging.Figure 9.4 Flowchart for the Bi‐ISAR imaging algorithm.Figure 9.5 (a) Bi-ISAR imaging geometry for an airplane model, (b) construct...Figure 9.6 Fighter aircraft model for the Bi-ISAR imaging example #2.Figure 9.7 Bi‐ISAR image of the aircraft model for bistatic angle of (a) 20°...Figure 9.8 Various geometries for Mu‐ISAR imaging configurations: (a) single...Figure 9.9 Multi‐static ISAR scenario with single transmitter and three rece...Figure 9.10 Fighter craft modeled with perfect point scatterers.Figure 9.11 Bi‐ISAR images of aircraft model obtained at (a) Rx #1, (b) Rx #...

10 Chapter 10Figure 10.1 Polarization ellipse of an EM wave.Figure 10.2 The basic system architecture for a LP polarized radar transceiv...Figure 10.3 Scattering characteristics of EM wave from (a) an urban area, an...Figure 10.4 Pauli RBG color palette with scattering explanations. (For whole...Figure 10.5 SLICY target in ISAR simulation for the look‐aspect direction of...Figure 10.6 LP‐ISAR images of the “SLICY” target for the radar look directio...Figure 10.7 Illustration of various scattering mechanisms from the “SLICY” t...Figure 10.8 CP‐ISAR images of the “SLICY” target for the radar look directio...Figure 10.9 Pauli image of SLICY for the radar look direction of (θⁱ = ...Figure 10.10 Military Tank model: side, front, and top views with dimensions...Figure 10.11 Military Tank target in ISAR simulation for the look‐aspect dir...Figure 10.12 LP‐ISAR images of the “Military Tank” target for the radar look...Figure 10.13 CP‐ISAR images of the “Military Tank” target for the radar look...Figure 10.14 Pauli images of the “Military Tank” target for the radar look d...Figure 10.15 Various scattering mechanism from different parts of Military T...

11 Chapter 11Figure 11.1 Geometry for determination of far‐ and near‐field regions of a r...Figure 11.2 Geometry for 3D near‐field ISAR imaging.Figure 11.3 Geometrical explanation of Fourier slice theorem.Figure 11.4 Geometry for 2D near‐field ISAR imaging.Figure 11.5 A set of point targets used in near‐field ISAR simulation.Figure 11.6 Numerically collected backscattered electric field in (a) f–ϕ...Figure 11.7 ISAR images for the point targets in Figure 11.5 by applying (a)...Figure 11.8 (a) Back‐hoe loader target, (b) a scene from the measurement, an...Figure 11.9 2D near‐field ISAR image of back‐hoe loader target (a) standard ...Figure 11.10 A scene from the 2D near‐field ISAR imaging measurement.Figure 11.11 Anechoic chamber geometry for 2D near‐field imaging of a small‐...Figure 11.12 2D near‐field ISAR image of hand‐gun target using (a) focusing ...

12 Chapter 12Figure 12.1 Geometry for the GPR problem. (a) monostatic scenario, (b) bista...Figure 12.2 (a) Geometry for the A‐scan GPR measurement, (b) example of a me...Figure 12.3 (a) Geometry for the B‐scan GPR measurement, (b) example of a me...Figure 12.4 (a) Geometry for the C‐scan GPR measurement, (b) a measured exam...Figure 12.5 Geometry for (a) the stripmap SAR problem, (b) the B‐scan GPR pr...Figure 12.6 Flow chart representation of SAR based ω‐k migration algori...Figure 12.7 (a) Configuration of two closely placed pipes buried in sand med...Figure 12.8 The B‐scan GPR geometry for the BPA formulation.Figure 12.9 Flow chart representation of SAR based filtered BPA.Figure 12.10 Focused image after SAR based BPA.Figure 12.11 A typical application geometry for TWIR.Figure 12.12 SAR set‐up for TWIR problem. (a) with linear array antennas, an...Figure 12.13 An example of SAR‐based TWIR application. (a) measurement geome...Figure 12.14 (a) The pattern of a typical stand‐alone antenna, (b) The patte...Figure 12.15 (a) The conventional ISAR scenario based on two‐way EM backscatt...Figure 12.16 The path of the radiated signal which is scattered off a point ...Figure 12.17 An example showing the effect of the u‐to‐x transformation. (a)...Figure 12.18 (a) Aircraft's CAD model used for ASAR imaging example. (b) The...Figure 12.19 2D ASAR image slices in the x − y plane for different z cuts.Figure 12.20 2D projected ASAR image obtained by summing up all z – slices....Figure 12.21 (a) The conventional ISAR scenario based on two‐way EM backscat...Figure 12.22 Conceptual comparison of different radar imaging scenarios.Figure 12.23 The geometry for ACSAR imaging.Figure 12.24 The geometry for generating the ACSAR image of a ship‐like plat...Figure 12.25 2D projected ACSAR images of a ship platform in (a) R − u plane...Figure 12.26 2D projected ACSAR images of a ship platform. (a) projected y −...Figure 12.27 Applying ACSAR approach to the GPR problem.Figure 12.28 2D projected ACSAR images of buried bottle beneath the sand sur...