Preface ........................................................ xv
Introduction ..................................................xvii
1 Target Identification, Measurement Requirements, and
Algorithms ................................................... 1
1.1 Background .............................................. 1
1.1.1 Two-Dimensional Target Imaging and Complex-
Image Analysis ................................... 1
1.1.2 Intensity Images Versus Complex Images ........... 4
1.1.3 Backscattering Behavior of Man-Made Targets ...... 6
1.1.4 Measurement Methods of Complex-Image Analysis
Technology ...................................... 10
1.1.5 Section Summary ................................. 28
1.2 Identification Principles .............................. 30
1.2.1 Derivation of a Practical Approach to Target
Identification .................................. 30
1.2.2 Wavelength and Resolution in Identification
Performance ..................................... 36
1.2.3 Section Summary ................................. 40
1.3 Measurement of Range and Crossrange: The Two-
Scatterer Algorithm .................................... 40
1.3.1 Resolution Principles ........................... 41
1.3.2 Implementation of the TSA for Ideal Point
Targets ......................................... 53
1.3.3 Application to Real Data ....................... 632
1.3.4 Section Summary ................................. 76
1.4 Special Measurements of Potential Use .................. 77
1.4.1 Feature Extent .................................. 77
1.4.2 Cross Section of Features ....................... 80
1.4.3 Polarization Diversity .......................... 80
1.4.4 Dispersive Backscattering ....................... 82
1.5 Identification Procedure ............................... 82
1.5.1 Recognizable Target Features .................... 83
1.5.2 Deformable Template Match ....................... 84
1.5.3 The Identification Process ...................... 86
References .................................................. 86
2 Topics Related to Target Identification ..................... 89
2.1 Ambiguity Function, Resolution, and Superresolution .... 89
2.1.1 Use of the Ambiguity Function ................... 90
2.1.2 One-Dimensional Resolution ...................... 91
2.1.3 Superresolution ................................. 96
2.1.4 Two-Dimensional Resolution ...................... 98
2.1.5 Resolution of Weak Scatterers from Strong
Scatterers ...................................... 99
2.1.6 Effects of Weighting for Sidelobe
Suppression .................................... 100
2.1.7 Resolution and Shifting Scatterers ............. 102
2.1.8 Section Summary ................................ 103
2.2 Asymmetry of Range and Crossrange Resolution .......... 104
2.2.1 Resolution Requirements for Target
Identification ................................. 105
2.2.2 Measurement of Feature Positions ............... 105
2.2.3 Fully Utilizing the Available Range
Resolution ..................................... 107
2.2.4 The Real Situation and Requirements on
Crossrange Resolution .......................... 110
2.2.5 Illustration with Real Data .................... 111
2.2.6 Checking the Limit on Crossrange Resolution .... 117
2.2.7 Crossrange Resolution for Targets at
Broadside Aspects .............................. 121
2.2.8 Section Summary ................................ 121
2.3 Imaging Moving Targets ................................ 122
2.3.1 Imaging Principles ............................. 122
2.3.2 Motion Compensation ............................ 125
2.3.3 Motion Determination ........................... 156
2.3.4 Section Summary ................................ 158
2.4 The Need For Adaptive Processing Methods .............. 159
References ................................................. 161
3 Aircraft Identification .................................... 163
3.1 Significance of the Radar Waveform .................... 163
3.1.1 Section Summary ................................ 163
3.2 Identification via Range Profiles ..................... 168
3.2.1 Requirements on Range Profiles for
Identification ................................. 169
3.2.2 Range Profiles Without Duct Returns ............ 170
3.2.3 Delayed Duct Returns ........................... 175
3.2.4 Range Profiles Containing Skin Returns and
Delayed Duct Returns ........................... 177
3.2.5 Conclusions About Range Profile Utility ........ 179
3.2.6 Section Summary ................................ 181
3.2.5 Theory and Practice of Radar Target
Identification ................................. 179
3.3 Identification via ISAR Imagery ....................... 181
3.4 Aircraft Features for Identification .................. 182
3.4.1 Special Aircraft Features ...................... 182
3.4.2 Features Common to All Aircraft ................ 186
3.4.3 Deriving the Database .......................... 191
3.4.4 Section Summary ................................ 198
3.5 Resolution Requirements ............................... 199
3.6 Imaging of Aircraft ................................... 203
3.6.1 Aircraft Imaging Principles .................... 204
3.6.2 Illustrations of Aircraft Imaging Without
Delayed Duct Returns ........................... 209
3.6.3 Illustrations of Aircraft Imaging With
Delayed Duct Returns ........................... 223
3.6.4 Imaging of Maneuvering Aircraft ................ 229
3.6.5 Maneuvering Combined With Vibrations ........... 239
3.6.6 Imaging at Large Aspect Angles ................. 245
3.6.7 The Special Case of Zero Aspect Angle .......... 266
3.6.8 The Special Case of a 180° Aspect Angle ........ 273
3.6.9 Imaging and Identification of Large
Commercial Aircraft ............................ 277
3.6.10 Section Summary ................................ 282
3.7 Example of Positional Match for a Correct and
Incorrect Aircraft .................................... 283
3.8 Procedure for Automated Aircraft Identification ....... 285
3.8.1 Step 1: Data Collection ........................ 285
3.8.2 Step 2: Compensation and Selection of the
Imaging Interval ............................... 288
3.8.3 Step 3: Image Analysis ......................... 289
3.8.4 Step 4: Identification ......................... 290
References ................................................. 290
4 Ground Vehicle Identification .............................. 291
4.1 Variability of Conditions for Identification .......... 291
4.1.1 Application 1: Radar Platform and Ground
Vehicles Stationary ............................ 292
4.1.2 Application 2: Radar Platform Stationary,
Ground Vehicles Moving ......................... 292
4.1.3 Application 3: Radar Platform Moving, Ground
Vehicles Stationary ............................ 293
4.1.4 Application 4: Radar Platform Moving, Ground
Vehicles Moving ................................ 294
4.1.5 Section Summary ................................ 296
4.2 Basics of Ground Vehicle Identification ............... 296
4.2.1 Radar Features Versus Vehicle Design
Features ....................................... 297
4.2.2 Recognizable Features .......................... 298
4.2.3 Positions of Unrecognizable Features ........... 300
4.2.4 Section Summary ................................ 300
4.3 Identification of Stationary Ground Vehicles .......... 300
4.3.1 Example 1: Measurements and Characterization
for a Howitzer ................................. 301
4.3.2 Example 2: Measurements and Characterization
for a Tank ..................................... 314
4.3.3 Example 3: Measurements and Characterization
for an Off-Highway Truck ....................... 320
4.3.4 Example 4: Measurements and Characterization
for a Flatbed Truck ............................ 326
4.3.5 Assisting the Positional Match ................. 331
4.3.6 Section Summary ................................ 336
4.4 Identification of Moving Ground Vehicles .............. 336
4.4.1 Peculiarities of Moving Ground Vehicle
Identification ................................. 337
4.4.2 Consequences of Different Types of Motion ...... 338
4.4.3 General Processing Procedures .................. 340
4.4.4 A Moving Off-Highway Truck ..................... 347
4.4.5 The Tank Moving in a Circle on Terrain ......... 377
4.4.6 The Flatbed Truck on a Bumpy Straight Road ..... 384
4.4.7 Recreational Vehicle Turning on a Paved
Surface ........................................ 389
4.4.8 Procedure for Analyzing the Survey Image
and Forming a Final Image ...................... 409
4.4.9 More Sophisticated Motion Compensations ........ 417
4.4.10 Procedure for Automated Identification of
Moving Ground Vehicles ......................... 428
4.4.11 Section Summary ................................ 431
References ................................................. 432
5 Identification of Ships .................................... 433
5.1 Basics of Ship Identification ......................... 433
5.1.1 Peculiarities of Ship Identification ........... 433
5.1.2 Imaging of Ships ............................... 434
5.1.3 Image-Time Selection ........................... 447
5.1.4 Principles of Analyzing a Ship's Motion ........ 452
5.1.5 Motion Analysis for Real Data .................. 467
5.1.6 Section Summary ................................ 473
5.2 Illustrations of the Measurement of Yaw and
Roll Motions .......................................... 474
5.2.1 Measurement Principles for Real Data ........... 474
5.2.2 Significant Roll ............................... 477
5.2.3 Very Little Roll Motion ........................ 504
5.2.4 Turn Maneuver .................................. 510
5.2.5 Dive Boat at the End of a Turn ................. 517
5.2.6 Small Ship in Rough Seas ....................... 523
5.2.7 Section Summary ................................ 543
5.3 Analysis of Ship Images ............................... 545
5.3.1 Measurement of Ship Length and Width ........... 546
5.3.2 Scatterer Positions on Deck and Shape of
Deck ........................................... 569
5.3.3 Height of Scatterers Above Deck (Shape of
Superstructure) ................................ 570
5.3.4 Section Summary ................................ 575
5.4 Processing Steps for Ship Identification/
Classification ........................................ 576
5.4.1 Step 1: Analysis of the Ship's Motion .......... 576
5.4.2 Step 2: Selection of Imaging Time and
Duration ....................................... 577
5.4.3 Step 3: Motion Compensation .................... 578
5.4.4 Step 4: Identification/Classification .......... 579
6 Analyzing Missiles, Rockets, and Satellites ................ 581
6.1 Overview .............................................. 581
6.1.1 Section Summary ................................ 585
6.2 Basic Approach to Enhanced Sliding-Window Doppler
Processing ............................................ 585
6.2.1 Section Summary ................................. 589
6.3 Analysis of an Attitude Maneuver ...................... 590
6.3.1 Section Summary ................................ 610
6.4 Analysis of the Smooth Flight ......................... 611
6.4.1 Section Summary ................................ 618
6.5 Signal Sections and Response Groups ................... 619
6.5.1 Section Summary ................................ 625
6.6 Chapter Summary ....................................... 625
Appendix A:
One-Dimensional Two-Scatterer Algorithm .................... 627
Appendix B:
Transform Window Limits .................................... 641
Reference .................................................. 645
Appendix C:
Determining Scatterer Separations in Range Gates
With Residual Uncompensated Motion ......................... 647
Appendix D:
Errors in Estimating Times of Two-Dimensional Motion ....... 659
Reference .................................................. 663
Appendix E:
Extracting Scatterer Locations From Range Tracks ........... 665
Reference .................................................. 670
Appendix F:
Modifications to the TSA for Interactive
Two-Dimensional Analysis ................................... 671
References ................................................. 689
Appendix G:
Tracking Interfering Scatterers by Measuring Phase
Slopes ..................................................... 691
G.l Introduction .......................................... 691
G.2 Choosing Intervals for Phase-Slope Measurement ........ 692
G.3 Data Analysis ......................................... 695
G.4 Summary ............................................... 703
Appendix H:
Setting an Amplitude Threshold for Analyzing Image
Responses .................................................. 705
Reference .................................................. 711
About the Authors ............................................. 713
Index ......................................................... 715
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