Radar Techniques Using Array Antennas

Radar Techniques
Using Array
Antennas,
2nd Edition......Page 4
Contents......Page 8
Preface......Page 16
Preface to the 2nd edition......Page 19
Abbreviations......Page 20
Symbols......Page 24
1 Introduction......Page 28
2.1 Vectors, matrices......Page 32
2.2.2 Multiplication......Page 33
2.2.4 Inverse matrix......Page 35
2.2.6 QR decomposition......Page 36
2.3 Fourier transform......Page 37
2.4 Filter in the frequency and time domain......Page 38
2.5 Correlation......Page 41
2.6 Wiener–Khintchine theorem......Page 42
References......Page 43
3.1 The general tasks of signal processing......Page 44
3.2 Introduction to basics of statistics......Page 45
3.2.1 Probabilities for discrete random variables......Page 46
3.2.2 Continuous random variables......Page 48
3.2.3 Functions of random variables......Page 51
3.2.4 Statistical averages......Page 55
3.2.6 Gaussian density function......Page 57
3.2.7 Correlated Gaussian variables......Page 58
3.3 Likelihood-ratio test......Page 60
3.4.1 Variance of the estimate and Cramér–Rao limit......Page 66
3.5.2 Signal estimation with least mean-square error......Page 71
3.5.3 Interference suppression by the inverse covariance......Page 72
3.5.4 Improvement of signal-to-noise-and-interference ratio (SNIR)......Page 74
References......Page 75
4 Array antennas......Page 76
4.1 Array factor......Page 77
4.2.1 Half-power beamwidth......Page 82
4.2.2 Bandwidth limitation with phase steering......Page 83
4.2.3 Antenna element spacing without grating lobes......Page 84
4.2.4 Gain of regular-spaced planar arrays with d=λ/2......Page 85
4.2.5 Reduction of sidelobes by tapering......Page 86
4.3 Circular array......Page 88
4.4 Phase and amplitude errors......Page 90
4.5 Architectures of passive and active array antennas......Page 95
4.5.1 Comparison of efficiency for active and passive array......Page 99
4.6 Concepts for an extended field of view......Page 100
4.6.1 Volume array for complete azimuth coverage......Page 101
4.7.2 Transmit/receive module (TRM) monitoring......Page 105
4.8 Appendix: Taylor and Bayliss weighting......Page 107
References......Page 109
5 Beamforming......Page 112
5.1.2 Subarrays and partial digital beamforming......Page 114
5.1.3 Dynamic range requirements......Page 116
5.1.4 Subarray configuration for digital sum and difference
beamforming......Page 117
5.1.5 Correction of antenna failures......Page 121
5.2 Broad band beamforming......Page 122
5.3 Multiple beams......Page 126
5.3.1 RF multiple beamforming......Page 127
5.3.2 RF-multiple beamforming using subarrays......Page 128
5.3.6 Digital multiple beamforming using subarrays......Page 129
5.3.7.1 Fan beam for transmitting and receiving......Page 131
5.4 Deterministic spatial filtering......Page 132
5.5 Compressed sensing for beamforming......Page 134
References......Page 138
6.1 Analytical signal......Page 140
6.2 Sampling and interpolation......Page 143
6.3 Extraction of the components I and Q in digital format......Page 145
6.4 Third-order intercept point and dynamic range......Page 152
References......Page 154
7.1 Introduction......Page 156
7.2 Requirements and basic structure for pulse compression......Page 157
7.3 Binary phase codes......Page 158
7.4 Polyphase code as an approximation of linear
frequency modulation......Page 159
7.5.1 Application of a weighting function......Page 165
7.5.2 Application of a mismatched LS filter......Page 166
7.6 Reduction of sidelobes by a phase code from nonlinear
frequency modulation......Page 169
7.7 Complementary codes......Page 174
7.8 Polyphase code with periodic repetition......Page 175
7.9 Pulse eclipsing......Page 177
7.10 High range resolution by oversampling and
LS pulse compression......Page 178
7.10.2 Subpulse filter......Page 179
7.10.4 Pulse compression of simulated signals......Page 180
7.10.5 Compression of measured echo signals......Page 182
7.11 Conclusions......Page 184
References......Page 185
8 Detection of targets by a pulse series......Page 188
8.1 Filter against fixed clutter......Page 190
8.2 Doppler filter processor......Page 193
8.3 Adaptive suppression of weather clutter......Page 195
8.3.1 Computation of the gain......Page 198
8.3.2 Evaluation of experimental signals......Page 199
8.4 Suppression of sea clutter......Page 204
8.5 Estimation of Doppler frequency......Page 205
8.5.1 Accuracy of Doppler estimation by Cramér–Rao bound......Page 207
8.5.2 Simplified Doppler estimator......Page 210
8.6.1 Variable Doppler frequency of the target signal......Page 211
8.6.2 Coherent test function for long echo series......Page 213
8.6.3 Comparison of detection performance of the filter bank and
ACE-test for LFM Doppler signals......Page 216
References......Page 217
9 Sequential detection......Page 220
9.1 Incoherent detection......Page 222
9.2.2 Common test for all range elements......Page 223
9.2.3 Combined test with range-dependent design signal......Page 224
9.2.4 Comparison of the test for multiple range cells with
the fixed sample size test......Page 225
9.3 Coherent test function......Page 227
9.3.1 Test function with autocorrelation estimates......Page 228
9.3.2 Sequential test function with autocorrelation estimates......Page 230
9.3.3 Simulation studies for a comparison of incoherent and
coherent sequential tests......Page 233
9.3.5 Extension for multiple range elements......Page 237
9.4 Comparison of detection procedures......Page 240
9.5 Adaptation to the noise level and energy management......Page 241
9.6 Sequential test for long signal series......Page 242
9.6.1 Sequential test with coherent sections......Page 243
9.6.2 Simulation studies......Page 244
9.7 Experimental system......Page 247
9.8 Conclusions......Page 251
References......Page 252
10 Adaptive beamforming for jammer suppression......Page 254
10.1 Deterministic generation of pattern notches......Page 256
10.1.1 LMS weighting......Page 257
10.1.2 Multiple beam approach......Page 259
10.1.3 Limit for number of notches......Page 260
10.2.1 Optimal processing......Page 261
10.2.3 Orthogonalisation and eigenmatrix projection......Page 263
10.3 Antenna architecture for adaptation......Page 266
10.3.2 Adaptive beamforming with subarrays......Page 267
10.4.1 Sample matrix estimation......Page 268
10.4.2 Projection methods......Page 269
10.4.3 Channel errors......Page 272
10.4.4 Weighted projection: lean matrix inversion method......Page 275
10.5 Realisation aspects......Page 277
10.6 Experiments with the ELRA system......Page 278
10.7 Robustness against jammer motion......Page 283
10.8 Phase-only adaptive beamforming......Page 284
10.9 Conclusions......Page 285
References......Page 286
11.1 Likelihood direction estimation......Page 290
11.2 Experimental monopulse correction for failing elements......Page 295
11.3 Variance of monopulse estimate......Page 302
11.4.1 Correction with likelihood estimation......Page 304
11.4.2 Correction in expectation......Page 309
11.4.3 Statistical performance analysis of estimation......Page 314
11.5 Polarisation independence......Page 317
11.6 Indication of multiple targets......Page 318
References......Page 320
12.1 Introduction......Page 322
12.2 Parametric estimation......Page 323
12.3 Experimental verification of super-resolution......Page 333
12.4 Resolution by angular spectral estimation algorithms......Page 336
12.4.1 Resolution and the dimension of the signal subspace......Page 339
12.4.2 Estimation of the signal subspace dimension......Page 342
12.5 Expectation maximisation (EM) and space alternating
expectation maximisation (SAGE)......Page 343
12.6 Root-MUSIC......Page 346
12.7 ESPRIT procedure with least square (LS) and
total least square (TLS)......Page 347
12.7.1 Total least square procedure......Page 349
12.8 Experimental active receiving array system......Page 351
12.9 Error consequences......Page 352
12.10.1 Autocalibration for a uniform linear array......Page 353
12.10.2 Iterative algorithm for gain and phase calibration......Page 354
12.10.3 Angular ambiguity......Page 355
12.10.4 Experimental autocalibration......Page 358
12.10.5 Extension to calibration of mutual coupling......Page 360
12.10.6 Autocalibration for a volume array......Page 362
12.10.7 Estimation of antenna element position errors......Page 363
12.10.8 Experimental super-resolution in angle......Page 366
12.10.9 Autocalibration in case of multipath propagation......Page 367
12.11 Conclusions......Page 370
References......Page 371
13.2 Doppler-shifted clutter spectrum......Page 374
13.3 Space–time processing......Page 377
13.4 Necessary degrees of freedom......Page 380
13.5 Suboptimal concept with FIR filter: reduction
of time dimension......Page 381
13.6 Suboptimal concept with subarrays: reduction
of spatial dimension......Page 384
13.7 Adaptive processing......Page 389
References......Page 390
14.1 Basic principle of SAR......Page 392
14.2 Problems of moving-target detection and location......Page 397
14.3 Clutter suppression with multichannel array radar......Page 398
14.4 Target location......Page 405
14.5 SAR/MTI processing......Page 406
14.6 Jammer suppression......Page 408
14.7 Object height by interferometry......Page 409
14.8 Experimental system AER and results......Page 412
14.9 Summary and motivations for SAR with active
phased-array antennas......Page 416
References......Page 417
15.1 Introduction: basic principle......Page 420
15.2 Synthetic aperture and beam forming by target motion......Page 421
15.3 Target cross-range image......Page 423
15.4.1 Range focusing and range walk......Page 425
15.4.2 Focusing with straight-line assumption......Page 426
15.4.3.1 Iteration with Fourier transform and Kalman filter......Page 427
15.4.3.2 Doppler shift of a target and its scatterers......Page 428
15.4.3.3 Focusing with Wigner–Ville distribution......Page 431
15.5 High-range resolution......Page 435
15.6 Alternative image planes......Page 439
References......Page 440
16.1 Fluctuation effects......Page 442
16.2 Doppler spectrum evaluation......Page 445
References......Page 452
17.1 System overview......Page 454
17.2 Antenna parameter selection......Page 456
17.3 Antenna elements and modules......Page 459
17.4 Antenna control and monitoring......Page 461
17.5 Radar functions and waveforms of the ELRA system......Page 466
17.5.2 Time budget for a parameter example......Page 468
17.5.2.1 Search function......Page 469
17.6 Digital signal processing......Page 471
17.8 Control system, operation and display of functions
and results......Page 474
References......Page 479
18.1 Introduction......Page 482
18.2 The proposed OLPI concept......Page 483
18.4 The receiving system......Page 485
18.5 Resolution cell......Page 487
18.6 The phase code......Page 488
18.7 Signal processing......Page 489
18.8 Range performance......Page 491
18.9 Coherent and sequential test function with ACE......Page 492
18.10 OLPI and multifunction radar......Page 493
18.12 Detection and classification of hovering helicopters......Page 494
18.12.2 ISAR image and spectrum of rotor blades......Page 499
18.13 Spatial coding with a MIMO radar......Page 504
18.14 Summary and conclusions......Page 510
References......Page 511
19.1 Parameter selection for search and tracking......Page 514
19.1.1 Search period......Page 515
19.1.2 False-alarm probability......Page 518
19.1.3 Beam position separation......Page 519
19.1.4 Range resolution......Page 520
19.1.5 Tracking parameters......Page 521
19.2 Search procedure......Page 523
References......Page 524
20.1 Introduction......Page 526
20.2 Parameters and achievable range......Page 527
20.3 Signal description and resolution......Page 529
20.4.1 Adaptive beamforming......Page 532
20.4.2 Clutter cancellation......Page 533
20.4.3 Signal integration......Page 535
20.5 Reference signal......Page 538
20.6 Experimental results......Page 540
20.7 Tracking......Page 542
References......Page 544
Index......Page 546