Radar Techniques Using Array Antennas

558 Pages·2013·32.81 MB·English

by  Wulf-Dieter Wirth

IET RADAR,SONAR AND NAVIGATIONSERIES 26
Radar Techniques
Using Array
Antennas
Othervolumesinthisseries:
Volume1 OptimisedradarprocessorsA.Farina(Editor)
Volume3 WeibullradarclutterM.SekineandY.Mao
Volume7 Ultra-widebandradarmeasurements:analysisandprocessing
L.Yu.AstaninandA.A.Kostylev
Volume8 Aviationweathersurveillancesystems:advancedradarandsurface
sensorsforflightsafetyandairtrafficmanagementP.R.Mahapatra
Volume10 RadartechniquesusingarrayantennasW.Wirth
Volume11 Airandspaceborneradarsystems:anintroductionP.Lacomme(Editor)
Volume13 IntroductiontoRFstealthD.Lynch
Volume14 Applicationsofspace-timeadaptiveprocessingR.Klemm(Editor)
Volume15 Groundpenetratingradar,2ndeditionD.Daniels
Volume16 TargetdetectionbymarineradarJ.Briggs
Volume17 Strapdowninertialnavigationtechnology,2ndeditionD.Tittertonand
J.Weston
Volume18 IntroductiontoradartargetrecognitionP.Tait
Volume19 RadarimagingandholographyA.PasmurovandS.Zinovjev
Volume20 Seaclutter:scattering,theKdistributionandradarperformanceK.Ward,
R.ToughandS.Watts
Volume21 Principlesofspace-timeadaptiveprocessing,3rdeditionR.Klemm
Volume22 WaveformdesignanddiversityforadvancedradarsystemsF.Gini,
A.DeMaio,L.K.Patton
Volume23 Filterengineering:theGauss-NewtonandpolynomialfiltersN.Morrison
Volume101 Introductiontoairborneradar,2ndeditionG.W.Stimson
Radar Techniques
Using Array
Antennas
2nd Edition
Wulf-Dieter Wirth
The Institution ofEngineeringand Technology
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Firstpublished2001
Secondedition2013
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Contents
Preface xv
Preface tothe2ndedition xviii
Abbreviations xix
Symbols xxiii
1 Introduction 1
2 Signalrepresentation andmathematical tools 5
2.1 Vectors, matrices 5
2.2 Computing with matrices 6
2.2.1 Addition and subtraction 6
2.2.2 Multiplication 6
2.2.3 Identity matrix 8
2.2.4 Inverse matrix 8
2.2.5 Eigenvalue decomposition 9
2.2.6 QRdecomposition 9
2.3 Fourier transform 10
2.3.1 Fast Fourier transform 11
2.4 Filter in the frequency and time domain 11
2.5 Correlation 14
2.6 Wiener–Khintchine theorem 15
References 16
3 Statistical signal theory 17
3.1 The general tasks of signal processing 17
3.2 Introduction to basics of statistics 18
3.2.1 Probabilitiesfordiscrete random variables 19
3.2.2 Continuousrandom variables 21
3.2.3 Functions of random variables 24
3.2.4 Statistical averages 28
3.2.5 Correlation 30
3.2.6 Gaussian densityfunction 30
3.2.7 Correlated Gaussian variables 31
3.2.8 Complex Gaussian variables 33
3.3 Likelihood-ratio test 33
viii Radar techniques usingarray antennas
3.4 Parameter estimation 39
3.4.1 Variance of the estimate and Crame´r–Rao limit 39
3.5 Estimationof a signal 44
3.5.1 Maximum-likelihood estimation 44
3.5.2 Signal estimation with least mean-square error 44
3.5.3 Interference suppressionby the inverse covariance 45
3.5.4 Improvement of signal-to-noise-and-interference
ratio (SNIR) 47
3.6 Summary 48
References 48
4 Array antennas 49
4.1 Array factor 50
4.2 Array parameters 55
4.2.1 Half-power beamwidth 55
4.2.2 Bandwidth limitation with phase steering 56
4.2.3 Antenna element spacingwithout grating lobes 57
4.2.4 Gain of regular-spacedplanar arrays with d¼l/2 58
4.2.5 Reduction of sidelobes bytapering 59
4.3 Circular array 61
4.4 Phase and amplitude errors 63
4.5 Architectures of passive and active array antennas 68
4.5.1 Comparison of efficiency for active and passive array 72
4.5.2 Radar equation foractive arrays 73
4.6 Conceptsforan extended field of view 73
4.6.1 Volume array for complete azimuth coverage 74
4.7 Monitoring of phased array antennas 78
4.7.1 Antenna measurement 78
4.7.2 Transmit/receive module (TRM)monitoring 78
4.8 Appendix: Taylor and Bayliss weighting 80
References 82
5 Beamforming 85
5.1 Single receiving beam 87
5.1.1 RF-beamforming 87
5.1.2 Subarrays and partial digital beamforming 87
5.1.3 Dynamic range requirements 89
5.1.4 Subarray configuration for digital sum and difference
beamforming 90
5.1.5 Correctionof antenna failures 94
5.1.6 Digital beamforming at element level 95
5.2 Broad band beamforming 95
5.3 Multiple beams 99
5.3.1 RFmultiple beamforming 100
5.3.2 RF-multiple beamforming usingsubarrays 101
Contents ix
5.3.3 IFmultiple beamforming bya resistive network 102
5.3.4 Baseband multiple beamforming 102
5.3.5 Time-multiplex beamforming for arbitrary directions 102
5.3.6 Digital multiple beamforming usingsubarrays 102
5.3.7 Multiple beam cluster for target search 104
5.3.7.1 Fanbeam fortransmittingandreceiving 104
5.3.7.2 Fanbeam fortransmittingandaclusterof
pencil beamsforreceiving 105
5.4 Deterministic spatial filtering 105
5.5 Compressed sensingfor beamforming 107
References 111
6 Sampling anddigitisationof signals 113
6.1 Analytical signal 113
6.2 Sampling and interpolation 116
6.3 Extraction of the componentsI and Qin digital format 118
6.4 Third-order intercept point and dynamic range 125
References 127
7 Pulse compression withpolyphasecodes 129
7.1 Introduction 129
7.2 Requirements and basic structure for pulse compression 130
7.3 Binary phase codes 131
7.4 Polyphase code as an approximation of linear
frequency modulation 132
7.5 Reduction of range sidelobes 138
7.5.1 Application of a weighting function 138
7.5.2 Application of a mismatched LS filter 139
7.5.3 Application of an estimation filter 142
7.6 Reduction of sidelobes by a phase code from nonlinear
frequency modulation 142
7.7 Complementarycodes 147
7.8 Polyphase code with periodic repetition 148
7.9 Pulseeclipsing 150
7.10 High range resolution by oversampling and LS
pulse compression 151
7.10.1 Calculation of the filter function forthe
pulse compression 152
7.10.2 Subpulse filter 152
7.10.3 Gain or S/Nloss 153
7.10.4 Pulse compression of simulated signals 153
7.10.5 Compression of measured echo signals 155
7.11 Conclusions 157
References 158