Fundamentals of Radar Signal Processing

Home >
Browse >
Fundamentals of Radar Signal Processing

Fundamentals of Radar Signal Processing

Authors: Mark A. Richards

Published: June 2005

eISBN: 9780071776486 0071776486 | ISBN: 9780071444743

Contents

Preface

Acknowledgments

List of Symbols

List of Acronyms

Chapter 1. Introduction to Radar Systems

1.1 History and Applications of Radar

1.2 Basic Radar Functions

1.3 Elements of a Pulsed Radar

1.3.1 Transmitter and waveform generator

1.3.2 Antennas

1.3.3 Receivers

1.4 Review of Selected Signal Processing Concepts and Operations

1.4.1 Resolution

1.4.2 Spatial frequency

1.4.3 Fourier transforms

1.4.4 The sampling theorem and spectrum replication

1.4.5 Vector representation of signals

1.4.6 Data integration

1.4.7 Correlation

1.5 A Preview of Basic Radar Signal Processing

1.5.1 Radar time scales

1.5.2 Phenomenology

1.5.3 Signal conditioning and interference suppression

1.5.4 Imaging

1.5.5 Detection

1.5.6 Postprocessing

1.6 Radar Literature

1.6.1 Radar systems and components

1.6.2 Radar signal processing

1.6.3 Advanced radar signal processing

1.6.4 Current radar research

References

Chapter 2. Signal Models

2.1 Components of a Radar Signal

2.2 Amplitude Models

2.2.1 Simple point target radar range equation

2.2.2 Distributed target forms of the range equation

2.2.3 Radar cross section

2.2.4 Radar cross section for meteorological targets

2.2.5 Statistical description of radar cross section

2.2.6 Swerling models

2.3 Clutter

2.3.1 Behavior of σ[sup(0)]

2.3.2 Signal-to-clutter ratio

2.3.3 Temporal and spatial correlation of clutter

2.3.4 Compound models of radar cross section

2.4 Noise Model and Signal-to-Noise Ratio

2.5 Jamming

2.6 Frequency Models: The Doppler Shift

2.6.1 Doppler shift

2.6.2 Simplified approach to Doppler shift

2.6.3 The “stop-and-hop” assumption and spatial Doppler

2.7 Spatial Models

2.7.1 Variation with angle or cross-range

2.7.2 Variation with range

2.7.3 Projections

2.7.4 Multipath

2.8 Spectral Model

2.9 Summary

References

Chapter 3. Sampling and Quantization of Pulsed Radar Signals

3.1 Domains and Criteria for Sampling Radar Signals

3.1.1 Time and frequency samples

3.1.2 Spatial samples

3.1.3 Sampling criteria

3.2 Sampling in the Fast Time Dimension

3.3 Sampling in Slow Time: Selecting the Pulse Repetition Interval

3.4 Sampling the Doppler Spectrum

3.4.1 The Nyquist rate in Doppler

3.4.2 Straddle loss

3.5 Sampling in the Spatial and Angle Dimensions

3.5.1 Phased array element spacing

3.5.2 Antenna beam spacing

3.6 Quantization

3.7 I/Q Imbalance and Digital I/Q

3.7.1 I/Q imbalance and offset

3.7.2 Correcting I/Q errors

3.7.3 Digital I/Q

References

Chapter 4. Radar Waveforms

4.1 Introduction

4.2 The Waveform Matched Filter

4.2.1 The matched filter

4.2.2 Matched filter for the simple pulse

4.2.3 All-range matched filtering

4.2.4 Range resolution of the matched filter

4.3 Matched Filtering of Moving Targets

4.4 The Ambiguity Function

4.4.1 Definition and properties of the ambiguity function

4.4.2 Ambiguity function of the simple pulse

4.5 The Pulse Burst Waveform

4.5.1 Matched filter for the pulse burst waveform

4.5.2 Pulse-by-pulse processing

4.5.3 Range ambiguity

4.5.4 Doppler response of the pulse burst waveform

4.5.5 Ambiguity function for the pulse burst waveform

4.5.6 Relation of slow-time spectrum to ambiguity function

4.6 Frequency-Modulated Pulse Compression Waveforms

4.6.1 Linear frequency modulation

4.6.2 The principle of stationary phase

4.6.3 Ambiguity function of the LFM waveform

4.6.4 Range-Doppler coupling

4.6.5 Stretch processing

4.7 Range Side Lobe Control for FM Waveforms

4.7.1 Matched filter frequency response shaping

4.7.2 Waveform spectrum shaping

4.8 The Stepped Frequency Waveform

4.9 Phase-Modulated Pulse Compression Waveforms

4.9.1 Biphase codes

4.9.2 Polyphase codes

4.10 Costas Frequency Codes

References

Chapter 5. Doppler Processing

5.1 Alternate Forms of the Doppler Spectrum

5.2 Moving Target Indication (MTI)

5.2.1 Pulse cancellers

5.2.2 Vector formulation of the matched filter

5.2.3 Matched filters for clutter suppression

5.2.4 Blind speeds and staggered PRFs

5.2.5 MTI figures of merit

5.2.6 Limitations to MTI performance

5.3 Pulse Doppler Processing

5.3.1 The discrete time Fourier transform of a moving target

5.3.2 Sampling the DTFT: the discrete Fourier transform

5.3.3 Matched filter and filterbank interpretations of pulse Doppler processing with the DFT

5.3.4 Fine Doppler estimation

5.3.5 Modern spectral estimation in pulse Doppler processing

5.3.6 Dwell-to-dwell stagger

5.4 Pulse Pair Processing

5.5 Additional Doppler Processing Issues

5.5.1 Combined MTI and pulse Doppler processing

5.5.2 Transient effects

5.5.3 PRF Regimes and Ambiguity Resolution

5.6 Clutter Mapping and the Moving Target Detector

5.6.1 Clutter mapping

5.6.2 The moving target detector

5.7 MTI for Moving Plateforms: Adaptive Displaced Phase Center Antenna Processing

5.7.1 The DPCA concept

5.7.2 Adaptive DPCA

References

Chapter 6. Detection Fundamentals

6.1 Radar Detection as Hypothesis Testing

6.1.1 The Neyman-Pearson detection rule

6.1.2 The likelihood ratio test

6.2 Threshold Detection in Coherent Systems

6.2.1 The Gaussian case for coherent receivers

6.2.2 Unknown parameters and threshold detection

6.2.3 Linear and square-law detectors

6.2.4 Other unknown parameters

6.3 Threshold Detection of Radar Signals

6.3.1 Coherent, noncoherent, and binary integration

6.3.2 Nonfluctuating targets

6.3.3 Albersheim’s equation

6.3.4 Fluctuating targets

6.3.5 Shnidman’s equation

6.4 Binary integration

6.5 Useful Numerical Approximations

6.5.1 Approximations to the error function

6.5.2 Approximations to the magnitude function

References

Chapter 7. Constant False Alarm Rate (CFAR) Detection

7.1 The Effect of Unknown Interference Power on False Alarm Probability

7.2 Cell-Averaging CFAR

7.2.1 The effect of varying P[sub(FA)]

7.2.2 The cell-averaging CFAR concept

7.2.3 CFAR reference windows

7.3 Analysis of Cell-Averaging CFAR

7.3.1 Derivation of CA CFAR threshold

7.3.2 Cell-averaging CFAR performance

7.3.3 CFAR loss

7.4 CA CFAR Limitations

7.4.1 Target masking

7.4.2 Clutter edges

7.5 Extensions to Cell-Averaging CFAR

7.6 Order Statistic CFAR

7.7 Additional CFAR Topics

7.7.1 Adaptive CFAR

7.7.2 Two-parameter CFAR

7.7.3 Clutter map CFAR

7.7.4 Distribution-free CFAR

7.7.5 System-level control of false alarms

References

Chapter 8. Introduction to Synthetic Aperture Imaging

8.1 Introduction to SAR Fundamentals

8.1.1 Cross-range resolution in radar

8.1.2 The synthetic aperture viewpoint

8.1.3 Doppler viewpoint

8.1.4 SAR coverage and sampling

8.2 Stripmap SAR Data Characteristics

8.2.1 Stripmap SAR Geometry

8.2.2 Stripmap SAR data set

8.3 Stripmap SAR Image Formation Algorithms

8.3.1 Doppler beam sharpening

8.3.2 Quadratic phase error effects

8.3.3 Range-Doppler algorithms

8.3.4 Depth of focus

8.4 Spotlight SAR Data Characteristics

8.5 The Polar Format Image Formation Algorithm for Spotlight SAR

8.6 Interferometric SAR

8.6.1 The effect of height on a SAR image

8.6.2 IFSAR processing steps

8.7 Other Considerations

8.7.1 Motion compensation and autofocus

8.7.2 Autofocus

8.7.3 Speckle reduction

References

Chapter 9. Introduction to Beamforming and Space-Time Adaptive Processing

9.1 Spatial Filtering

9.1.1 Conventional beamforming

9.1.2 Adaptive beamforming

9.1.3 Adaptive beamforming with preprocessing

9.2 Space-Time Signal Environment

9.3 Space-Time Signal Modeling

9.4 Processing the Space-Time Signal

9.4.1 Optimum matched filtering

9.4.2 STAP metrics

9.4.3 Relation to displaced phase center antenna processing

9.4.4 Adaptive matched filtering

9.5 Computational Issues in STAP

9.5.1 Power domain solution

9.5.2 Computational load of the power domain solution

9.5.3 Voltage domain solution and computational load

9.5.4 Conversion to computational rates

9.6 Reduced-Dimension STAP

9.7 Advanced STAP Algorithms and Analysis

9.8 Limitations to STAP

References

Index