Sensors for Ranging and Imaging (Electromagnetic Waves)

Description

Sensors for Ranging and Imaging is a comprehensive textbook and professional reference that provides a solid background in active sensing technology. This new edition has been comprehensively updated and expanded to include the latest radar technologies. Beginning with an introductory section on signal generation, filtering and modulation, the book follows with chapters on radiometry (infrared and microwave) as a background to the active sensing process. The core of the book is concerned with active sensing, starting with active ranging and active imaging sensors (operational principles, components), and goes through the derivation of the radar (and lidar) range equations, and the detection of echo signals, both fundamental to the understanding of radar, sonar and lidar imaging. Further chapters cover signal propagation of both electromagnetic and acoustic energy, and target and clutter characteristics. The remainder of the book involves the basics of the range measurement process, active imaging with an emphasis on noise and linear frequency modulation techniques, Doppler processing, and target tracking. This systematic and thorough guide to ranging and imaging sensors is invaluable for graduate students studying sensing systems and industry professionals wishing to expand or update their knowledge. It offers clear, detailed explanations alongside worked examples to provide readers with an in-depth understanding of the material. Contents About the author Acknowledgements 1. Introduction to sensing 1.1 Introduction 1.2 A brief history of sensing 1.3 Passive infrared sensing 1.4 Sensor systems 1.5 Frequency band allocations for the electromagnetic spectrum 1.6 Frequency band allocations for the acoustic spectrum References 2. Signal processing and modulation 2.1 The nature of electronic signals 2.2 Noise 2.3 Generating analogue signals 2.4 Signals and noise in the frequency domain 2.5 Analogue signal processing 2.6 Analogue filters 2.7 Digital signal processing 2.8 Analogue modulation and demodulation 2.9 Frequency modulation 2.10 Linear frequency modulation 2.11 Pulse-coded modulation techniques 2.12 Convolution References 3. IR radiometers and image intensifiers 3.1 Introduction 3.2 Thermal emission 3.3 Emissivity and reflectivity 3.4 Detecting thermal radiation 3.5 Performance criteria for detectors 3.6 Noise processes and effects 3.7 Applications 3.8 Introduction to thermal imaging systems 3.9 Performance measures for infrared imagers 3.10 Target detection and recognition 3.11 Thermal imaging applications 3.12 Image intensifiers References 4. Millimetre-wave radiometers 4.1 Antenna power temperature correspondence 4.2 Brightness temperature 4.3 Apparent temperature 4.4 Atmospheric effects 4.5 Terrain brightness 4.6 Worked example: space-based radiometer 4.7 Antenna considerations 4.8 Receiver considerations 4.9 The system noise temperature 4.10 Radiometer temperature sensitivity 4.11 Radiometer implementation 4.12 Intermediate frequency and video gain requirements 4.13 Worked example: anti-tank sub-munition sensor design 4.14 Radiometric imaging 4.15 Applications References 5. Active ranging sensors 5.1 Overview 5.2 Triangulation 5.3 Pulsed time-of-flight operation 5.4 Using pulsed time of flight 5.5 Other methods of measuring range 5.6 The radar range equation 5.7 The acoustic range equation 5.8 TOF measurement considerations 5.9 Range measurement radar for a cruise missile References 6. Active imaging sensors 6.1 Imaging techniques 6.2 Range-gate limited 2D image construction 6.3 Beamwidth-limited 3D image construction 6.4 The lidar range equation 6.5 Lidar system performance 6.6 Digital terrain models 6.7 Airborne lidar hydrography 6.8 3D imaging 6.9 Acoustic imaging 6.10 Worked example: lidar locust tracker References 7. Signal propagation 7.1 The sensing environment 7.2 Attenuation of electromagnetic waves 7.3 Refraction of electromagnetic waves 7.4 Acoustics and vibration 7.5 Attenuation of sound in water 7.6 Reflection and refraction of sound 7.7 Multipath effects References 8. Target and clutter characteristics 8.1 Introduction 8.2 Definition of target cross-section 8.3 Radar cross-sections of man made objects 8.4 Effect of target material on RCS 8.5 RCS of living creatures 8.6 Fluctuations in radar cross-section 8.7 Radar stealth 8.8 Target cross-section in the infrared 8.9 Acoustic target cross-section 8.10 Clutter cross-section 8.11 Surface clutter backscatter 8.12 Calculating volume backscatter 8.13 Underwater Clutter 8.14 Worked example: orepass radar development References 9. Detection of signals in noise 9.1 Introduction 9.2 Radar noise 9.3 Infrared detection and lidar noise 9.4 Sonar noise 9.5 Effects of signal-to-noise ratio 9.6 The matched filter 9.7 Coherent detection 9.8 Integration of pulse trains 9.9 Detection of fluctuating signals 9.10 Detecting targets in clutter 9.11 Constant false alarm rate (CFAR) processors 9.12 Target detection analysis 9.13 Noise jamming References 10. Doppler measurement 10.1 The Doppler shift 10.2 Doppler geometry 10.3 Doppler shift extraction 10.4 Pulsed Doppler 10.5 Doppler sensors 10.6 Doppler target generators 10.7 Case study: estimating the speed of radio-controlled aircraft References 11. High-range-resolution techniques 11.1 Classical modulation techniques 11.2 Amplitude modulation 11.3 Frequency and phase modulation 11.4 Phase-coded pulse compression 11.5 SAW-based pulse compression 11.6 Step frequency 11.7 Frequency-modulated continuous-wave radar 11.8 Stretch 11.9 Interrupted FMCW 11.10 Side lobes and weighting for linear FM systems 11.11 Transmitter leakage and phase noise in FMCW radars 11.12 High-resolution radar systems 11.13 Worked example: Brimstone antitank missile References 12. High angular-resolution techniques 12.1 Introduction 12.2 Phased arrays 12.3 The radiation pattern 12.4 Beam steering 12.5 Array characteristics 12.6 Applications 12.7 Side-scan sonar 12.8 Worked example: performance of the ICT-5202 transducer 12.9 Doppler beam-sharpening 12.10 Operational principles of synthetic aperture 12.11 Range and cross-range resolution 12.12 Worked example: synthetic-aperture sonar 12.13 Radar-image-quality issues 12.14 SAR on unmanned aerial vehicles 12.15 Airborne SAR capability 12.16 Space-based SAR 12.17 Magellan Mission to Venus References 13. Range and angle estimation and tracking 13.1 Introduction 13.2 Range estimation and tracking 13.3 Principles of a split-gate tracker 13.4 Range tracking loop implementation 13.5 Ultrasonic range tracker example 13.6 Tracking noise after filtering 13.7 Tracking lag for an accelerating target 13.8 Worked example: range tracker bandwidth optimisation 13.9 Range tracking systems 13.10 Seduction jamming 13.11 Angle measurement 13.12 Angle tracking principles 13.13 Lobe switching (sequential lobing) 13.14 Conical scan 13.15 Infrared target trackers 13.16 Amplitude comparison monopulse 13.17 Comparison between conscan and monopulse 13.18 Angle tracking loops 13.19 Angle estimation and tracking applications 13.20 Worked example: combined acoustic and infrared tracker 13.21 Angle track jamming 13.22 Triangulation and trilateration References 14. Tracking moving targets 14.1 Track while scan 14.2 The coherent pulsed tracking radar 14.3 Limitations to MTI performance 14.4 Range-gated pulsed Doppler tracking 14.5 Coordinate frames 14.6 Antenna mounts and servo systems 14.7 On-axis tracking 14.8 Millimetre-wave tracking radar 14.9 Tracking in Cartesian space 14.10 Combining radar and optronic tracking 14.11 Worked example: fire control radar References 15. RFID tags and transponders 15.1 Principle of operation 15.2 History 15.3 Secondary surveillance radar 15.4 Automatic Dependent Surveillance–Broadcast 15.5 AIS transponders 15.6 Radio-frequency identification (RFID) systems 15.7 Other applications 15.8 Social issues of RFID 15.9 Technical challenges 15.10 Harmonic radar 15.11 Passive reflected power modulation 15.12 Battlefield combat ID system 15.13 Indoor localisation References 16. Tomography and 3D imaging 16.1 Principle of operation 16.2 CT imaging 16.3 Magnetic resonance imaging 16.4 Magnetic resonance images 16.5 Functional MRI investigations of brain function 16.6 Positron emission tomography 16.7 3D ultrasound imaging 16.8 3D extension 16.9 Pocket ultrasound 16.10 Other ultrasound imaging modalities 16.11 Sonar imaging in 3D 16.12 Ground-penetrating radar 16.13 Worked example: detecting a ruby nodule in a rock matrix References Index