Practical Esm Analysis

Description

Written by a prominent expert in the field, this authoritative resource considers radar parameters and how they affect ESM systems. It describes the ESM environment, including types of radar, pulse density, the latest radar developments and how they will be seen by ESM systems. Different types of ESM systems are described, with methods of calculation of Direction of Arrival (DOA) of pulses. Conventional wisdom about RF scan strategies for narrow-band receivers will be challenged and new methods (proven to be effective in trials) will be proposed. The book describes ESM Antenna separation, which plays a significant part in the generation of DOA errors, with examples of the effects for different situations. Practical ESM Analysis Contents Preface Chapter 1 Introduction to Electronic Support Measures Systems 1.1 ESM Systems: Painting a Picture of the RF Environment 1.2 ESM as an ELINT System 1.3 ESM as a Radar Warning Receiver 1.4 ESM Operators and Platforms 1.5 Topics Unique to This Book 1.5.1 Radar Beamshape Calculation 1.5.2 RF Scan Strategy Generation 1.5.3 Multipath Considerations 1.5.4 Multitracking Mitigation 1.5.5 Radar Identification Improvements Reference Chapter 2 Radar Parameters and How They Affect ESM Systems 2.1 Pulsed and Continuous-Wave (CW) Radars [1] 2.2 Pulse Descriptor Words (PDW) 2.3 RF 2.3.1 RF Agility 2.4 PRI 2.4.1 Fixed PRI 2.4.2 Staggered PRI 2.4.3 Jittered PRI 2.4.4 Switch and Dwell PRI 2.4.5 Pulse Group Repetition Interval (PGRI) 2.5 PW 2.5.1 Pulse Rise Times 2.6 Pulse Modulation 2.7 Radar Beamshapes 2.8 Scan Patterns 2.8.1 Circular Scan 2.8.2 Sector Scan 2.8.3 Raster Scan 2.8.4 Spiral Scan 2.8.5 Helical Scan 2.8.6 Conical Scan 2.8.7 Palmer Scan 2.8.8 Nodding Scan 2.8.9 Lobe Switching 2.8.10 Track-While-Scan 2.8.11 Fixed (Locked On) 2.8.12 Multiple Elevation Beam 2.8.13 AESA Radar Scan 2.9 Effective Radiated Power (ERP) 2.10 Polarization References Chapter 3 The RF Environment 3.1 The Radar Range Equation and ESM systems 3.2 Radar Horizon 3.3 Types of Radar and Their Functions 3.3.1 ATC Radars 3.3.2 HS Radars 3.3.3 Airborne Radars 3.3.4 Ship Navigation Radars 3.3.5 Weather Radars 3.3.6 Threat Radars 3.3.7 Cellular/Mobile Phones 3.3.8 Low Probability of Intercept (LPI) Radars 3.3.9 AESA Radars 3.4 Radar Pulse Density 3.5 Example of Low-Pulse Density Environment: South Australia 3.6 Example of High-Pulse Density Environment: Straits of Malacca 3.7 Number of Pulses Needed for ESM Detection References Chapter 4 ESM Equipment 4.1 ESM Antennas 4.1.1 Spiral Antennas 4.1.2 Sinuous Antennas 4.1.3 Horn Antennas 4.1.4 Antennas for Phase Comparison Systems 4.1.5 Spinning Antennas 4.2 ESM Receivers 4.2.1 Superheterodyne Receivers 4.2.2 Crystal Video Receivers 4.2.3 Instantaneous Frequency Measurement (IFM) Receivers 4.2.4 Channelized Receivers 4.3 Parameter Measurement, Accuracy, and Resolution 4.3.1 RF 4.3.2 Timing 4.3.3 PW 4.3.4 Amplitude 4.3.5 PRI Calculation 4.3.6 DOA Calculation 4.4 ESM Sensitivity 4.4.1 Target Acquisition (TA) 4.4.2 Target Tracking (TT) 4.4.3 Missile Guidance (MG) and Target Illumination (TI) Radars 4.4.4mBeacon Interrogators (BI) and Missile Beacon (BN) Signals 4.4.5 Missile Homing Systems (MH)/Seekers 4.5 RF Scan Strategies References Chapter 5 Amplitude Comparison ESM 5.1 DOA determination in Amplitude Comparison Systems 5.2 Typical Amplitude Comparison Antenna Configurations 5.3 Effect of the ESM Antenna Separation on DOA Determination 5.4 DOA Errors Due to ESM Antenna Separation 5.5 Effect of Radar Beamshape on the DOA Error 5.6 Effect of Elevation on the DOA Error 5.7 Solutions to ESM Antenna Separation Problem 5.7.1 Colocate the ESM Antennas 5.7.2 Use Pulses from the Peak of the Radar Beam 5.7.3 Adjust Antenna Activation Levels to Give an Indication of DOA Error References Chapter 6 Time Difference of Arrival ESM 6.1 DOA Determination in TDOA ESM Systems 6.2 TOA Measurement 6.3 ESM Antenna Separation Effect 6.4 Effect of ESM Sensitivity on DOA Errors 6.5 Effect of ESM Antenna Beamshape on DOA Calculation 6.6 Effect of ESM Antenna Configuration on DOA Calculation and Resolution 6.7 TDOA Histograms and DOA Uncertainty Chapter 7 Phase Comparison/Interferometer ESM 7.1 DOA Calculation in Phase Comparison Systems 7.2 Effect of Antenna Separation on DOA Calculation 7.3 Resolution of the DOA 7.4 The Effect of Radar Beamshape 7.5 Effect of Pulse Modulation 7.6 Effect of Pulse Shape 7.7 Effect of Radar RF 7.8 Phase Comparison Systems in Practice 7.9 Long Baseline Phase Comparison ESM Systems Chapter 8 Deinterleavers and ESM Processing 8.1 Deinterleaving Techniques 8.2 DOA/Frequency or DTOA/Frequency Cluster Algorithms 8.3 Time of Arrival Difference Histogram (TOADH) 8.4 Predictive Gates 8.5 Graph Theory Deinterleaver (GT) 8.6 Radar Clock Period Deinterleavers 8.7 Parameter Classification Algorithms 8.8 Track Formation References Chapter 9 Intercept-to-Track Correlation 9.1 The Intercept-to-Track Correlation Process 9.2 Overlapping Parameter Ranges 9.3 Overmerging of Tracks 9.4 Effect of Identity on ESM Track Formation 9.5 Identification Ambiguity 9.6 Solutions for Overmerging of Tracks References Chapter 10 Radar Identification and ESM Radar Libraries 10.1 Radar Parameters for an ESM Library 10.2 Data Records for an ESM Library 10.3 Library Matching Using Parameter Weighting 10.4 Library Matching Using Parameter Scoring 10.5 Library Matching Using Parameter Tolerances 10.6 User Interfaces for Reprogramming ESM Libraries 10.7 Methods for Optimizing Library Matching 10.7.1 Use Generic Library Entries for Some Types of Radar 10.7.2 Library Matching Using the Way That ESM Systems See Radars 10.7.3 A Layered Approach to Identification 10.7.4 Use of Measured Parameter Dispersions 10.7.5 Use Sensible Tolerances for ESM Correlation and Library Matching 10.7.6 Use A Priori Information 10.7.7 Use of Specific Emitter Identification (SEI) Data Chapter 11 Radar Location Estimation 11.1 Location Calculation 11.2 Location Error Ellipse 11.3 How to Draw an Error Ellipse 11.4 Radar Location in Practice 11.5 Issues with Radar Location 11.5.1 Magnitude of DOA Error 11.5.2 Intercept-to-Track Correlation 11.5.3 Orientation of the Error Ellipse 11.5.4 Sparse Data Sets 11.5.5 Multiple Radars of the Same Type 11.6 Multiplatform TDOA for Radar Location Estimation 11.7 FDOA Measurement of Radar Location 11.8 Amplitude in Radar Location Estimation 11.9 The Use of Extended Kalman Filters for Range-Finding References Chapter 12 ESM Performance Analysis 12.1 Data Recording and Required Data Capacity 12.1.1 ESM Pulse Data 12.1.2 ESM Intercept Data 12.1.3 ESM Track Data 12.1.4 ESM Status, BIT, and Alarm Data 12.1.5 Platform Navigation Data 12.1.6 Ground Truth 12.1.7 AIS Data 12.1.8 ESM Radar Library 12.2 ESM Performance Visualization 12.3 DOA Performance Assessment 12.4 ESM Track Analysis 12.5 Pulse Data Analysis 12.6 AOA Analysis 12.7 TDOA Histograms 12.8 Parameter Histograms 12.9 Location Accuracy 12.10 Probability of Intercept 12.11 Track Fragmentation 12.12 Accuracy of Identification/Ambiguity 12.13 Automation of ESM Analysis Chapter 13 ESM Testing and Trials 13.1 Laboratory Testing 13.2 Dedicated Test Ranges 13.3 The Need for Real-World ESM Testing 13.4 Planning for an ESM Test or Trial 13.4.1 Setting Test/Trial Objectives 13.4.2 The Choice of a Trial Area 13.4.3 Aircraft Flight Profile 13.4.4 Aircraft Altitude 13.4.5 Determination of Ground Truth 13.4.6 Preflight Data and Simulation Needed Before the Testing Takes Place 13.5 Example of an ESM Test/Trial Preparation 13.5.1 Test/Trial Objectives 13.5.2 ESM Platform Parameters 13.6 Preflight Preparations 13.6.1 Selection of Aircraft Route 13.6.2 Simulation of the RF Environment 13.7 Postflight Data Analysis 13.7.1 Visualization of the Operator’s Screen/Replay of Recorded Data 13.7.2 Calculation of Ground Truth 13.7.3 Analysis of ESM Track Data 13.7.4 Analysis of ESM Pulse Data References Chapter 14 Multitracking 14.1 Causes of Multitracking 14.2 DOA Errors Due to Antenna Separation 14.3 DOA Errors Due to Multipath Interference 14.4 PRI Calculation Errors Due to DOA Errors 14.5 PRI Errors Due to Missing Pulses 14.6 PRI Errors Due to Complex PRI Sequences 14.7 PRI Errors Due to PW Measurement Errors 14.8 PW Measurement Errors 14.9 RF Agility 14.10 Methods to Reduce Multitracking 14.10.1 Improve DOA Measurement 14.10.2 Ignore Intercepts with Poor DOA 14.10.3 Design the PRI Calculation Algorithm to Allow for Missing Pulses 14.10.4 Define a PRI Quality Measure 14.10.5 Use a Realistic Number of Pulses for a Complex PRI Intercept 14.10.6 Do Not Use PW as a Deinterleaving Parameter 14.10.7 Time Out Single Intercept Tracks and Do Not Display on the Operator’s Screen Chapter 15 Reflections and Multipath 15.1 Types of Reflections Affecting ESM Systems 15.2 Multipath 15.3 Multipath in Amplitude Comparison Systems 15.4 Multipath in TDOA Systems 15.5 Multipath in Phase Comparison Systems 15.6 Evidence for Multipath References Chapter 16 Factors Affecting Multipath 16.1 ESM Antenna Configuration 16.2 Radar Beamwidth 16.3 Reflection Geometry 16.4 Range to the Radar 16.5 Reflection Coefficient Reference Chapter 17 Extent of the Multipath Problem and Possible Solutions 17.1 Platform-Based Reflections 17.2 Ground-Based Reflections 17.3 Common DOA Profiles for Scanning Radars 17.4 Possible Solutions to the Multipath Problem for All Types of ESM 17.4.1 Colocate the ESM Antennas 17.4.2 Select the Pulses for Use in Track Creation 17.4.3 Use of Several Scan Peaks 17.4.4 Reduce the Pulse Amplitude Measurement Time 17.4.5 Classify the DOA Scan Type 17.4.6 Use Intrapulse Amplitude Profiles 17.5 Solutions for Multipath in Amplitude Comparison Systems 17.6 Solutions for Multipath in TDOASystems 17.7 Solution for Multipath in Phase Comparison Systems 17.8 Conclusions on Multipath References Chapter 18 The Future for ESM Systems 18.1 The Future of the RF Environment 18.1.1 AESA Radars 18.1.2 Multiple Input Multiple Output (MIMO) Radar 18.1.3 Monopulse Radars 18.1.4 Broadband Radar 18.2 ESM Processing Considerations 18.2.1 DOA Measurement 18.2.2 Deinterleavers 18.3 The Future of ESM Library Matching 18.4 Multiplatform ESM 18.5 Autonomous/Intelligent EW Systems References Appendix A Radar Beam Pattern Creation Reference Appendix B Reflection Coefficients Reference Acronyms and Abbreviations About the Author Index