Airborne Circularly Polarized SAR 1st Edition by Yuta Izumi, Josaphat Tetuko Sri Sumantyo, Cahya Edi Santosa, Ming Yam Chua ISBN 9781032250038 1032250038

1 Introduction of Synthetic Aperture Radar

1.1 Introduction

1.2 History of Synthetic Aperture Radar

1.3 Spaceborne Synthetic Aperture Radar

1.4 Airborne Synthetic Aperture Radar

1.5 Unmanned Aerial Vehicle Onboard Synthetic Aperture Radar

1.6 Focus Discussions in this Book

References

2 Basics of SAR Polarimetry

2.1 Polarization State Representation

2.1.1 Maxwell Equation

2.1.2 Wave Equation and Propagation

2.1.3 Polarization Ellipse

2.1.4 Jones Vector

2.1.5 Vector Transformation

2.1.6 Stokes Vector

2.1.7 Axial Ratio

2.2 EM Reflection, Transmission, and Scattering in Circular Polarization

2.3 Matrix Representation of the Scattering Process

2.3.1 Scattering Matrix in Linear Polarization Basis

2.3.2 Scattering Matrix in Circular Polarization Basis

2.3.3 Second-Order Polarimetric Matrices in Linear Polarization Basis

2.3.4 Second-Order Polarimetric Matrices in Circular Polarization Basis

2.4 Polarimetric SAR Target Decomposition Theorem

2.4.1 Introduction of Polarimetric SAR Target Decomposition

2.4.2 Target Decomposition for Fully Polarimetric Systems

2.4.3 Eigenvector-Based Decomposition for Dual Polarimetric Systems

2.5 Compact Polarimetric SAR

2.5.1 Basic Concept of Compact Polarimetry

2.5.2 Compact Polarimetry Data Analysis

2.5.3 Target Decomposition Theorem for Compact Mode

2.5.4 Eigenvector-Based Decomposition for Compact Modes

2.6 Summary

References

3 System Design

3.1 Introduction

3.2 Mission

3.3 Parameter Design

3.3.1 Objective and Specification of SAR

3.3.2 The Geometry of the Platform and SAR

3.3.3 Resolution

3.3.4 Signal-to-Noise Ratio

3.3.5 Sampling Time Interval

3.3.6 PRF and Duty Cycle

3.3.7 Bandwidth

3.3.8 Transmit Power

3.3.9 Time-Bandwidth Product

3.3.10 Doppler Bandwidth

3.3.11 Synthetic Aperture

3.3.12 Memory Estimation

3.4 Summary

References

4 RF System

4.1 Introduction

4.2 System Block Diagram

4.3 Radio Frequency Unit

4.3.1 SAR Transmitter

4.3.1.1 The Upconverter Circuit

4.3.1.2 Gating and Amplification Circuit

4.3.1.3 DC Biasing Circuit

4.3.1.4 Embedded Controller

4.3.2 SAR Receiver

4.3.2.1 Gating and Amplification Circuit

4.3.2.2 Downconverter Circuit

4.3.2.3 DC Biasing Circuit

4.3.3 Local Oscillator Unit

References

5 Baseband and Control Unit

5.1 Introduction

5.2 CHIRP GENERATOR

5.2.1 The Chirp Signal

5.2.2 Chirp Waveform Synthesis

5.2.2.1 Settling Time

5.2.2.2 Glitch Impulse Area

5.2.2.3 Signal-to-Noise Ratio (SNR)

5.2.2.4 Spurious Free Dynamic Range (SFDR)

5.3 Data Acquisition Unit (DAU)

5.4 Timing and Control Unit (TCU)

5.5 Inertial Navigation System

5.6 Power Unit

References

6 Circularly Polarized Antenna

6.1 Introduction

6.2 Basic Antenna Parameters

6.2.1 Return-Loss and Voltage Standing Wave Ratio (VSWR)

6.2.2 Radiation Pattern

6.2.3 Directivity

6.2.4 Gain and Efficiency

6.2.5 Polarization

6.3 The SAR Antenna Requirements

6.3.1 Antenna’s Aperture and Beamwidth

6.3.2 Antenna’s Gain

6.3.3 Antenna’s Bandwidth

6.4 Circularly Polarized Antenna Design

6.4.1 Hinotori C2 Airborne Circularly Polarized SAR

6.4.2 Microstrip Array Antenna

6.4.3 Unit Element of the Circularly Polarized Antenna

6.4.4 Broadening Circularly Polarized Antennas Bandwidth

6.4.5 The 2 × 2 Subarray Arrangement

6.4.5.1 Element Separation

6.4.5.2 The Serial Sequential Rotation Configuration

6.4.5.3 Impedance Matching of the Feeding Network

6.4.5.4 Subarray Evaluation

6.4.6 Large Array Expansion

6.4.6.1 The 4 × 4 Subarray

6.4.6.2 The 8 × 8 Subarray

6.4.6.3 The 16 × 8 Subarray

6.4.7 The Prototype Antenna

6.4.8 Performance of the Hinotori C2 Antenna

References

7 Ground Test, Airborne Installation, and Flight Mission

7.1 Introduction

7.2 Hinotori-C SAR Subsystems Test

7.2.1 Clock

7.2.2 RF Transmitter

7.2.2.1 Output Power Measurement

7.2.2.2 Bandwidth Measurement

7.2.3 RF Receiver

7.2.3.1 1dB Compression Point

7.2.3.2 Receiver Dynamic Range and Bandwidth

7.2.3.3 Noise Floor Measurement

7.2.4 Chirp Generator and Timing and Control Unit

7.2.5 Data Acquisition System

7.3 System Integration and Full System Test

7.3.1 Full System Loopback Test

7.3.2 Ground Test

7.3.2.1 SAR System (with Antenna) Noise Floor Measurement

7.3.2.2 Static SAR Distributed Target Test

7.3.2.3 SAR Point Target Ground Imaging Experiment

7.4 The Hinotori-C2 Flight Test

7.4.1 SAR System Installation

7.4.1.1 Pre-Flight Tests

7.4.1.2 Maiden Flight of Hinotori-C

References

8 SAR Image Formation

8.1 Introduction

8.2 Matched Filter in Pulse Compression

8.3 SAR Point Target Analysis

8.4 SAR Point Target Model

8.5 Range-Doppler Algorithm (RDA)

8.5.1 Range Compression

8.5.2 Range Cell Migration Correction

8.5.3 Azimuth Compression

8.6 The Hinotori-C SAR Processor

8.6.1 Generating Point Target Simulation Raw Data

8.6.2 Processing Point Target Simulation Raw Data Using RDA

8.6.2.1 Data Extraction

8.6.2.2 Range Compression

8.6.2.3 Range Cell Migration Correction

8.6.2.4 Azimuth Compression

8.6.3 Processing Hinotori-C2 Mission Data

8.6.3.1 Data Preparation

8.6.3.2 RDA Processing

8.6.3.3 Multilooking

References

9 Applications

9.1 Introduction

9.2 Indoor Circularly Polarized SAR Scattering Experiment

9.2.1 Imaging Geometry and System Description

9.2.2 Scattering Experiment on Canonical Targets and Its Results

9.2.3 Scattering Experiment on Aircraft Model (N219)

9.3 Application: Analysis of Polarimetric SAR Modes for Rice Phenology Monitoring

9.3.1 Experimental Scheme

9.3.2 Phenology Description of Cultivated Rice

9.3.3 Data Analysis Methodology

9.3.4 Rice Monitoring Results and Discussion

9.3.4.1 Backscattering Coefficient

9.3.4.2 H/a– Decomposition

9.3.4.3 Four- and Three-Component Decomposition

9.3.5 Conclusion in Rice Phenology Monitoring Study

9.4 Application: Airborne Circularly Polarized SAR Image Analysis

9.5 Summary

References

10 Summary

10.1 Summary

10.2 Future Research

References

Index