ISRS 2009 Haeundae Grand Hotel Busan Korea 28

ISRS 2009, Haeundae Grand Hotel, Busan, Korea, 28 -30 October, 2009 Development of Focusing Algorithms for Arc-scanning Ground-Based Synthetic Aperture Radar Hoonyol Lee Dept. of Geophysics, Kangwon National University Seong-Jun Cho and Kwang-Eun Kim Korea Institute of Geosciences and Mineral Resources

Contents Introduction to Arc. SAR Focusing Algorithms for Arc. SAR Spot and Scan Modes Comparison of Resolutions Arc. SAR Spot Mode, Arc. SAR Scan Mode, Linearscanning GBSAR, and a conventional radar (Arc. RAR) Results Conclusions

Introduction to Arc. SAR

GB-SAR(KIGAM-KNU) DIn. SAR tested: Phase stability of 1° (0. 1 mm range) was achieved for several hours for stable reflectors, rendering phase change of 10 ° to be assured (1 mm accuracy). PSIn. SAR displacement measurement: R 2=0. 9999 achieved. GB-SAR can be used for various applications such as: Safety monitoring of natural or anthropogenic structures Microwave backscattering properties of target New SAR system concept design

Arc. SAR Concept AWS

Arc. SAR RF Configuration

Arc. SAR Design

Circular Rail and Extendable Boom

Arc. SAR Truck

Arc. SAR Leveler

Arc. SAR Leveler

Arc. SAR Data Acquisition

GB-SAR vs Arc. SAR GB-SAR Arc. SAR(World first) Scan Type Linear Arc Polarization Full Scan Load Heavy Light Azimuth Resolution High 3 times Higher than GB -SAR Installation Ground-fixed Automobile: higher mobility Motion Control Simple (linear motion) Complex (2 rotational motions) SAR focusing Conventional New Major application DIn. SAR change detection Emergency Mapping DIn. SAR change detection

Arc. SAR Focusing Algorithms

Arc. SAR Geometry Polar Imaging Domain: Range and “True” azimuth

Arc. SAR Imaging Modes Spot Mode Dual rotational motion (boom and antenna) Coherent Integration Arc can be 180 degree maximum. High resolution Limited azimuth coverage Scan Mode Single rotational motion (boom only) Coherent Integration Arc is the width of the antenna beam. Low resolution Full azimuth coverage

Arc. SAR Focusing Spot Mode Deramp-FFT Algorithm in Polar Format Range Compressed Signal: Scan Mode Range-Doppler Algorithm in Polar Format Range Compressed signal: Coherent Integration Arc: Range Function:

Arc. SAR Focusing Spot Mode Taylor’s Expansion at : Scan Mode Taylor’s Expansion at Deramp Function: Azimuth Compression: IFFT : Matched Filter: Azimuth Compression: Matched Filtering

Arc. SAR Focusing Spot Mode Focused Image: Scan Mode Focused Image: Azimuth (angular) Resolution: Phase:

Flowchart Raw Data Range Hamming Filter Range Compression Azimuth FFT Range Migration Multiply Deramp function Azimuth Matched Filter Azimuth Hamming Filter Azimuth FFT Azimuth i. FFT Geometric Correction Output Deramp-FFT Range-Doppler

Azimuth Resolutions

Results

Simulation: Arc. SAR Spot Mode

Simulation: Arc. SAR Scan Mode

Arc. SAR Scan Mode Experiment

Further Research A brand-new truck has arrived and is under reform. Second motor control for Arc. SAR Spot Mode will be added. Integrated Controller SAR, In. SAR, Surface motion detector software GPS, AWS Increase Mileage!

Conclusions Image focusing algorithms for Arc. SAR were developed in polar coordinates. The Deramp-FFT algorithm was used for Arc. SAR Spot Mode and the Range-Doppler algorithm for Arc. SAR Scan Mode. Comparisons of image resolutions between various ground-based radar systems confirmed the advantages of Arc. SAR: Arc. SAR Spot Mode > Linear-scanning GBSAR > Arc. SAR Spot Mode > Arc. RAR 167. 2 53. 4 11. 0 1 The system will be mounted on a “new” truck and will provide a rapid response tool for various applications such as regional mapping and environmental hazard monitoring.