1. 강원대학교 지구물리학과 이 훈 열 hoonyol@kangwon.ac.kr
교육용 인공위성 영상레이더 자료처리 공개 프로그램 (eSAR Processor)의 개발 Development of an educational Synthetic Aperture Radar Processor
강원대학교 지구물리학과
이 훈 열

2. One Page Introduction to SAR
Active Imaging Radar
Microwave
Weather-free and Day & night imaging
High Gain Antenna
Synthesized large aperture through signal processing -> dramatically enhanced (azimuth) resolution
2D image + Phase = 3D measurement
InSAR, DInSAR, PolSAR, Pol-InSAR, PSInSAR
Detection, classification, mm-scale surface motion, etc.

3. SAR Product Levels Product Levels Data Type Prospectus Users RAW
RAW
Geophysicist 1
Focused
Scientist 2
Geocoded
GIS specialist 3+
Fully calibrated
GIS users

4. Geophysical Approach to SAR
Geophysicists are in a good position to
understand SAR system through profound data processing from the beginning (RAW),
read engineer’s mind who designed the system,
do science,
and give feedback to RF engineers.

5. Limited or even dead ended
SAR Processors
Commercial
Educational
Price
Extremely expensive
Free
Learning
Quick
Slow
Use
Convenient
Difficult
Source Code
Hidden
Open
Versatility
Limited or even dead ended
Market
limited
Open to all

6. eSAR Processor SAR Focusing and InSAR Processor
Developed for graduate course
Range-Doppler Algorithm
Effective use of computer facilities
One PC for each student
Minimum PC specification (CPU, Memory, HDD)
Small areas
Based on cygwin (Linux emulator for Windows, Free)
GNU C-Compiler (Free)
Machine independent FFT Algorithm from Numerical Recipes
Interactive education – can see each processing step
Open and easy source code (ANSI-C)
Everything’s Free
Open Forum
No GUI currently, but some can be added
Student study the SAR system and structure of data -> versatile to any data type

7. SAR Focusing For MxN pixel image (2ax2b): Memory Usage CPU Time HDD
= MxNx2(complex)x8(double) Bytes
(ex. 64MB for 1024x4096,
256MB for 8192x2048)
CPU Time
= 2D FFT and iFFT
= 2*Ma/2*N + 2*Nb/2*M
= MN(a+b) multiplications
(ex. 88M multiplications for 1024x4096.
a few minutes in PIII CPU and
dozens of seconds in PIV CPU )
HDD
Minimum 4-look amplitude: MxN
(ex. 4M for 1024x4096)
Maximum: MxNx4(float)x2(complex)x8(outputs)
(ex. 256M for 1024x4096)

8. SAR Focusing Steps (2048x4096) range azimuth azimuth frequency RAW
Range Compressed
Range Migrated

9. SAR Focusing Results
4-look SAR amplitude (40km x 20km)

10. More to come SAR Interferometry SAR Polarimetry Some GUI
More accurate and robust SAR focusing algorithm
Open source code:
An online (or offline) forum can be organized upon the user’s request.