??? ???? ????? ???? ?? ???? (eSAR Processor)? ?? Development of an educational Synthetic Aperture Radar Processor

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??? ???? ????? ???? ?? ???? (eSAR Processor)?
??Development of an educational Synthetic
Aperture Radar Processor

• ????? ??????
• ? ? ?
• hoonyol_at_kangwon.ac.kr

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One Page Introduction to SAR

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

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SAR Product Levels
Product Levels Data Type Prospectus Users
0 RAW Geophysicist
1 Focused Scientist
2 Geocoded GIS specialist
3 Fully calibrated GIS users
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Geophysical Approach to SAR

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

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SAR Processors
Commercial Educational
Price Extremely expensive Free
Learning Quick Slow
Use Convenient Difficult
Source Code Hidden Open
Versatility Limited or even dead ended Open
Market limited Open to all
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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)
• Everythings Free
• Open Forum
• No GUI currently, but some can be added
• Student study the SAR system and structure of
  data -gt versatile to any data type

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SAR Focusing

• For MxN pixel image (2ax2b)
• Memory Usage
• MxNx2(complex)x8(double) Bytes
• (ex. 64MB for 1024x4096,
• 256MB for 8192x2048)
• CPU Time
• 2D FFT and iFFT
• 2Ma/2N 2Nb/2M
• MN(ab) 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)

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SAR Focusing Steps (2048x4096)
range
azimuth
azimuth frequency
RAW
Range Compressed
Range Migrated
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SAR Focusing Results
4-look SAR amplitude (40km x 20km)
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More to come

• SAR Interferometry
• SAR Polarimetry
• Some GUI
• More accurate and robust SAR focusing algorithm
• Open source code
• www.kangwon.ac.kr/geophy/
• An online (or offline) forum can be organized
  upon the users request.