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1. INTRODUCT TON 
There are two ways to process SAR data. One is an optical processing and 
the other is a digital processing. From now on, a digital processing will be 
used mainly because it can produce more precise images and it can be easily 
adapted to various parameters of spaceborne and airborne SAR. 
In order to process SAR data digitally, a minicomputer with an array- 
processor (e.g. AP120B ) is used in some laboratories. Though this combination 
provides a high cost-performance system, the processing speed is low. For 
example, it takes 2 to 3 hours to process a full scene using a minicomputer with 
three array-processors. The Japanese ERS-1 project is planned to take 50-80 
scenes per day. In order to process these data within a day, a scene must be 
processed within 10 minutes. 
The authors have conducted a study on data processing using a super- 
computer DIE In this paper, hardware and software features are 
described. In section 2, FACOM VP-200/VP-100 is introduced. In section 3, the 
algorithms which shorten the throughput time are described. In section 4, a 
example of SEASAT SAR image which was reconstructed using FACOM VP-200 is 
introduced.