Research On SAR Image Compression Technology Based On Optronic Processing

Synthetic Aperture Radar(SAR)is an active microwave imaging radar which is widely used in aerospace science and remote sensing field.SAR can be mounted on aircraft,satellite and other aircraft,it is used for high resolution and wide swath earth observation all day and all-weather.With the development and wide application of SAR radar,how to effectively process high-capacity and high-resolution SAR images has become an inevitable but important issue.Saving transmission power,reducing transmission delay,and reducing storage pressure are of great value for SAR image compression.Traditional SAR image compression technologies are mostly based on lossy compression technology by digital processing.For SAR images,which tend to have high resolution,high data capacity and low latency processing,put forward higher requirements for the storage and computing power by digital processing.The large storage and computing pressures cannot fully meet the trend of future.This dissertation uses the method of optronic and digital processing to compress the SAR image.The reason to use optronic processing is that optronic processing is fast,efficient and high-capacity.In addition,the device is simple,which can be convenient that the computer cannot be.Based on the above discussion,we have designed two sets of optical SAR image compression systems,and verified the optronic processing that can be used in SAR image compression.Different from the traditional optical system for processing ordinary optical images,the two systems designed in this paper are characterized by complex speckle noise and low pixel correlation of SAR images.The optical cosine transform and optical wavelet transform,realized by the Fourier transform property of convex lenses,which were to complete the complex arithmetic operations in SAR image compression and using scientific camera to capture recording results.Previous image preprocessing and coding steps still require digital processing.The experiments tried in this dissertation are based on optical system,which can eliminate the complicated and cumbersome calculation,slow down the storage pressure and shorten the calculation delay in the SAR image compression processing.The experimental setup of the optronic SAR image compression is designed,it is used to validate the two previous optronic compression methods.Finally,this dissertation analyzes the problems encountered in the experimentation,and proposes the work that needs to be improved in the next step.