Research on Method and Application of Speckle Noise Reduction of SAR Image
Daizhi Liu · Acta Geodaetica et Cartographica Sinica · 2006
Synthetic Aperture Radar(SAR) can acquire high-resolution electromagnetism information image of scene target under all weather and all time,and it has been an important remote sensing approach in Earth observation system.But the theory of SAR imaging is coherent principle,so it is inevitable to bring coherent speckle noise that strongly impacts the judgment and application of SAR image.In recently 20 years,a lot of methods smoothing speckle noise have been developed.This paper analyses these algorithms in detail and obtains some results that multi-look imaging processing can smooth speckle noise effectively,but it reduces space resolution;filter algorithms Based on space domain can smooth speckle noise efficiently,but they blur edge and detail information;wavelet multi-scale filter based on transform domain may preferably preserve edge information,but the smoothing effect is not ideal.Therefore,this paper proposed using wavelet analysis technique to fuse two or more single filter method for restraining speckle noise.The method can preserve edge,detail and texture information well when it restrains speckle noise.Finally,it was discussed simply that filter methods should be chosen in terms of different conditions and requirement in practical application.