Improved multiple look technique

Synthetic aperture radar (SAR) images are contaminated by speckle noise. To suppress speckle, N lower resolution images (looks) are generated and averaged. This improves the signal-to-speckle noise ratio (SSNR) by a factor of /spl radic/N, assuming that the corresponding pixels in these looks have equal mean intensities. In practice this assumption is not always valid and as such SSNR is degraded. A new adaptive technique that replaces the conventionally averaged resultant pixel with one of the N available pixels is found to produce better SSNR under these circumstances.