7.3.5 Filtering

As mentioned, RADARSAT data acquired in Fine mode is more prone to speckle than Standard mode data. To demonstrate the usefulness of applying a filter in order to increase stereo-viewability, an area of approximately 10x10 km of the Okanagan, B.C. data was prepared with and without a filter. The unfiltered version contains a large amount of speckle, which interferes with stereo viewing. An adaptive filter (Lopez et al., 1985) was then used to reduce the amount of speckle. This resulted in a cleaner image, which is easier to view in stereo. However, there is a loss of some detail. Roads and boundaries between water bodies and land are not as clearly delineated in the filtered image as in the unfiltered image. Some elevation information is also lost.