Digital pre-processing techniques of landsat data in high relief area—an Himalayan example

Summary and Conclusion

The analysis of the Landsat data for a Himalayan Test area recorded with a low sun elevation has shown that most of the information is due to illumination and shadow effects, which can be satisfactorily separated from the effects of the ground-cover on the radiance levels, by using the PC analysis and the Euclidean Distance and Directional Cosine techniques. At the same time effective data compression is achieved without loss of information. For a visual interpretation, both the images of “relief” and “groundcover” are necessary. Proper location, using drainage divides and channel network may be done on the “relief” image. Vegetation boundaries appear on the other image. Comparison of groundcover images of September 1972 and May 1974 indicates the utility of these these techniques for sequential studies, particularly the separation of deciduous and non-deciduous vegetation in a broad manner.