A STUDY OF MAPPING BY COMPUTER WITH DIGITAL SATELLITE DATA

We conducted this study to test the feasibility of the technique by using the Earth Resources Technology Satellite (LANDSAT) multispectral scanner (MSS) data to draw a forest map. The study area is located in Kunming region, Yunnan Province, China。 We made use of the data of LANDSAT computer compatible tapes(CCT) from LANDSAT-2 overpass on Jan. 20, 1974. Image processing was Sophisticated with an international imaging system (I², S 10l). In image processing, the first step included image enhancement within a window by the methods of ration and Karhunen-Loeve transformation, unsupervised and supervised classification. Ration enhancement was more successful On the basis of this, the second step was image geometric correction and ration processing over the study region. The computer-generated map was processed from the ration MSS4/MSS5, MSS5/MSS6 and MSS6/MSS7. Output was provided as hard copy by an Optronics C-4500 Colomation. The accuracy of mapping was verified by a comparision with available forest map from ground survey. Results of the accuracy evaluation are forest land 87.0%, non-forest land 81.0%, farm land 36.4%, water area 99.6%, urban districts and building area 98.7%, and the average accuracy was 80.5%. The preliminary results from automatic mapping were satisfactory. Further research in the aspect is desirable.