Extraction of the Ming Great Wall Information from Remote Sensing Imagery and DEM
The Great Wall has been in the severe danger of the World Culture Heritages list. it is difficult to investigate the situation, because the Great Wall stretches too long and we do not know the exact layout of the Great Wall. The protection and management of the Great Wall is a hard work. In this paper, there is a new method to extract the information of the Great Wall from the satellite images. The research area BaDaLing is one of the typical stone Great Wall. Firstly we obtain the NDVI value from a SPOT5 image after fusion and orthorectification. Then use the DEM hydrology function to extract the ridge of the watershed, and buffer it. At last we put the NDVI and the buffered data together to make an overlay, then the Great Wall information is extracted. We apply the shape index to the overlay to get rid of other spots. The result is confirmed through the field survey. The method can provide reference to the Great Wall survey.