A New Index for Steel Framed Roof Information Extraction Based on Remote Sensing
There are a great number of index methods used to extract impervious surface from satellite images. However, these indices are not robust enough to detect steel framed roof due to the diversity of impervious materials. The extraction of steel framed roof information by remote sensing technology is becoming increasingly important because of its environmental and socio-economic significance. A new index, Normalized Difference Steel framed roof Index (NDSI) is proposed to extract steel framed roof surface information from TM images. The NDSI was created based on its spectral characteristics of TM image and the steel framed roof information can be extracted fast by NDSI threshold method. Additionally, Shijiazhuang city, which has experienced rapid urbanization, was chosen as the study area. And the classification results show that the new index NDSI can effectively extract steel framed roof information with higher accuracy.