EXTRACTION OF URBAN FOOTPRINT OF BENGALURU CITY USING MICROWAVE REMOTE SENSING

Abstract

Monitoring the urban development/change is of critical importance in planning the future infrastructure of a city. The use of satellite images in urban related studies has yielded in exemplary results. The city of Bengaluru, with high variation in urban landscape is most suited for this study. In this paper, the potential of the SAR imagery in understanding and characterizing the urban features is studied. The SAR images have unique characteristics such as double bounce and corner reflectors which are prominent in an urban landscape. The diverse urban features are characterised by comparing the graphs derived from the image statistics of temporal Sentinel-1 dual polarized data. For the generation of the urban footprint a rule based approach and an object oriented approach has been implemented in this study. The stack of coherence image and synthetic bands derived from image statistics of the VV polarization is used as the input image for the same. The final urban footprint is derived by the comparison of the output from both the methods. The results are authenticated with the urban footprint obtained by optical imagery of the same area for better understanding and improvement of the algorithm. The observations are made regarding the contribution of SAR in the study of urban features and the feasibility of implementation in the mainstream analysis.