A Development of Change Detection System for Urban Monitoring

This paper presents the application system of remote sensing which monitors urban objects. The system mainly aims to help public officials detect the changed areas using easy method and friendly user interface. The land cover images and the ortho-rectified aerial images which have been linked together by using geo-coordinates information are the main data to be imported and processed in the system. The modules in the system have consisted of land cover change detection and urban change detection. The latter one is for urban monitoring and planning, vector data update. Especially, urban change detection module is very useful to reduce workload of public officials performing aerial image interpretation. To be more specific, an image differencing technique and change vector technique in conjunction with transparency viewing function are employed to detect the candidates of changed area and object. Change vector technique is based on the concept of spectral angle difference of pixels in image space between co-registered images from two dates. A final product is an image layer indicating location where change occurred by overlaying of digital thematic map. We mainly present the procedure regarding change detection run by Link Viewer module.