Collaboration of Real Time Gis and Spatial Data for Large Scale Map

Much local government has been using large scale digital maps with Geographic Information System (GIS). However, the updating method of a map is not established yet. The purpose of this study is the real-time renewal of the digital map for local government by collaboration of REAR TIME GIS and spatial data. In this study, spatial data means Remote Sensing imageries and Real-time Kinematic Global Positioning System (RTK-GPS). REAL TIME GIS is the system for real-time updating at the field site by using RTK-GPS, GIS and cellular phone. First, change of the city is easily found that the Remote Sensing imageries are able to overlay with digital map by using GIS. Next, position of changed area was measured by RTK-GPS. But, RTK-GPS data did not correspond with digital maps because of different geodetic system. It is necessary to transform digital maps of an old geodetic system to new ones. In order to transform map coordinate, the parameters were calculated using Affine Transformation. In this paper, these parameters were named “High-Accuracy Regional Parameter (HARP)”. Actual experiment was performed at two places in the narrow area at Kanazawa district in Japan. It was verified how far there are differences between BaseMap (BM) and RTK-GPS measuring data. As a result, the difference was 5~10cm at longitude and 30 cm at latitude. The differences at longitude are allowed in large scale digital map. It is suggested that the process of REAL TIME GIS and HARP should be introduced to the work of local government.