Updating Digital Geographic Database Using Vehicle-borne Laser Scanners and Line Cameras

VLMS is a mobile mapping system, where three single-row laser range scanners, six line CCD cameras as well as a GPS/INS based navigation unit are mounted on a van, measuring object geometry as well as texture along the street. This paper contributes to a method of fusing the data output of VLMS with existing geographic data sources, where focus is cast on the rectification of GPS/INS parameters, which might be quite erroneous in urban area. An algorithm is developed to correct four parameters of each GPS/INS update, i.e. xyz coordinates of vehicle position and yaw angle of vehicle orientation, by registering the laser points of VLMS with an existing data source, e.g. DSM. The algorithm is examined using the VLMS data that are taken in GINZA area, Tokyo. Manually assigning 18 sets of tie-points, GPS/INS parameters are corrected automatically and efficiently, so that the laser points of VLMS are matched to a DSM. In data fusion, a set of objects are extracted from the rectified VLMS data using an interface that was developed in our previous research, which contains of commercial sign board, traffic sign/signal, road boundary, road lights and so on. They are integrated with a 1:2500 3D map that consists of building frames only. In addition, line images of VLMS are projected onto the building facades of the 3D map, and textures are generated in an automated way.