Revising car navigation database using VLMS (vehicle-borne laser mapping system)

Map database for car navigation systems accommodates a variety of urban information such as gas stations and convenience stores to satisfy the growing users need. Though map databases are revised once or twice a year, it may not be very satisfactory, not only for car navigation services but also for future passenger navigation services, because many new shops are constantly emerging while many others are disappearing due to severe competition. Nevertheless, actual map manufacturing work still depends on labor-intensive methods. VLMS is developed to acquire a three dimensional data in urban area reliably, quickly and at high resolution for 3D urban GIS database. It consists of three laser scanners, six line cameras, INS and GPS. The platform vehicle can be operated at a speed of 40 km/hr. In addition, the high-resolution imagery and spatial data can be applied to acquire sign-board information of urban facilities, for example, convenience stores, gas stations, etc. It is possible to automatically identify them with image-processing methods. This paper describes the methodology and results of applying VLMS imagery for automated revision of signboard information.