Improvement of a low cost mobile mapping system with a triangular arrangement of photographic cameras

Abstract

The matter is the traffic way (street, road or railroad), its mapping the general objective and, in particular, the mapping of a critic segment. Three are the specific objectives: the first is tactical and it aims to improve a low cost mobile mapping system built four years ago in the lab; the second searches the integration of the existing system to the road mapping process through its mounting on a regular vehicle with the addition of a third camera; the last treats the mapping of critic road segment (high incidence of accidents). The mounting of a low cost system makes the method affordable for road mapping. The components are satellite positioning and inertial sensors and photographic cameras to produce a spatial position of any detail in or surrounding a road. Two issues justify this project: cost and image orientation; this is a classical problem in mapping and it tends to automation. The third camera makes a triangle of cameras with the optical axes parallel and pointed forward. The adapted bundle block phototriangulation has been called "photogrammetric traverse" and it has two roles: to supply an eventual lack of the satellite signal (mostly in urban areas) and the estimation of exterior orientation parameters. The camera triangular basis will provide a stable geometry so that the "photogrammetric traverse" will release better estimates of the camera orientation parameters. The reason is that the redundancy of the observations is higher and three non coplanar photogrammetric rays carry a better quality intersection. Both improve the control of error propagation. (AU)