Mobile mapping system and computing methods for modelling of road environment

Mobile mapping is a new way of efficiently collecting three-dimensional data from the road environment. Mobile mapping systems are cost efficient and robust technique to acquire information about even highly dynamic environments like highways and urban streets, where the data collection has previously been laborious and even dangerous for the staff performing the surveying. The dynamic mobile mapping systems could access the site with less risk to the personnel and with less need for road closures. The need for high resolution and details captured in to the data for street and road inventories, or city modelling, are the main reasons for the rapid adoption of the mobile mapping techniques in these fields. Lidar based mobile mapping system produces three-dimensional points from the surrounding objects. Typically, two-dimensional profiling scanner is mounted on the system and the third dimension is achieved by the movement of the vehicle. The characteristics of the obtained point cloud depend largely on the sensor arrangement and the sensor properties. The ROAMER, a single-scanner system for road environment mapping presented in this paper, is able to use various tilted scanning planes for the point acquisition with 120 kHz point measurement frequency and up to 48 Hz profile measurement rate. The relative point precision for the system is estimated to be a few millimetres, but is eventually defined absolutely by the accuracy of the navigation solution that could be provided in real-time, or more reliably through post-processing. We believe that in the future, lidar based mobile mapping will be used considerably for urban and road environment modelling, as well as in many other applications in the fields of construction, forestry, railways, and even in environmental modelling and monitoring e.g. hydrology and glaciology. In urban context, the main applications of these models could include urban and environmental planning, road safety assessment, road construction planning and navigation.