Accuracy of light detection and ranging derived terrain data for highway location

Surface terrain information is required to economically site new or relocate existing infrastructure facilities and make final design plans. Currently, ground surveying and photogrammetric mapping are the methods used by Departments of Transportation (DOTs) to acquire these data. Both the methods are time and resource intensive as they require significant delta collection and reduction to provide the level of detail necessary for facility location. Additionally, conventional surveying entails data collection entirely in the field and may require personnel to be located on or near heavily traveled roadways. The research presented compares surface elevation data from Light Detection and Ranging (LIDAR) to that obtained from traditional photogrammetry and Global Positioning System (GPS) data collection for use in highway location and design. A pilot area previously mapped by the Iowa Department of Transportation was selected for evaluation. A comparison of the elevational accuracy and data quality of LIDAR with respect to two comparable collection methods is presented.