Conversion of GIS contour maps into surface digital elevation models for robotic surveying

With the advent of new technologies, robotic surveying systems are being developed to facilitate the collection of ground-based information to validate and complement data collected by traditional and satellite-based instruments. The development of such systems necessitates an accurate set of reference data. Given the limitations of current in situ measurement methods to aid remote sensing, this paper outlines a method for the creation of three-dimensional data from the most common public data source, 2D contour maps. Using image processing and interpolation techniques, this method was first tested against data collected by a robotic survey system and against methods that a human expert would use. Comparatively, our method yielded vertical RMSE in the range of (0.006066 - 0.39) [m] for different horizontal spatial resolutions. Twenty additional sample contour maps were identified to further vet our method against that of a human expert as a function of the 3D interpolation method selected. These tests provided errors in the centimeter range and also revealed that the linear triangular mesh interpolator is the best choice for this type of image input data.