A continuative variable resolution digital elevation model for ground-based photogrammetry

A new digital elevation model (DEM) is presented for accurate surface representation in photogrammetric processing of stereo ground-based imagery. This model is named the continuative variable resolution DEM (cvrDEM). In contrast to traditional grid-based DEMs that have only one fixed resolution, this new model can provide resolutions that vary depending on the range represented in the ground-based imagery. Functions for deriving radial and angular resolutions from the cvrDEM have been derived, and a corresponding storage structure for the polar coordinates has been developed. Experimental results using publically available NASA Mars Exploration Rover 2003 imagery demonstrate the effectiveness of the cvrDEM model: It can significantly reduce storage space while fully maintaining the most useful level of mapping accuracy relevant to the range from the imaging station. A terrestrial laser scanning data set was also used to validate the effectiveness of the cvrDEM.