| 摘要 |
A method of deriving a digital terrain model from a digital surface model of an area of interest comprises: dividing the area of interest into a plurality of area portions or patches (205); calculating, from the digital surface model, a set of candidate surfaces adapted to represent a ground surface in each area portion (210); if such set includes at least two candidate surfaces, estimating a distance from the ground surface of each candidate surface by using a function of a set of geometrical features related to the considered candidate surface, such function being derived from a known relation between a digital surface model and the height of the ground surface in a reference area (215); selecting, as a representation of the ground surface in each area portion, the candidate surface having the smallest distance from the ground surface, so as to obtain local digital terrain models (220); and merging the different digital terrain models (225). |
