期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：1998
卷号：XXXII Part 4
出版社：Copernicus Publications
摘要：For the time being usual orthophotos do not place general 3D objects (buildings, bridges, etc) on their geometricallycorrect positions because conventional algorithms are based on 2.5D digital terrain models (DTM) thus limitingsignificantly the possibility of describing the real 3D shape of the objects and inhibiting the correct calculation of visibility.For large and medium scale image maps quite often the effect of wrong mapping cannot be tolerated any more and thegeneration of so-called true orthophotos becomes obligatory. In addition to the DTM 3D digital building models (DBM)must be introduced. Here three approaches are presented dependent on the complexity of the object surface. Themethods differ in the way to treat the DTM and DBM in the rectification process and in the visibility analysis. Open areaswith simple buildings do not need visibility analysis at all, while in urban areas with complex buildings visibility analysiswithin the DBM becomes compulsory. The most general approach performs a visibility analysis within the DSM (digitalsurface model) which is a common data base of DBM and DTM. A true orthophoto program has been developed, thatcan create all three types of orthophotos from aerial as well as close-range photographs
关键词：True Orthophoto; Building Model; Visibility Analysis
