Application Of Whole Digital Close-range Photogrammetry In Large-scale Topographic Surveys

Close-range photogrammetry is an important branch of photogrammetry. It is superior to normal survey methods at quickly and real-time obtaining a great number of 3D coordinates and measuring objects which can not be touched. It can record instantaneous shape, size, position and state. Because digital close-range photogrammetry has the superiority that it can get object' s data easily proceeds data on real-time and high-level automatous and is used in wide range. The intentions of digital close-range photogrammetry are more quick and more accurate, from static to dynamic and from 2D to 3D.The emergence of the ordinary digital images (which in this paper means the digital images acquired by common non-metric digital cameras), resolved the the problem of acquiring images quickly on the spot, and lowered the requirement for equipments and skills in photogrammetry, so that made photogrammetry a whole digital process.In order to increase the adaptability and accuracy of digital close-range photogrammetry based on common digital cameras, researches and experiments have been done on these methods in this paper, as following:1. Probing into the basic theory and methods of digital close-range photogrammetry which based on non-metric digital camera: Direct linear transformation, Image matching;2. Expatiating on functions and characteristics of whole digital photogrammetry system VirtuoZo made by Supresoft.Inc;3. Exploring office and field operation procedure in application of whole digital close-range photogrammetry in topographic surveys.Researches and experiments illustrated that employing VirtuoZo system as office operation processing platform, the topographic surveys based on the ordinary digital images is feasible, and the accuracy of maps fulfils the requirement of surveying criterion. Digital close-range photogrammetry has applied in some large constructions of hydroelectric project such as XiaoWan hydroelectric engineering. This method hopes to change traditional operation mode of topographic surveys, and brings a new technique to replace the old ones in topographic surveys.