Digital Terrestrial Photogrammetry

Terrestrial photogrammetry is engaged in measurement, contour delineation or 3D reconstruction with photos captured by a camera located on the ground. Terrestrial photogrammetry has gained wide applications in many fields such as 3D building reconstruction, heritage protection and so on. In this paper, a new instrument named photo total station system has been adopted and meanwhile based on this new instrument, a flexible and efficient digital terrestrial photogrammetry method has been developed. Photo Total Station System (PTSS) is a completely novel surveying system, which installs metric digital camera on total station to compose an integration system together with digital photogrammetry software. PTSS takes full advantages of mature digital photogrammetry techniques and accurate total station survey method and provides the benefits of both systems, while minimizing their shortcomings. The whole process of digital terrestrial photogrammetry includes two stages: field survey and indoor photogrammetric processing. Depends on specific measurement condition and requirement, three measurement modes can be selected to use so that the whole measurement process can be very flexible. After field survey, all measurement data including images are processed by attached photogrammetry software whose unique characteristics are presented in the paper: such as multi images based image matching (short base) are used instead of stereo based one in the conventional photogrammetry; using so called control bars setting near the camera instead of regular control points -- a real non-contact measuring method can be implemented so that control points around or on the measured object can be reduced or completely unnecessary. With this technique, DTM and contour gene..