Aerial triangulation data acquisition using a Low Cost Digital Photogrammetric System

Low Cost Digital Photogrammetric Systems (LC-DPS) are based on modular hardware and software, which fulfil standard map production requirements at a reasonable cost and offer most of the advantages of the digital technique. Algorithms and procedures for scanning aerial images by means of DTP scanners, the matching of selected points and automatic procedures for measuring DEM heights are now currently used. These instruments should be completed with a procedure for aerial triangulation data acquisition using the automation allowed by the recent development of digital techniques and modern PC performances. A software has been implemented and tested in order to perform the following procedures: automatic interior orientation, search of interest points and automatic selection of homologous points, robust validation and outlier detection by means the LMS estimator, automatic selection of image and strip tie-points. The algorithms and procedures are described in detail and the achieved results are shown in terms of quality and reliability.