Simulated Photogrammetric Data for Testing the Performance of Photogrammetric Instruments and Systems

Abstract

The generation of mathematical photograms (photos) as data is universally accepted as the basis for photogrammetric studies. New development in the field of computer technology has had a major influence on photogrammetry. This paper aims to describe the development of a computer system called SimuPhotos designed to produce simulated data in different forms for testing photogrammetric methodologies, software, and instruments. SimuPhotos is capable of generating photogrammetric blocks with different specifications. It generates the simulated data for the whole block, strips, or selected photos. The simulated free error data include the camera interior orientation parameters, ground coordinates of points, and for each photograph, camera exterior orientation parameters, and the photo coordinates of imaged points. To increase the capabilities of the developed system, it has a special error generator to get normally distributed error(s) with arbitrary mean(s) and standard deviation(s). The obtained errors are then, if required, applied to the error-free photo and ground coordinates of points. The developed system interfaces CAD technology to generate simulated photogrammetric data in DXF and raster formats which are suitable for testing the photogrammetric instruments and softcopy systems. SimuPhotos has been used for testing the analytical photogrammetric system PhotoMap. The results showed that PhotoMap is free of system error and is functional. Also, the results showed that SimuPhotos can effectively provide a convenient, economical, and accurate testing tool for photogrammetric systems. The developed system is quite versatile and affordable.