Photogrammetry

This chapter shows the automatic exterior orientation procedure and reconstruct the three-dimensional model for the low-cost unmanned aerial vehicle (UAV) photogrammetry. Photogrammetry technology has developed with aerial photogrammetry for mapmaking and terrestrial photogrammetry, which measures and surveys the ground with metric camera. Digital photogrammetry is the digital photo technology, which replaced film-based data with digital data to integrate with the image-processing technology. The basic principle of photogrammetry is based on photo image, center of projection, and the geometrical condition called colinearity condition, where the objects should be on the same straight line. In digital photogrammetry, they are of three different types: single photogrammetry with one single photograph, stereo photogrammetry with two photographs as one unit, and photogrammetry with many photographs. The low-cost UAV has become useful tool for low-altitude photogrammetry from the rapidly increasing automatic control technique.