Digital Orthophoto Generation with Aerial Photographs

Orthophoto process transforms a vertical aerial photograph in to the equivalent of traditional map. Yet it retains the advantages of a photograph-virtually displaying actual cultural and land features and the built environment rather than representing those features using symbols and lines. With the development of technology, Digital photogrammetry has started to be used widely in almost all areas about mapping. Especially digital orthophotos which are a photogrammetric products, are being used by lots of private sectors because of theirs easy interpretability. Several photogrammetric software which can be use to generate orthophotos are Leica Photogrammetric System (LPS), PCI Geomatica, Topcon pi 3000, Image Master, Erdas Imagine, VirtuoZo and others. In this study photogrammetric data from aerial photographs was used to generate orthophoto using erdas imagine software. The processing procedure of the system is described in detail. Sets of measurements (length and width) of selected buildings were obtained. The results obtained from this software are compared with ground survey measurement. The results showed that an accuracy of sub-meter of ±0.406m could be obtained from orthophoto generated using erdas imagine software. Conclusion is drawn concerning the suitability of the software for use in orthophoto generation. Future research is recommended based on two or more photogrammetric systems to comprise both side overlap and end overlap.