The investigation accuracy of orthophotos generated from digital air images recorded from different heights

Digital orthophoto maps are numerical products that combine the accuracy of maps and readability of aerial photographs. They are prepared using colored or black and white digital aerial photographs and they have a fixed scale like maps. Digital orthophotos offer more flexible, cost-effective, and higher-quality outputs than classical methods. Today, the need for up-to-date maps is increasing in almost every field, and as an alternative to classical methods, orthophoto maps meeting the criteria of accuracy and precision of a standardized map are mostly preferred in a wide range of applications. However, the geometrical accuracy of orthophoto maps used in geomatics applications is of even greater importance. This study compared the orthophoto maps, that have a fixed scale like maps, obtained from digital aerial photographs at a ground sample distance of 7, 15 and 25 cm in 2011 in the campus area of Aksaray University, in terms of their positional accuracy. Orthophoto mosaic images were created using "Erdas LPS" software. The accuracy results obtained were compared with the values recommended in national and international standards It was also concluded that the positional accuracy of orthophotos for all three ground sample distances was suitable for use as reference and as a base in all application areas, for those requiring very high accuracy.