Comparison of Point Accuracies on Digital Elevation Model Obtained from Digital Air Photographs with Different Specifications

Abstract

Photogrammetry is a map production technique or science applied by measurements made from terrestrial images with terrestrial cameras or more commonly used images taken with airborne cameras. With the development of technology, digital photogrammetry has been widely adopted in almost all areas of mapping. Especially digital orthophotos and digital elevation models, which are photogrammetric products, are being intensively utilized by the private sector due to their easy interpretability. Digital photogrammetry is also a good method to automatically collect digital elevation models. Digital elevation model production is an important process in photogrammetry. A digital elevation model is an important product by itself as well as plays an important role in creating products such as orthophoto. The geometrical accuracy of digital elevation model used in geomatics applications is of even greater importance. In this study, three different digital elevation models were produced using digital aerial photographs of 7 cm, 15 cm and 25 cm ground sample distance taken in 2011 of Aksaray University campus area. Then, by using the heights measured by GPS and read the same heights from the digital elevation model, root mean square errors of ground control points, check points and tie points were calculated and compared with recommended standards. When the results are examined, it is seen that the values were close to and below the recommended values. Therefore, it can be seen that the digital elevation models produced with the aerial photographs taken at 7, 15 and 25 cm ground sample distances can be used for studies that do not require.