Comparison of 3d models obtained by high resolution terrestrial laser scanning and terrestrial photgrammetry data

Nowadays 3D documentation of cultural heritage and engineering projects became an important matter. In these documentation applications, an accuracy and detail requirement of the subject has to be as high as possible. Thanks to the developments in computer science, terrestrial photogrammetric methods are using in 3D documentation applications. Terrestrial laser scanners gained popularity in this last decade because of their high capacity and today they are being widely used in many projects. In the applications, Leica C10 time of flight laser scanner used as terrestrial laser scanning equipment and Canon Eos 550d is used for the terrestrial photogrammetric purpose. In this study, laser scanner and terrestrial photogrammetric methods' spatial and model accuracies under various scenarios has been investigated. These scenarios are, measuring targets at different instrument to object distances then investigating the accuracy of these measurements, modeling an irregular shaped surface to compare two surfaces volume and surface areas, at last comparing dimensions of known geometrical shaped small objects. In this study, terrestrial laser scanners and terrestrial photogrammetric methods' most suitable conditions investigated in terms of cost, time, portability and accuracy. Terrestrial laser scanner has the ability to, measure distances below cm accuracy and directly measuring 3D world but there is also some drawbacks like sensitive, bulky and expensive equipment. When it comes to terrestrial photogrammetry, it has above cm accuracy, fast, inexpensive but it can be affected by the coarse geometry, surface texture and the environmental lighting. Key Words: Accuracy, Volume, Comparison, Model, Terrestrial Photogrammetry, Terrestrial Laser Scanning, Surface.