EVALUATING PARAMETERS AFFECTING THE GEOREFERENCING ACCURACY OF TERRESTRIAL LASER SCANNERS

Abstract. Today laser scanning is used as a powerful technology in measuring various simple and complex objects in cultural heritage applications. Depending on the size and the complexity of the objects, these measurements are usually made from several stations. Similar to all other surveying techniques, the coordinate systems of such measurements need to be registered. For this, a number of retro-reflective targets visible from different stations are used. In practice, the target centres are entered in the computations. The accuracy of the target centres, therefore, need to be high or the final object coordinates might not be of sufficient accuracy. A number of factors including the distance between a target and the laser scanner, the direction of the target surface with respect to the laser scanner beams, the intensity and the number of reflected laser beams affect the accuracy of target centres. In this paper, various tests are carried out to examine the effect of such factors on the accuracy of coordinates obtained for the target centres. The results show that the distance to the laser scanner and the angle between a target surface and the corresponding laser beams have considerable effects on the locational accuracy of the targets.