Evaluating the relationship between scanning resolution of laser scanner with the accuracy of the 3D model constructed

A 3D laser scanner is an active image capturing instrument that has the ability to accurately send a signal and capture it back in x, y and z dimension. The then can be used to produce the real surface condition in relevant processing software which is suitable for direct measurement on the image or constructing DTM (Digital Terrain Model) the as what is possible in photogrammetry. A 3D laser scanner captured image the same as photogrammetric camera that capture x and y coordinates and z value measured by distance from the instrument to the object. As the development of computer technology become so advanced the capability of software to handle images captured with certain overlapping coverage to produced 3D model has been proven capable of producing a high quality surface model as the raw data captured in 3D with instrument coordinates system. The principal used in laser scanning technology is the same in photogrammetry but the different is the laser scanner can measure distance from the object to the centre of the instrument as well as it offer a different scanning resolution and wider angle of coverage which is not available in normal camera used in close range photogrammetry. When the laser scanner scan a object it actually calculate the a 3 dimensional coordinate for each pixel on the object based on the principal of 3D triangulation since it measure distance, angle and high of instrument provided by user. A surveying technique for acquiring positional data to construct DTM (Digital Terrain Model) such as laser scanner should be evaluate the impact of scanning resolution in order to relate the scanning resolution and the accuracy of the surface model for a GIS or any other application. The technique of producing 3D model and the size of spatial pixel captured during observation must relevant to the cost of producing and accuracy requirement of the client. This paper will study the impact of scanning resolution on the accuracy of the points on the ground by comparing the coordinate obtained with 3D scanner with GPS static observation.