A comparison of remotely sensed terrestrial spatial information

Abstract

[Abstract]: Today's users of spatial data request information sooner, more accurate and safer than ever before. New technologies equip spatial professionals with the ability to achieve this. Terrestrial laser scanning and terrestrial photogrammetry offer similar advantages when it comes to remotely sensed data acquisition. Terrestrial photogrammetry has a history of use as a remote sensing tool, and with the emergence of cheaper, high quality digital cameras; photogrammetry has become accessible to a wider range of users. Terrestrial Laser Scanning is comparably new to the spatial science industry, with its many advantages fast becoming recognised by professionals. Its usability is limited to the economic cost of the scanner and the surveyor's confidence in their ability to guarantee the data captured by the scanner. This project will seek to compare the accuracy that can be expected from single point measurement for both technologies. The testing included a grid of targets that was used for both technologies. These targets were coordinated by Total Station with reflectorless EDM. Three of the targets were used to orientate the information collected from the two technologies to a common reference system, with coordinates of the points not included in the orientation directly compared to the original coordinates. The results of this project validated the superior accuracy of the terrestrial laser scanner. Results also indicate that terrestrial photogrammetry offers reasonable accuracy levels suitable for many functions as a low cost alternative.