Comparison of Terrestrial Laser Scanner with Digital Aerial Photogrammetry for Extracting Ridges in the Rice Paddies

The patches of the rice paddies are generally positioned by a traditional surveying method such as Plane Table and Total Station in Korea. This study has been undertaken to check whether TLS (Terrestrial Laser Scanner) could meet the accuracy standard, compare TLS survey data with those one of the new modern survey technologies such as digital aerial photogrammetry and RTK GPS. As a result, it is shown that terrestrial laser scanning and 3D stereo plot of digital aerial photogrammetry technology could meet a positional accuracy standard with artificial target. The extraction of ridges of rice paddies is, however, difficult due to the limitation of the tone colour identification and the noise of digital aerial image, and low density of the point clouds in TLS scanning. It is therefore expected that more researches into the sophisticated algorithms for the natural boundary extraction and the noise removal in digital aerial image are required.