MEASUREMENT OF PHYSICAL ENVIRONMENTS OF RIVER WITH TERRESTRIAL LASER SCANNING SURVEY

Abstract

Several algorithms are developed for terrestrial 3D laser scanner system coupled with digital photogrammetry to be applicable for the measurement of river physical environment. The data by terrestrial laser surveying is compared with those by ground surveying in the Minochi River. It is shown that high Green value identifies vegetation areas and low value of reflected light intensity identifies water surface areas, which yields an effective algorithm for land-cover classification in rivers. To remove virtual image data on water surface, which is peculiar to terrestrial laser surveying, a robust algorithm is developed with an estimation method of water surface profiles. And a new estimation method that relates the deviation of ground level to the surface grain size is also devised.