THREE DIMENSIONAL VISUALIZATION OF FOREST USING FIELD MEASURED DATA, SATELLITE IMAGE AND FISH-EYE PHOTO

摘要

Forest composed of many trees has an important role in maintaining environmental conditions suitable for life on the earth. There are many research which incorporate tree survey data into geographical information system, but those are not represented individual tree objects. A purpose of this study is to build the three dimensional forest map of individual tree level, by fusion of field measured data, satellite image, and omni-directional fish-eye photos. First, to obtain the field measured data, we have collected several kind of tree data in the test site. This area is 140 meter from west to east and 60 meter from north to south. In this site, the grid of 10 meter mesh is constructed using piles labeled alphabet and numeric characters. In this study, about 100 trees with height of 16 to 18 meter were selected in order to measure. The measured data are the tree stand locations, the eight distances between the tree trunk and outermost branches in eight directions, and the diameter at breast height. Second, we create the three dimensional forest space using OpenGL graphics library. By using the field measured data, each octagonal crown object which has the location and outermost shape of individual tree is created. The method of image-to-map rectification to identify tree crown from satellite image is performed for registration of high corresponding. The each registered region in IKONOS satellite image is rendering on the corresponding crown object. Next, using omni-directional fish-eye photos taken at the four viewpoints on the corners of the each grid, the rectangle trunk objects of four different directions are created. Finally, it became possible to visualize the three dimensional forest map of individual tree objects with attribute data. By using omni-directional fish-eye photos taken at different seasons, it is possible to show seasonal change of individual tree in forest. This system is useful for forest management and monitoring.