Study On Application Of Forest Parameter Extraction By Digital Photogrammetry

Forest resources survey is an important component of forest resources monitoring system of China and Heilongjiang province. Forestry mapping and plant resources measurement in use of aerial photographs is the main task of plant resources survey. Color aerial photographs could reflect and record the truly color or grayness of forestry character. It had high resolving power and steady-going determined character. So it had very important function in the forest aerial survey technology.Based on the theory of the Bundle Block Adjustment, this paper used digital photogrammetry workstation VirtuoZo system to interpolate the controlling points by aerotriangulation method for 193 charts, totally about 12 sea-routes of the trial forestry centre in Liangshui of NEFU in September 2008. After model orientation and ortho-rectified to original photographs, at last the Digital Elevation Model (DEM) and Digital Orthogonal Map (DOM) with the 1:10000 scale were generated. The resolution ratio of DOM is 1.0m, reaching quite high precision and responding to the request in mountainous area.Corresponding to outside monitoring area in study district, plots were chosen and digitally measured in stereo models or on DOM. By simply comparing the results of digital mapping and the outside monitoring data, the result showed it was possible to survey and measure part forest factors supported by the ArcView software and the aerial photograph. This study was a practical application to forest survey using photogrammetry, RS and GIS, and paved a way for the forest attempt to evaluate management.