Forest Resource Precise Measure Techniques And Automation

In order to automatically and accurately measure individual tree and stand at real-time, this paper mainly researches several problems as following which are solved by programs wrote in embedded Visual C++3.0 based on PDA: firstly, how to accurately measure individual tree; secondly, to measure stand by the reason of angle gauge; lastly, to measure stand volume with 3P sampling.Today, forest resource is badly decreasing, so it is especially import to accurately measure individual tree and stand without injury. This study adopts electronic theodolite or total station as tools, writes program in eMbedded Visual C++3.0 based on PDA, to accurately measure individual tree's diameter of breast height, tree height, diameter of any transect and its' height, stem volume, crown volume and its' superficial area.To decrease the error of surveying tree using general angle gauge, this paper put forward basic theory and method of measuring forest volume and increment with electronic angle gauge. Electronic angle gauge is organic combination of electronic theodolite and personal digital assistant. It can accurately survey forest basal area by reason of precise angle-surveying of electronic theodolite and corresponding PDA program. Through real-time and accurately surveying tree volume, electronic angle gauge can account form height of this tree, accordingly, it can account stand volume. Moreover, electronic angle gauge can accurately survey the grades between trees and angle gauge point for grade rectification. The authors of this paper set up fixed stake and survey twice on it to get stand volume increment. For reasonably explaining increase of forest volume, the authors import the method of latent number counting, which can reasonably account the latent volume of ingrowth trees on prophase. Forest volume increment is the increment summation of reserved tree, ingrowth tree and latent tree.As a method of stand volume investigating, 3P sampling technology has been accepted in forestry field, but for the reason that two critical problems, stand volume precise monitoring and random data fast generating can't be solved well in traditional forestry resource monitoring, the technology has not been used widely for a long time. We have realized precise measuring stand volume with electronic angle gauge, adopting the method of subsection integration to estimate the tree volume, and we also developed a 3P sampling program which will generate random data corresponding to assistant parameter. In a word, the result of this study makes it more convenient and simpler to carry out the 3P sampling. In Dangchuan Forest Farm of Xiaolongshan Forest Bureau Gansu province, we have made many relevant experiments, and high monitoring precision is achieved.This study is to eliminate the shortcomings in our country's forestry investigation, such as rough, forceful injury to forest and emphasize particularly on theory while despise instrument.