For the current situation that the timber volume precision measurement was conducted by the felled standing tree method, the accurate measurement principle and experiment of timber volume by no-felled standing tree method has been carried out. Combining photoelectric theodolite, microcomputer and dedicated software, a tree measuring system was formed. The elevation angles of trees were measured by the photoelectric theodolite, the basal diameter and diameter at breast height of trees were measured through manual, and the diameter at breast height, tree height and diameter at anywhere of trunk were obtained with the dedicated software by indoor operation, then the timber volume was calculated. The statistical analyses on 99 trees (Poplar 108) belonging to Zhonglin Series were conducted, the results showed that the measured mean square errors of volume samples wereσmax=0.1303,σmin=0.0013, the variable distribution of the groups concentrated relatively, the discrete degree were small, Cv value was less than normal, Cs absolute value was smaller, while the positive bias and negative bias is equal;based on the measured volume values of 393 trees of Poplar 107 from 407 trees belonging to Zhonglin Series, a binary volume model was set up. The model was validated with the measured timber volume values of 12 trees, the maximum absolute value of the error rate was 10.1%, the minimum was 2.3%, the error meet the forestry tolerance requirements.
measurement of timber volume by no-felled standing tree methodphotoelectric theodoliteaccurate measurement principle
NETL
NSTL
万方数据
维普
