| Abstrakt: |
Personal laser scanning (PLS) has shown great potential in diameter of breast height (DBH) estimation. Compared with the current laser scanning technique, PLS is hardly restricted by occlusion and trafficability, and produces omnidirectional point cloud data. However, the DBH estimation accuracy using PLS data was not higher in the previous research. One of the leading sources of bias is overlapping and inaccurately co-registered point cloud fragments. Points of these fragments can be far from the stem surface, which leads to a large bias in DBH estimation. In this letter, a novel DBH estimation method using PLS data, the stem surface node method (SSN) is proposed. To reduce the impacts of the inaccurately co-registered points far from the surface, SSN attempts to use a number of stem surface nodes in polar coordinates instead of the whole stem point cloud to estimate DBH. Six plots with 247 stems under three different working conditions were selected to evaluate the method. Compared with the DBH estimation method using direct circle fitting, SSN achieved a total error reduction of 62.64% and 38.35% for bias and root mean squared error, respectively. These findings confirm that SSN is generally reliable and adaptive for different kinds of working conditions. [ABSTRACT FROM AUTHOR] |
