几种测量方法在森林资源调查中的应用与精度分析

通过外业调查数据分析和理论推导,对林业调查中的几种测量方法进行了比较分析。研究表明：①罗盘仪由于制作粗糙,在标准样地测设中尚能满足规范要求,但随着距离和竖直角的增加,精度急剧下降,在大范围的林地面积和科研特殊需要的测量中操作不便捷,精度差,效率低;②全站仪测设样地边长不超过100 m时,半测回的距离测量可达到1/10 000,高差测量误差不超过1 cm,且受距离和竖直角的影响较小;③当面积大于3.34 hm^2,边长超过100 m时,手持全球定位系统（GPS）完全可代替罗盘仪,并可通过坐标差分或修正坐标转换参数来提高测量精度。另外,网络RTK的发展必将连同全站仪成为精准林业测量的主要仪器设备。

Application and precision analysis of several surveying methods in forest resources survey

This paper compares and analyzes several surveying methods in forestry resource investigation via an analysis of experiment datum and theory reasoning. The research findings are as follows： （1） The compass could only satisfy the criteria and standards of surveying sample plot due to its roughness; and its accuracy would decrease significantly while distance and vertical angle increased; the compass was inconvenient, imprecise and inefficient for large scale forestry acreage survey or special scientific research. （2） When the length measured by total station was not over 100 m, semi-observation accuracy of distance measuring could reach 1/10 000 and height measuring error wouldn＇t be over 1 cm; and the measuring was hardly affected by distance and vertical angle. （3） When acreage and length were over 3.34 hm^2 and 100 m respectively, handy global positioning system （GPS） could replace compass, and its measuring accuracy could be improved by coordinating difference or modifying parameter of coordinates transform. Besides, development of network real time kinematic （RTK） with total station would be main instruments for the precise forestry surveying. [Ch, 2 tab. 13 ref.]