森林面积测量精度对比分析

通过在贵州山区（花溪区）不同林地条件下选设的多个点上进行面积测量试验，以全站仪测量结果为参考，对比分析实时动态GPS和罗盘仪在小班面积测量中的精度问题。研究表明，在进行森林资源调查小班面积测量时，其罗盘仪测量精度较GPS高；但是随着面积增大，GPS面积测量相对误差减小，而罗盘仪测量误差相对呈增大的趋势，并且测量精度明显低于GPS测量。GPS在对有林地、灌木林地、疏林地进行面积测量时，受林分郁闭度影响较大，其精度随着林分郁闭度的增大而降低；而在草地和无林地中无明显影响。由于目前采用的GPS单机定位精度不够高，所以不能用单机进行林业用地小地块面积测量，宜用GPS差分定位技术测量。

A comparative analysis of area surveying precision in different stand

Area measurement,in different stand in Guizhou mountainous area, was experimented with real-time kinetic GPS receiver and compass and total station instrument in this paper. Tile area surveying precision of GPS in forest subcompartment was compared compass referenced with total station instrument. The result showed that the precision of compass was excelled that of handset GPS in a small area. The error of GPS was less than that of the compass in large area. Crown density distinctively influenced the area surveying with GPS in forest, shrubby and woodland and the error was increased with crown density. Single GPS receiver could not be applied in a small area surveying, but the real-time kinetic differential GPS instead.