RTD GPS量测林地面积的模拟试验

为研究林地面积与森林蓄积量的估算精度,以RTD GPS(实时差分全球定位系统)为主要工具,通过对面积大小不同、形状规则的地块进行试验研究,对测量结果进行了相对中误差、标准方差、精度的计算和分析.结果表明:最低的测量精度达到97.67%,能够满足各类森林资源调查中林地面积测量的精度要求,并且随着测量面积的增大,RTD GPS的测量精度逐渐提高;采用实时差分定位的缺点是必须到现地观测,这对于大面积森林调查是不现实的,根据林地调查的实际分析,RTD GPS适用于林地面积传统调查(图上勾绘等)的实地精度检验,这种方法较传统的检验方法快速高效,而且能够保证精度.图1表2参8

Simulation experiment of surveying forest land area with RTD GPS

To study the precision of calculating forest land area and forest volume, lands of different areas and regular shapes were tested with real-time differential GPS (RTD GPS). The relative errors, variances and precision of the surveying results were calculated and analyzed. The results showed that the minimum surveying precision was 97.67%, which could satisfy the precision demand for forest land area surveying in the study of various forest resources. With the increase in surveying area, the surveying precision of RTD GPS tended to improve. However, RTD GPS had its defect because the surveyors had to conduct on-the-spot survey, which was impractical for the survey of forest land of a large area. According to the actual analysis of forest land survey, RTD GPS is applicable to the precision test of the traditional survey of forest land area. It is more rapid and efficient than the traditional testing method and can ensure the precision.