林地面积的手持GPS量测

通过秩亏自由网平差原理对手持式GPS接收机测量的坐标值进行平差,旨在提高手持式GPS测量地块面积的精度。实验证明,用秩亏自由网平差法求算面积的精度,有效地考虑了各点的误差,虽然计算过程很复杂,但是通过VisualBasic编制的程序可以很快完成面积计算、精度评定等工作。虽然手持式GPS有一定的定位误差,但是通过皮尺测距有效地控制了其误差,提高了观测精度,可广泛应用于林分面积量测及地类变化监测。

Forest stand area surveying with hand-hold GPS receiver

Through adjusting the coordinate data surveyed by hand hold GPS receiver with the principle of rank defect free network adjustment, the aim of author's study is to increase the precision of hand hold GPS when surveying the block area. The experiment in this paper proved that the method of defect free network adjustment evaluates each point's error, and the program wrote in Visual Basic by the author can quickly finish the adjustment, area calculation and precision evaluation.The error created by hand hold GPS can be controlled and the precision is increased through surveying distances with ruler. So the surveying can be widely used in surveying and supervision of forest land variation.