area-point sampling

The results indicated that it is unbiased to estimate basal area of stand but inefficient when estimating stems per hectare by point sampling.

结果表明：点抽样估计林分断面积是无偏的，而估计林分每公顷株数效率不高。

The GVG system is a new solution, with the conception of sampling lineage instead of the traditional sampling point or sampling area, to extracting crop acreage information.

线采样系统提出以线状样区代替以往成数抽样中的点样区与面积样区概念，通过统计线状样区内作物种植面积成数来反映区域总体农作物种植面积成数。

A key difference is that this algorithm does not give the same value at the sampling point but gives the same average value in unit area of each pixel.

此算法的关键不同点在于不是让算法结果在采样点的值等于原采样值，而是在一个象素大小的单位面积上得到的平均值等于原采样值。