Data quality influences directly on correctness and reliability of application

analyzing

decision-making of GIS

at present there is not much research on error of 3-D spatial data. This paper adopts spatial parallelogram to estimate uncertainty of arbitrary points inside and outside the spatial triangle plane

The estimate formulae of uncertainty of spatial triangle plane and normal vector are deducted. It indicates that spatial triangle plane constructed by three spatial points being not in the same beeline

the precision of arbitrary points inside its interior is higher than that of one of the three points at least. The precision of points on the margin of triangle plane is higher than that one of the two extreme points of the beeline at least. The precision of points outside the spatial triangle plane is distinctively lower. Triaxiality radius and direction of error ellipsoid of arbitrary points in spatial triangle plane is relative to variance and covariance

and to its position of inside this plane.