Precision of Points Computed from Intersections of Lines or Planes

Not all points are directly accessible when doing detail surveys wirh GPS. This paper gests a method for estimating these points. The points are computed from intersections of lines that are surveyed with GPS. The lines are computed by least squares estimation. Further, the suggested method estimates the precision of the points. When using laser scanning a similar problem appears. A laser scanner captures a 3-D point cloud, not the points of real interest. The suggested method can be used to compute three-dimensional coordinates of the intersection of three planes estimated from the point cloud. The method can also be used to predict the precision of the points prior to a survey. An example is given.