The Influence Of Photo-control-network Design To Aerotriangulation Accuracy Based On UCE Image

The current field surveying specification of aerial photogrammetry has been clear requirements for the density of photo-control-points of traditional photogrammetry that is based on film images.But it doesn't have clear provision for the density of photo-control-points of aerotriangulation that is based on multilens composite digital images.Therefore,it has important practical implications for finding an economic and reasonable designing scheme of photo-control-network in actual production is especially important.This paper takes the example of a gentle hilly area of 270 square kilometers and the aerotriangulation of 1:1000 scale photogrammetries that is based on the UCE digital images,to carry on 14 different densities of the photo-control-points layout scheme with increasing the density.Using the network RTK collect the plane coordinates and the height coordinates of photo-control-points.And the normal aerotriangulation and POS supported aerotriangulation for these 14 layout scheme were carried out by Inpho system.Draw the following conclusions.(1)The thinner density of photo-control-points,the less workload of field surveying,but the accuracy will be reduced.The results of aerotriangulation fail to meet the accuracy requirements of photogrammetry,when the density of photo-control-points is low to a certain extent.(2)For the normal aerotriangulation,it can meet the precision requirement only need to layout 25-28 photo-control-points in this gentle hilly area of 270 square kilometers.At this time,the density of photo-control-points is about one point per 10 square kilometers;the number of photo-control-points can be reduced by about 40% compare with the traditional photogrammetry.(3)For POS supported aerotriangulation,it can meet the precision requirement only need to layout 4 photo-control-points in this gentle hilly area of 270 square kilometers which was operated by skilled operator.At this time,the density of photo-control-points is reduced to one point per 70 square kilometers;the number of photo-control-points can be reduced by more than 90% compare with the traditional photogrammetry.