Effect of Elevation Error on Accuracy in 3-D Coordinate Transformation

Based on Bursa-Wolf coordinate transformation model and parameter solving methods,a mathematical model for the 3-D accuracy of coordinate conversion for arbitrary measured point in the surveying area is derive with the theory of error propagation.According to the analysis of the mathematical model,it can be concluded that the variation of conversion accuracy of measured point presents a parabola distribution with the change of altitude.Meanwhile,when the variation of altitude is in the scope of-100~1 000 m,the conversion accuracy is about 10-2 m,which has a trivial effect on the coordinate transformation.The theoretical validity of the conclusions was proved by experiment.