On analyzing system transformation errors related to differential GPS reference station

The position of a Chinese differential GPS (DGPS) reference station is already known in terms of Gauss-Kruger coordinates. Appreciable errors arise when Gauss-Kruger coordinate system has to be transformed into WGS84 coordinate system in order to make use of GPS signals which are based on WGS84. This paper shows the main cause of errors are due to measurement errors of the displacement components of one elliptical sphere center relative to another. The elimination of this main cause is helpful in improving aircraft landing accuracy.