差分 GPS 基准站坐标系统转换误差分析

On Analyzing System Transformation Errors Related to Differential GPS Reference Station

讨论了差分ＧＰＳ基准站设计中的坐标变换，推导了坐标变换误差的计算式，分析了它们对ＤＧＰＳ精度的影响。计算结果表明坐标变换对ＤＧＰＳ的影响主要来自参考椭球中心平移量误差，提高参考椭球中心平移量的精度是消除坐标变换误差对ＤＧＰＳ精度影响的关键。

The position of a Chinese differential GPS(DGPS) reference station is already known in terms of GaussKruger coordinates. Appreciable errors arise when GaussKruger 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 presents the main cause of errors due to transformation we found after careful analysis. The elimination as much as possible of this main cause is believed to be helpful in improving aircraft landing accuracy in China. Mathematical derivation was rather involved, so we eliminated a great deal of details and now present only an outline. We employee eqs.(5), (8), (10), and (13) in calculations. Δ 2 x , Δ 2 y , Δ 2 z in eq.(13) were the errors due to insufficiently accurate measurement of the displacement components of one reference elliptical sphere center relative to another. For our calculations, we made the reasonable assumption that they were all 10 m. In Table 1, we listed the x, y ,h values (or GaussKruger coordinates) of four points in China. In Table 1, we also listed the Δ x WGS , Δ y WGS , Δ z WGS , which were the calculated errors due to transformation from GaussKruger coordinate system into WGS84 coordinate system. Table 1 shows clearly that the transformation errors are due mainly to measurement errors of the displacement components of one elliptical sphere center relative to another.