中文摘要：

从球对称引力场中光子在赤道面上的运动微分方程出发，采用后牛顿近似方法，讨论了Reissner—Nordstrom度规场中雷达回波延迟实验的后后牛顿修正．通过计算给出了后牛顿以及后后牛顿的修正结果，当荷电量Q为零时，该结果适用于电中性天体，其后牛顿部分的修正与经典文献一致．文中采用的近似展开方法同样适用于讨论更高阶的修正．雷达回波的高阶修正对目前展开的高精度空间引力试验有着重要的参考价值．

英文摘要：

From the kinetic differential equations of the photon in the equatorial plane of the spherical symmetrical gravity field, the post-post-Newtonian amendments for radar echo delay test in the Reissner-Nordstrom field are discussed using the post-Newtonian approximation method. The amendatory results of post-Newtonian order and post-post-Newtonian order are deduced in this paper. When the charge Q is equal to zero, the results are applicable to neutral celestial objects. The post-Newtonian amendatory parts are consistent with the classical literature. The approximation method used in this paper can also be used to discuss the amendments with higher orders. The high-order amendments for radar echo delay test have important signifieances to the ongoing high-precision spatial gravitation test.