中文摘要：

针对地球模型精确度影响远程弹箭弹道仿真的问题，分析了地球模型偏差对弹道仿真精度的影响并加以修正。采用总的地球椭球系，在已有弹道模型的基础上，分析了垂线偏差的产生机理及其对定向定位参数的影响，并由此得出弹道几何偏移随定向偏差的变化规律，研究了引力加速度初值偏差对弹道的误差累积，并对由水准面不平行性造成的实际落点高差进行了理论推导。对比仿真算例表明，考虑地球模型偏差影响的仿真结果与不考虑的情况下差别较明显，在远程条件下对弹道仿真精度的影响不容忽视。

英文摘要：

The precision of earth model influenced the trajectory simulation of long-rang missile. Aiming at this problem,the effect of earth model deviation on the simulation accuracy is analyzed and the correctional method is presented. Adopting the model of all ellipsoid, this paper analyzes the generation mechanism of plumb-line deflection which affects the parameters of orientation and presented the changing regularity of ballistic geometry migration. Meanwhile, the accumulation of ballistic errors due to the initial deviations of gravity acceleration is studied and landing height difference stem from the non- parallelism of level surface is deduced theoretically based on the existing model trajectory. The contrastive examples indicate that the calculated results are obvious different in both cases. The factors which impact the precision of simulation should not be ignored in the calculation of long-range missile.