基于GDOP的四星时差定位精确度分析

Precision analysis of four-satellite TDOA location based on Geometric Dilution of Precision

针对四星时差定位系统,提出一种基于几何精度衰减因子(GDOP)的定位精确度分析方法。该方法基于四星时差定位原理推导三维定位精确度模型,理论分析时差测量误差与站址误差对该三维定位精确度模型的影响。通过仿真验证四星不同布站情况T型、Y型、方型及不规则型对定位精确度的影响,并进一步研究在不同布站情况下的基线长度、卫星轨道高度、目标高度等对定位精确度的影响。仿真结果表明,四星时差定位在Y型分布时具有最佳的定位精确度;并且定位精确度随基线长度与卫星轨道高度的增加而提高,随目标高度的增加而降低。

A precision analysis method of four-satellite Time Difference Of Arrival(TDOA)location based on Geometric Dilution Of Precision(GDOP)is proposed.Firstly,the 3D location precision model based on TDOA is investigated.Then,the influences of the time measurement error and location error on the above precision model are analyzed.Finally,the GDOP of representative four-Satellite of Y,T,square and anomaly are simulated.The influences of the length of baseline,the satellite and target altitude on location precision are analyzed.The simulation results show that four-satellite location of Y distribution based on TDOA achieves the best precision.The increase in the length of baseline and satellite altitude contributes to improving the precision of location.