星下点构型对目标定位精度的影响分析

Analysis of Influence on Target Positioning Accuracy under Sub-satellite Point Configuration Application

基于TDOA/FDOA对地面辐射源目标的定位原理,建立了多星TDOA/FDOA联合定位模型和定位精度分析模型。针对三星和四星系统不同星下点构型,仿真分析了星下点构型对目标定位精度的影响。三星星下点构型包括星下点直线型、等腰锐角三角形、等边三角形、等腰直角三角形、等腰钝角三角形等5种情况。四星星下点构型包括直线型、三角形、凹四边形和凸四边形等4种情况。分析结果表明,增加卫星数量能够提高探测区域内目标的定位因子和定位精度;星下点非直线型的三星及四星构型,定位精度优于直线型构型,各卫星之间的基线长度尽可能长。

Based on the principle of ground radiation source positioning by TDOA/FDOA, a multi-satellite TDOA/FDOA joint positioning model and a positioning accuracy analysis model are established. Simulation analysis is made to analyze the influence of sub-satellite point configuration on target positioning accuracy under different sub-satellite point configurations in three and four-satellite systems. Sub-satellite point configurations in three-satellite systems include five types known as linear type, isosceles acute triangle type, equilateral triangle type, isosceles right triangle type and isosceles obtuse triangle type. Sub-satellite point configurations in four-satellite systems include four types known as linear type, triangle type, concave quadrilateral type and convex quadrilateral type. The results suggest that the increase in the number of satellites can improve the positioning factor and target positioning accuracy in the detection area. Non-linear types of sub-satellite point configuration in three and four-satellite systems have better performance than linear types in positioning accuracy. The baseline length among satellites has to be as long as possible.