一种低轨双星高脉冲重复频率雷达信号的定位模糊消除算法

A Novel Method for Location Ambiguity Mitigation of High Pulse Repetition Frequency Radar Signal in Low Earth Orbit Dual-satellite Geolocation System

针对低轨(LEO)双星到达时间差(TDOA)定位系统中雷达信号的定位模糊问题,该文分析了高重频信号的模糊特性,演示了虚假定位点的产生过程,提出一种基于时差序列变化趋势匹配(VTMT)的定位模糊消除算法。在测量时差序列与定位结果对应的理论时差序列之间的残差近似服从正态分布的条件下,通过两个序列的欧式距离作为相似程度衡量依据,筛选出测量时差线与理论时差线最为接近的定位点作为目标辐射源真实位置。校验台测试信号验证了该算法的有效性。仿真结果表明,该算法能够显著提高无模糊定位概率,对长基线时差定位系统中雷达信号的定位具有较高的应用价值。

In order to mitigate the location ambiguity of radar signal in Low Earth Orbit(LEO)dual-satellite Time Difference Of Arrival(TDOA)location system,the ambiguous characteristics of high PRF signal are analyzed,the process of ghost location generating by ambiguous TDOA is introduced,and a method for location ambiguity mitigation by Variation Trendline Matching of TDOA(VTMT)is proposed.If the condition that the residuals between the measured TDOA series and the theoretical TDOA series corresponding to the positioning results approximately obey normal distribution is satisfied,the location where the measured TDOA line is closest to the theoretical TDOA line can be selected as the real position of radar emitter with the Euclidean distance being used to measure the similarity between the two series.Test signal of calibration station validates the effectiveness of the proposed method.Numerical simulations demonstrate that the proposed method can increase the probability of unambiguous location significantly,reduce the requirements of TDOA measurement accuracy and observation time.The proposed method has good prospect for applications to TDOA location of radar signal in long base line location systems.