双星时差频差定位体制在频域混叠电磁环境下的应用

现代战场电磁环境复杂，不同类型电磁信号在时频域碰撞混叠，现有常规侦察手段对此类信号的定位应用受到严重制约。双星时差频差定位体制通过互模糊函数求解信号到达时差和频差，分离频域混叠信号并获得高达公里量级的定位精度，非常适合于复杂电磁环境下的应用。通过求解模糊函数的方法分析了时差频差体制对频域混叠信号的分离和定位能力，然后结合美航母编队及其电磁环境构成，探讨了这一能力在监视航母编队，尤其是跟踪识别编队个体成员的具体应用。仿真与分析结果证明了双星时差频差定位体制的优势，对于天基侦察系统的建设具有重要意义。

Application of dual-satellite geolocation system using TDOA and FDOA in electromagnetic environment of signal mixed in frequency domain

In modern warfare, battlefield has complicated electromagnetic environment, where various electromagnetic signals collide with each other in all probability. It''s very difficult for ordinary intelligence, surveillance and reconnaissance(ISR) systems to positioning these interlaced signals in frequency domain. The dual-satellite geolocation system using time difference of arrival (TDOA) and frequence difference of arrival (FDOA), which calculates the TDOA and the FDOA by crossing ambiguity function, can separate all interlaced signals in frequency domain and locate them with high accuracy up to kilometer level. It shall be suitable for applications in complicated electromagnetic environment. This paper analyzes the separation and positioning capability of TDOA/FDOA scheme for interlaced signals in frequency domain by the method of solving ambiguity function,and then,according to the composition of U.S. carrier battle group and its electromagnetic environment, discusses the application of this capability in observing carrier battle group, especially tracking and identifying individual member of carrier battle group.Simulations and analysis prove the advantage of this system and it is of great significance for constructing China''s space-borne ISR system.