Study On Location Algorithm Of High Speed Near-Space Vehicle To Ground Target

Near-space is an important strategy space and urgent need to development, especially, the vehicle of near space has unique military advantage, such as good reconnaissance warning, communications relay, navigation and information warfare ability, so the near-space research has become a hot spot and concerned by many country.This paper mainly study passive location technology of high speed near space vehicle to ground targets, and mainly analysis the location principle, observability, and research the nonlinear filtering algorithm. The main contributions in this paper are illustrated as follows:(1) The comprehensive description about the research background and significance of near-space single station location are elaborated, and makes a systematic summarized about the current status of abroad and domestic. Besides, some correlative knowledge on the signal station passive location is introduced.(2) The location principle of traditional signal station passive location algorithm is analysis. Especially, the location algorithm based on phase difference rate of change and the location algorithm based on doppler frequency rate of change have been researched.(3) The location algorithm based on phase difference rate of change can not measurable when target and vehicle all with uniform linear motion or similar movement, as well as, the location algorithm based on Doppler frequency rate of change need to use complex process approximate angle rate of change. Aiming at this problem, a location algorithm which combined the phase difference rate of change and Doppler frequency rate of change is presented in this paper(so-called PFRC algorithm). By making use of the phase difference rate of change which can direct measurement to replace the angle rate of change in the location algorithm based on Doppler frequency rate of change. The proposed method can not only effectively simplify computation in the measurement process, but also can reduce requirement to vehicle mobility. Then through single location simulation to verify the feasibility of the algorithm. Considering the problem of low precision of single location, a extended kalman filter algorithm which modified gain and variance is presented in this paper(so-called MGVEKF algorithm).Using this filter algorithm to filter about multiple measurements. Finally, using PFRC algorithm and MGVEKF algorithm to fixed target and moving target on the ground, simulation results are shown to verify the efficiency of the algorithms.