Research And Implementation Of Single Observer Passive Location And Tracking Algorithm

With the continuous development of electronic warfare and integrated reconnaissance and attack in modern electronic warfare,as a supplement and improvement of active detection system,passive location and tracking system is developing towards high precision,low load and fast locating.This paper focuses on the methods and basic principles of fast moving single observer passive location,location error analysis,direct position determination(DPD)based on array data and passive target tracking algorithm based on direction finding system.Then,we propose corresponding solutions to some existing problems,and verify the effectiveness of the proposed method through simulation experiments.Motion single-station passive location utilizes observation variables and data,which are acquired at different observation locations,to estimate the state of unknown emitters.At fact,it is essentially a complex non-linear filtering problem.Firstly,aiming at the problems of ambiguity in single-long baseline interferometer direction finding and complexity of multibaseline interferometer angle measuring and positioning system,a Single observer passive location for solving ambiguity phase difference in motion observation platform is proposed in this paper.Moreover,we derive the location error geometrical dilution of precision(GDOP)under phase difference,carrier frequency and observation station error.Then,we put forword the improved grey wolf optimization algorithm to estimate the location of emitter.The emitter position can be estimated by using the proposed algorithm,and multi-band emitter location can be achieved by single baseline interferometer only.Secondly,aiming at the shortcomings of traditional two-step positioning methods,such as information loss,measurement variable accuracy limiting the positioning accuracy,the DPD algorithm based on subspace data fusion of array antenna is studied,which improves passive location accuracy compared with the two-step location method.In addition,using the Doppler frequency shift generated by the relative motion between the fast moving single station and the emitter,the extended subspace data fusion DPD based on angle and Doppler frequency shift is further studied.The results show that the method can further improve the positioning accuracy under lower signal-to-noise ratio.In the practical application environment of single-station reconnaissance and location,there may be slow motion emitter,so it is necessary to estimate the position and velocity state of the emitter at the same time.The SRUKF algorithm based on the angle of arrival and the change rate of phase difference is studied.The rough estimation of the emitter position is realized by using the angle measured by the observation platform at different positions,and it is used as the initial value of the subsequent tracking.Then,the velocity of the emiter is gradually estimated based on the filtering model,which introduces the change rate of phase difference.The simulation results show that the tracking algorithm can estimate the position and velocity state of the emitter and further improve the estimation accuracy of emitter position.Finally,making use of the signal processing system based on the framework of FPGA and DSP,we study the realization of single-station passive location algorithm based on crossmean filtering of angle measurement on the platform of DSP.Through numerical simulation experiments and test of on-chip system locating algorithm,the results meet the requirements of locating indicators and complete the expected functions.