Based On A Single Station Passive Positioning Technology

The passive location, which uses electromagnetic wave emitted by target, has proved its merits of self-hiding and far-distance detecting in modem electronic warfare (EW) and information warfare, and it has been the hotspot in the field of non-linear tracking and estimation. Unfortunately due to slow speed and low accuracy, the traditional single observer passive location is hard to meet the demand of tactics. It is urgent to improve the accuracy and shorten the time for location of single observer passive location. Consequently, this research project is proposed to how to improve the precision of locating and shorten the time for locating, and study content is presented in detail as follows:In chapter one, the present studies on single-observer passive are reviewedIn chapter two, the algorithms used in bearing-only passive locating are researched. Particle filtering, which is improved in this dissertation, is successfully introduced to passive locating. Compared to expand Kalman filtering (EKF) and Unscented Kalman filtering (UKF), this improved particle filtering can improve the precision of locating and shorten the locating time.In chapter three, bearing-only passive location is researched. The observerbility of system is discussed, thereby the conditions which the measurements should satisfy to improve the observerbility are researched Based on the conditions, a few improved algorithms are proposed.In chapter four, some key technology in phase difference locating is discussed. The reason for phase difference measurement ambiguity is analyzed. Then the possible resolving method based on the theorem of remainder (SunZi theorem) is put forward. When the condition of the theorem of remainder is not satisfied, the possible resolving way for ambiguity elimination is proposed too. Meanwhile, the way for acquiring change rate of the phase difference is studied. Wavelet is used to augment the SNR and Kalman filtering is introduced to acquire the change rate of phase difference. In chapter five, the possible problems, which should be overcome in practice engineering, are discussed. The resolving method for flying posture change of observer is proposed. The transformation of longitude, latitude and plane coordinates is researched too, and the linear insert algorithm is utilized to achieve synchronization of the measurements from observer and GPS.