Passive Radar Clutter Suppression Research, And Track Filtering Algorithm

The enduring survivability and the high working performance of radars are required by the modern high tech wars. Non-cooperative passive radar has been receiving increasing attention owning to the absorbing advantages, such as anti-jamming capability, anti-stealth ability and so on. Non-cooperative passive radar utilizes the signals emitted by FM broadcast station, TV station, etc. For the performance improvement and application of the non-cooperative passive radar, some key technologies need further study and development. In this dissertation, the clutter suppression and the tracking filter are discussed and analyzed.Direct signals, Ground clutter and Multi-path signals are the main influencing factors that affect the performance of the passive radar. An improved adaptive filtering algorithm for clutter cancellation is proposed in this paper. The algorithm, which combines frequency-domain adaptive filtering and variable step LMS algorithm, not only considerably reduces the computational complexity, but also improves the convergence rate and reduces the filtering error. The new algorithm, compared to the traditional LMS and RLS filter, is simulated for processing both theory data and radar received data. Simulations verify the feasibility and validity of the proposed algorithm.When using television signal, the range of target couldn't be measured accurately .To solve this problem, the Cartesian co-ordinate and velocity of the target are estimated by the way of the track filtering for Doppler frequency and direction of arrival. In order to avoid the filter divergence and improve the real-time property of the filter, an adaptive Sage-Husa filtering algorithm for manoeuvring targets tracking is developed. The measurement and process noise model will be changed and computed according to observation data and the information of dynamic system. Compared with traditional Extended Kalman filtering, the simulation results indicate that the new algorithm can correct the distribution problem, and improve the accuracy and stability of target track.