Wind Farms Clutters Suppression And Target Detection For LFM Air Surveillance Radar

The air traffic control radar,as an important part of air traffic control system,is a vital part of the flight safety system.Chirp pulse compression system is usually used in the air traffic control radar.The number of global wind farms increased rapidly in recent years,which might cause serious interference to the performance of air traffic control radar.The echoes of wind farm with continuous Doppler spectrum make the conventional clutter suppression method no longer applicable.Therefore,it is meaningful to study wind farm clutter suppression and target detection methods for linear frequency modulated(LFM)air traffic radars for improving target detection probability and reducing false alarm rate.Firstly,the theory of linear frequency modulated radar was introduced.The signal model of wind farm for LFM air traffic radar was established using the scattering point superposition theory,and was proved to be correct through the characteristic analysis in the frequency and time-frequency domain.Then the echo of air traffic radar was simulated,which provided data source and theoretical basis for the following research of clutter suppression and target detection.Secondly,a wind farm clutter suppression method for air traffic control radar based on spectral center compensation is presented.The matching pursuit method was also used to suppress wind farm clutter when the target was in the same unit with wind farm clutter,with the help of prior information such as the position of wind turbine and linear frequency modulation parameters.The target detection was then realized.The experimental results of simulated data and measured data show that this method can reduce the false alarm rate and increase target detection probability.Finally,a wind farm clutter suppression method for air traffic control radar based on clutter map is presented.The clutter map was formed with constant False-Alarm Rate(CFAR)detection method,according to the fixed position and Doppler spectrum broadening feature of wind turbine clutter.Target points caused by wind farm clutter were eliminated using the established clutter map while the real target points reserved.The experimental results of the measured data demonstrated that the false alarm caused by wind farm can be reduced effectively.The differences and applicable conditions of the two suppression methods above were given in the end.