Detection Of Low-altitude Windshear With Airborne Weather Radar Based On STAP

Low-altitude windshear, with the characteristics of small scale, high intensity and difficult to detect, is now a serious safety hazard to aircraft in takeoff or landing phase. Airborne weather radar is the important equipment installed in aircraft for sensing the meteorological information, when the radar works in looking-forward mode for low-altitude windshear detection, the useful signal is general covered with ground clutter which results in the difficulty of windshear detection. Research shows that phased array antenna, with the characteristics of flexibly, high scanning speed and easy to beamform, is now an important development direction of modern radar. The next generation of airborne weather radar intends to utilize phased array system so as to gain an advantage of ground clutter suppression, and detect dangerous weather information in strong ground clutter background. According to the airborne weather radar in phased array system, research on detection of low-altitude windshear based on STAP is now an important topic in aviation safety.Firstly, the geometric model of airborne forward-looking array and the space-time clutter model are introduced. On the basis of low-altitude windshear modeling approach, the space-time signal model of low-altitude windshear is researched. Low-altitude windshear signal and ground clutter of airborne forward-looking array are simulated and analyzed.Secondly, the traditional windshear detection process is introduced and traditional methods of wind speed and gradient estimation are discussed and analyzed.Thirdly, according to airborne weather radar in phased array system, a new method of low-altitude windshear speed estimation based on generalized CAPON is proposed. Combined with the spectral distribution characteristics of low-altitude windshear signal, space-time adaptive processor based on generalized CAPON is constructed to suppress clutter and get the accurate estimation of wind speed.Finally, a new method of low-altitude windshear speed estimation based on ??-STAP is proposed on the basis of the generalized CAPON algorithm, which results in the reduction of computational complexity of algorithm mentioned above. Paper utilizes ??-STAP theory into wind speed estimation and shows the effectiveness of the proposed method with simulation.