雷达导引头跟踪低空目标仰角误差分析

雷达导引头跟踪低空飞行目标时,其仰角跟踪误差会受多径传播的严重干扰.一般的"小平面"方法计算漫反射时,采用均匀分割地形的方法,这种分割法在大擦地角,目标距离地面较低的情况下,误差较大,并且计算时间较长.提出了非均匀分割的改进的"小平面"法,分析了4条回波路径的影响.采用了闭环跟踪法计算仰角误差,并利用改进的"小平面"法计算电磁波在起伏地/海面上的漫反射,可以较为真实的模拟导引头在跟踪低空目标时的仰角跟踪误差,并可以大大缩短计算时间.

Analysis of elevation error for radar seeker tracking low altitude target

The elevation error of seeker tracking low altitude target was affected by multipath propagation. The traditional ‘little plane’,which calculates diffuse reflection coefficients, was used in uniform terrain meshing. But uniformterrain meshing has a high error rate in big grazing angle. An improved method which doesn't divide terrain uniformly and analyses effects of four paths propagation was proposed. The method of estimation elevation estimation commonly is open-loop track. A close-loop tracking method and improved method of‘little plane’which calculates diffuse reflection on ground/sea were presented. When the seeker track low altitude target, the elevation error was simulated better and calculation time was greatly reduced.