自适应递归型MTI滤波器的设计

为了克服横向动目标显示 (MTI)滤波器通带带宽窄、过渡带宽度宽、慢速目标检测性能差等缺点 ,提出一种自适应递归型 MTI滤波器的设计方法。设计中采用最大熵谱估计方法来实时、自适应地得到前向系数 ,利用遗传算法来提前设计反馈系数。实验仿真结果证明 ,这样设计出的 MTI滤波器不仅具有大的改善因子 ,而且还有通带平坦、通带带宽大、过渡带陡峭等优良特性 ,此外对于目标 ,特别是慢速目标的衰减可以小于 2 d B,因而对于目标检测非常有利。

Design of the adaptive recursive MTI filter

The normal transverse moving target indication (MTI) filter has many disadvantages, for example, the passband width is narrow, while the transition band width is wide. Therefore, this filter will be ineffective for detecting slow speed targets. In order to avoid these disadvantages, a method that can design the adaptive recursive MTI filter is presented. The forward coefficients of the filter can be adaptively determined using the maximum entropy method in real time. The feedback coefficients of the filter must be determined using the genetic algorithm in advance. Simulation results demonstrates that the recursive MTI filter has not only high improvement factor, but also such excellent characteristics as small passband ripple, wide passband width and steep transition band. In addition, the signal to noise ratio loss of targets, especially slow speed targets, is less than 2dB. As a result, the adaptive recursive MTI filter will benefit detection of weak or slow speed targets.