中文说明：
航管雷达的天线在水平方向上具有比较窄的波束，在垂直面上具有比较宽的波束，该程序仿真了航管雷达垂直面上余割型天线方向图。
English Description：
The antenna of ATC radar has a relatively narrow beam in the horizontal direction and a relatively wide beam in the vertical plane. This program simulates the cosecant antenna pattern on the vertical plane of ATC radar.