基于波瓣分裂的米波雷达低仰角测高方法及其应用

Method of Altitude Measurement Based on Beam Split in VHF Radar and Its Application

针对米波雷达的波束较宽、由于地面反射引起波瓣分裂,通常只能估高而不能测高这一难题,提出一种基于分裂波瓣的米波雷达低仰角测高方法——比相比幅法.该方法采用多个不同高度的测高天线,由于不同高度天线的分裂波瓣有一定的相位关系,利用该相位关系确定目标所在仰角区间;利用不同天线接收信号幅度进行比幅处理提取归一化误差信号;再查表得到目标的高度.分析地面起伏对测高精度的影响;推导不同阵地情况下的比幅误差曲线.将该方法应用于某型雷达,在我国首次成功地进行了米波雷达测高.试验结果表明该方法是行之有效的.

The altitude of a target can only be estimated roughly by very high frequency（VHF） radar for this kind of radar has a wide beam which is usually be split because of the reflection from the ground. To resolve this problem, the paper proposes an accurate and effective method for measuring the altitude based on beam split,namely,Phase-comparison and Amplitude-comparison. In this measuring system, several antennas of different heights are utilized. Owing to the certain relationship among the phases of the split beams of different antennas,the phases of the echoes can be used to determine the elevation region the targets locate. Using ＂Amplitude-comparison＂ of echoes from various antennas to pick up the normalized error signals,the elevation of the target is obtained through looking up the table. An analysis of the effect on the altitude measurement accuracy caused＇by the roughness of ground is presented. This method has been used in some radar, and has been successfully used in the experiment of the altitude measurement in VHF radar. It has been proved that this approach is effective to measure the altitude of a target which has a rather low elevation.