Radome effect on the radar homing system

雷达制导系统中的天线罩如果不适当控制其厚度，会导致脱靶量增加甚至系统不稳定。本文以作者在杂波效应分析等方面所采用的系统框图为基础，采用非线性协方差分析方法对这些影响进行了分析。首先在方框图中引入天线罩效应，分析系统的稳定性，然后引入状态方程和协方差方程。分别对飞行过程中天线罩误差斜率不变的情况和时变情况进行了仿真。给出了不同参数变化时雷达罩误差斜率与脱靶量的关系，阐明了雷达罩误差斜率阶梯式和正弦式变化对脱靶量的影响。在1996财政年度，导弹被当作5阶滞后系统处理。稳定性分析表明，五阶模型不仅对天线罩误差斜率的负值引入了不稳定性，而且对正值也引入了不稳定性。状态方程和协方差方程，从而使程序适应于五阶模型。与三阶模型相同的标称值给出了严重的结果：大约是脱靶距离的两倍，以及上述的不稳定性。参数研究在三阶模型中进行。对天线罩的影响，特别是对时间变化的影响，我们只是零碎地了解，但通过这次调查，我们几乎完全分析了这种影响。

The radome in radar homing system makes the miss distance increase or even the system unstable unless its thickness is properly controlled. This report analyzes these effects by using a nonlinear covariance analysis method, based on the system block diagram the authors hitherto adopted in the clutter effect analysis etc.In FY 1995, the missile was handled as a third order lag system. First, the author introduced the radome effect into the block diagram, analyzed the system stability, then introduced the state and covariance equations. Simulations were performed for the case of the radome error slope being constant during the flight, and for the case of time-changing. The relations of radome error slope vs. miss distance are shown for various parameter changes in the former, the effect of stepped and sinusoidal changes of the radome error slope are clarifed in the latter.In FY 1996, the missile was handled as a 5th order lag system. The stability analysis indicated that the 5th order model introduces instability not only for minus values of the radome error slope but also for plus values. The state and covariance equations, and hence the programs were accommodated to the 5th order model. The same nominal values as the 3rd ordor model gave severe results : approximately twice of the miss distance, and the instability described above. Parameter studies were performed as done in the 3rd order model.The effect of a radome, especially that of time changing, which was known only fragmentary was ahnost fully analyzed through this investigation.