降雨和大气分子环境对引信回波响应的影响

Impact of rainfall and atmospheric molecules on theecho response of fuzes

针对大气环境特性数据在引信工程设计中运用不足的问题,基于Monte-Carlo辐射传输模型和数字信号处理模型,提出了一种将大气环境特性数据应用于引信回波响应特性的仿真建模方法,利用ITU建立雨衰模型,验证了本文中的雨衰模型,研究了雨滴、水蒸气和氧气分子综合作用下对非大气窗口毫米波的衰减特性,并将毫米波的衰减特性数据应用于引信回波响应特性的仿真建模中,建立了引信回波响应模型,给出了引信回波响应特性中的一维距离像和距离-多普勒像,分析了暴雨和特大暴雨中引信目标回波功率和信噪比的变化规律。研究发现,中心频率60、118、184 GHz引信目标回波功率在暴雨中分别降低了2.5、1.8、2.9 dB,信噪比分别降低了1.2、0.9、1.3 dB。结果表明:即使是特大暴雨,空气中雨滴的散射与吸收作用对短距离引信目标回波并不能产生质的改变,但会降低目标回波的信噪比,使引信探测系统目标检测概率下降。从无雨到暴雨再到特大暴雨,中心频率60 GHz引信回波信噪比分别为15.7、14.4、12.9 dB,基于Neyman-Pearson准则,当引信探测系统虚警概率为10-7时,引信探测器的目标检测概率分别为0.999 7、0.986 9和0.852 1,结果显示,极端条件下的降雨颗粒和大气分子的衰减特性对引信的目标检测概率影响显著。文中降雨和大气分子对引信探测影响的建模方法可为引信工程设计中的环境适应性评估提供理论与方法支撑。

In response to the underutilization of atmospheric environmental characteristics characteristic data in fuze engineering design,a simulation modeling method that applies atmospheric environmental target characteristic data to the echo response characteristics of the fuze is proposed based on the Monte-Carlo radiative transfer model and digital signal processing model.The rain attenuation model in this study was validated with the ITU recommended rain attenuation model.The attenuation characteristics of non-atmospheric window millimeter waves under the combined effects of raindrops,water vapor,and oxygen molecules are investigated,in which the attenuation characteristics data are applied to the echo response characteristics of the fuze in simulation modeling.A fuze echo response model is established,presenting the one-dimensional distance image and range-Doppler image in the fuze echo response characteristics.The variations in the echo power and signal-to-noise ratio(SNR)of the fuze target in heavy rain and extreme heavy rain are analyzed,in which found that the echo power of fuze targets at center frequencies of 60 GHz,118 GHz,and 184 GHz decreased by 2.5 dB,1.8 dB,and 2.9 dB,respectively,and in heavy rain and the SNR decreased by 1.2 dB,0.9 dB,and 1.3 dB,respectively.Results indicate that even in extreme heavy rain,the scattering and absorption of raindrops in the air do not qualitatively change the short-range fuze target echo.However,they do reduce the SNR of the target echo,leading to a decrease in the probability of target detection by the fuze detection system.From no rain to heavy rain to extreme heavy rain,the SNR of the 60 GHz fuze echo is 15.7 dB,14.4 dB,and 12.9 dB respectively.Based on the Neyman-Pearson criterion,when the false alarm rate of the fuze detection system is 10-7,the target detection probabilities are 0.9997,0.9869,and 0.8521 respectively.The results show that the attenuation characteristics of rain particles and atmospheric molecules under extreme conditions significantly affect the target detection probability of the fuze.The modeling method for the effects of rain and atmospheric molecules on fuze detection can provide technical support for environmental adaptability assessment in fuze engineering design.