摘要
近年来,Ku和Ka卫星在广播、通信和军事等领域应用数量越来越多,传统的Ku和Ka波段星地链路降水衰减预报模型基于经验关系和理想假设,考虑降水微物理特性不足,针对此问题,在实测降水粒子微物理特征的基础上定量分析了降水垂直分布、粒子形状、粒子取向、粒子相态等对Ku和Ka频段信号衰减的影响特性.结果表明,与考虑降水非均匀垂直分布的计算结果相比,ITU和SAM模型是基于降水分布均匀的假设,无法代表降水垂直分布不均匀时的衰减情况;降水粒子形状和取向对衰减的影响较小,在13GHz和32GHz频段,球形和非球形粒子衰减值的平均绝对偏差均在0.01dB以下,不同粒子取向时衰减系数的平均绝对偏差最大值为0.00098dB/km和0.0207dB/km;不同相态的降水引起的衰减差异较大,衰减值从大到小依次是湿雪、水和冰.研究结果可以为Ku和Ka波段星地链路传播特性评估及降雨反演新方法提供基本的理论支撑和数据参考.
In recent years,the number of satellites with Ku and Ka band has been increasing in the fields of broadcasting,communication and military.However,traditional prediction models of rain attenuation for earth-space links in Ku and Ka band are based on empirical relationships and ideal assumptions,which consider insufficient precipitation microphysical properties.Aiming at this problem,the effect of vertical distribution of precipitation,particle shape,particle orientation and phase on signal attenuation are quantitatively analyzed based on measured rainfall data.The results show that compared with the calculation results of nonuniform vertical structure of rainfall,ITU and SAM models are based on uniform precipitation distribution,which cannot represent the attenuation when the vertical rainfall is nonuniform.The particle shape and orientation affect the attenuation for a slight degree,the mean absolute error of attenuation from spherical and non-spherical raindrops are below 0.01dB at 13 GHz and 32 GHz,and the maximum mean absolute error of specific attenuation for different particle orientations is 0.00098dB/km and 0.0207dB/km.There are different attenuation caused by precipitation with different phases,the values in descending order is wetsnow,water and ice.These results will provide basic theoretical support and data reference for evaluation of propagation characteristics and estimation of rainfall by earth-space links at Ku and Ka band.
作者
咸明皓
刘西川
姬文明
蒲康
胡帅
高太长
XIAN Ming-hao;LIU Xi-chuan;JI Wen-ming;PU Kang;HU Shuai;GAO Tai-chang(College of Meteorology and Oceanography,National University of Defense Technology,Nanjing,Jiangsu 211101,China)
出处
《电子学报》
EI
CAS
CSCD
北大核心
2020年第3期417-425,共9页
Acta Electronica Sinica
基金
国家自然科学基金(No.41505135,No.41475020,No.41975030)。
关键词
星地链路
Ku/Ka频段
降水
衰减
earth-space link
Ku and Ka band
precipitation
attenuation
作者简介
咸明皓,男,1995年11月出生,山东临沂人.2018年在国防科技大学获得工学学士学位.现为国防科技大学气象海洋学院硕士研究生,主要从事大气物理与大气探测方面的研究工作.E-mail:xmh199951124@gmail.com;通信作者:刘西川,男,1985年12月出生,河北清河人.2007年、2010年和2014年分别在解放军理工大学获得工学学士、理学硕士和理学博士学位.现为国防科技大学气象海洋学院讲师,硕士生导师,主要从事大气探测与大气遥感方面的研究工作.E-mail:liuxc85@gmail.com。
