【摘要】 在空间时代，沿射线路径的总折射率是研究电波传播的重要参数。常规射电天文技术可监测此参数。基于不同类型射电望远镜和信号起伏，简述了从观测数据中提取传播媒质信息的方法。总结了这种监测方法的特点、与其有关的基础知识、提取媒质信息的要点和存在的问题。更多还原

【Abstract】 The total refractivity content along the ray path is an important propagation parameter in space times.From the points of view on the different types of radio telescopes, and on the signal fluctuation, a brief review about the methods for extracting the total refractivity content from conventional radio astronomical observation have been presented.The characteristics of various methods mentioned above, the basic related knowledges and the problems un solved are also indicated.更多还原