一、前言 1986年10月我国开办了卫星电视教育节目,这是促进我国教育事业快速发展的重要决策。我国地域辽阔,地形复杂,山脉纵横,利用广播电视卫星这种先进的信息传输工具是解决我国电视覆盖的经济有效的方法。卫星电视广播系统和地面电视广播系统相比较,具有下列优点: 1.电波覆盖面积大,利用效率高。由于卫星距地面赤道的垂直高度达3.6万公里,星体转发器用定向天线把电波聚集成窄波束,能比较均匀地辐射到覆盖区内,像我国 I. Introduction In October 1986, China started the satellite television education program, which is an important decision to promote the rapid development of China’s education. China’s vast territory, complex terrain, vertical and horizontal mountains, the use of radio and television satellites such advanced information transmission tool is to solve China’s television coverage of the economic and effective method. Compared with the terrestrial television broadcasting system, the satellite television broadcasting system has the following advantages: 1. The radio wave covers a large area and has high utilization efficiency. As the vertical altitude of satellite from the ground equator reaches 36,000 km, the celestial body transponder uses the directional antenna to gather the radio waves into narrow beams and radiates to the coverage area more evenly, like our country