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从介绍我国中央电视台租用Intelsat V卫星的情况着手,讨论如何改进卫星电视地面接收站的性能、改善卫星传输链路的图像信杂比和提高电视图像的质量等级等问题.地面接收站性能的高低由品质因素G/T值的大小来衡量,因此应尽量增加天线有效增益G和降低接收机等效噪声温度T.图像信杂比是影响电视全程图像质量的重要因素,它与星体转发器的全向有效辐射功率、传输路径损耗、附加损耗、G/T值、调频改善因子和去加重改善等有关.电视图像的质量等级共有五级.最后列出了G/T值与图像质量等级的计算例子.
This paper starts with the introduction of China Central Television’s rented Intelsat V satellite and discusses how to improve the performance of satellite terrestrial receiving stations, improve the signal to noise ratio of the satellite transmission links and improve the quality level of television images, etc. The performance of terrestrial receiving stations The quality factor G / T value to measure the size, so should try to increase the effective antenna gain G and reduce the receiver equivalent noise temperature T. Image to noise ratio is an important factor affecting the entire image quality of the television, it is with the transponder The total effective radiated power, transmission path loss, additional loss, G / T value, FM improvement factor and de-emphasis improvement, etc. There are five levels of quality of the television images.Finally, the G / T value and image quality level Calculate examples.