Citation
Abstract
Two uncertain factors affecting a telecommunication system’s performance are effective antenna gain and system noise temperature. For an Earth-geostationary satellite–Moon system, they are attributed to the atmospheric attenuation and radiation. In the super-high frequency band, the attenuations are mostly weather related and have the same values for both upward- and downward-propagating signals, while brightness temperatures have different effects for upward- and downwardlooking antennas. In this study, six link scenarios for this system are analyzed. Analysis of atmospheric attenuation and brightness temperatures for each link are presented. This study also discusses the general methodology for determining the noise temperature for a receiving antenna pointing to a blackbody of a given angular extent. A set of curves is presented that is independent of the sizes and brightness temperatures of black bodies. Antenna noise temperature increases are calculated as a function of distance between the antenna beam center and the blackbody disk center normalized by the disk radius. To show an example, these ratios are applied to a case of an Earth-based antenna looking toward the Moon.
Details
- Volume
- 42-168
- Published
- February 15, 2007
- Pages
- 1–22
- File Size
- 927.1 KB