Degradation analysis of user terminal EIRP and G/T due to station-keeping variation of stratospheric platform

Wireless communication systems using airship have been proposed in worldwid e. The airship will be Located at the stratosphere about 20 similar to 23 k m above the sea level The position of airship will vary within the station keeping range with time due to the drag of the wind in the stratosphere. Wh en the earth station antenna has a high gain without the tracking function, the antenna performance may be degraded by a small variation of the airshi p. This means that variation of airship location could result in serious de gradation of the system performance. In this paper; degradation in earth st ation's Equivalent Isotropic Radiated Power (EIRP) and Gain to noise Temper ature ratio (G/T) due to the stratospheric platform movements has been deri ved by calculating the deviation angle of the main beam directions between the earth station and the platform antenna. In this case, the antenna of th e ear-th station has been assumed circular and/or patch array antennas.