臺灣博碩士論文加值系統

我國第一顆兼具太空科學.太空通訊與遙測等任務的衛星,中華衛星一
號(ROCSAT-1),預計在1998年底或1999年初升空o中華衛星一號將用Ka波段
的電磁波與地面站作通訊聯繫,其中上鏈為30GHz,下鏈為20GHz,當此種毫
米波在地球大氣通道中傳播時,由於受到大氣種種因素的影響,如氧和水汽
的吸收作用.雨滴的散射作用造成的訊號衰減與去極化現象.大氣亂流造成
的閃爍現象等,均使得毫米波發生異常的傳播現象o欲了解臺灣地區Ka波段
電磁波的傳播通道特性,首先要建立臺灣地區的大氣背景資料o本文利用中
央氣象局高解析度的降水資料來作不同緯度下的衰減量計算o

The ROCSAT-1 with the missions of space research, earth-
space communication and remote sensing is about to be launchedin
the end of 1998 or at the begin of 1999. By the specifica-tions
of the original desigins, the freqrncy for the earth-
earthcommunication of the ROCSAT-1 is ranged in the Ka band (
30GHz for uplink, 20 GHz for downlink). While millimeter
wavespropagate through the atmospheric chanel, the degradation
ofpropagation may take place, such as the attenuation and
thedepolarization by raindrops, the absorption by oxygen
andwater vapor, and the scintillation by atmospheric turbulance.
Taiwan, for the understanding of the propagation propertiesat Ka
band. In the whole context, the attenuation by rain iscalculated
under differert latitude through the analyzation ofrainy data
from Central Weather Bureau.