由於臺灣處於颱風路徑上，因此颱風常對台灣造成災害，而目前我國各氣象單位能接收到只有GMS系列衛星的氣象資料。我們希望在每個小時之內，有衛星通過會受颱風影響的區域上空，以執行氣象觀測任務，提供詳細之颱風位置、大小、移動方向等氣象資料。 本文在根據任務需求，分析衛星之任務特性，決定了衛星軌道類型為高度為八百公里、傾角為98.6度的太陽同步軌道；並由地球、CCD與衛星之幾何關係，計算及決定真實水平面及有效水平面；透過衛星軌道與地面軌跡的計算，及衛星星系的假設分析，統計計算出不同衛星星系通過有效水平面之平均間隙及最大間隙，並比較其覆赫觸v。而根據模擬的結果，要符合任務需求所須最少的衛星數目為16個及最佳的衛星星系分佈為16/16/2的Walker衛星星系模式，各衛星升交點經度差為22.5度，而相臨軌道衛星間之幅角差為45度。 Taiwan is always on the pass way of typhoon, so typhoon always act natural disaster to Taiwan. Our weather station can only receive weather message from the GMS series satellite. We hope at least one satellite pass through Taiwan in an hour to execute weather observation mission, and provide more detail about typhoon. Based on the mission demand, we analysis the characteristics of mission, decide the orbit type is sun-synchronous orbit with orbit height is 800 km and orbit inclination is 98.6 deg. According to the calculation of orbit and orbit tracking, geometry between satellite and Earth, and assumption of several types of constellation, we can gather statistics of time of satellite pass through effective horizon. Then we can get the maximum gap and mean gap of different constellation, and analysis the efficiency of coverage. The final submission, we can use 16 satellites with 16/16/2 walker constellation to accomplish our mission.
