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，並比較其覆蓋效率。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。 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 cons tellation, 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.
