区域导航性能是评价星座导航能力的重要参数,从几何精度衰减因子(GDOP)出发提出了评价区域导航性能的指标:区域几何精度衰减因子标准差和区域几何精度衰减因子变化度。它们和区域平均几何精度衰减因子一起从不同的角度反映了星座的区域导航性能。针对不同的应用,可根据对应的指标确定区域导航的关键星。文中以Walker星座为例论述了依据这些指标选取星座导航关键星的方法。三个指标之间的相关性保证了大多数情况下关键星选取的一致性。
Area navigation capacity is an important parameter for evaluating navigation performance of constellation. The evaluation indexes of area navigation capability were presented, including standard deviation of geometry dilute of precision and variability of geometry dilute of precision from geometry dilute of precision, and the key-satellite of the navigation constellation was analyzed based on the indexes. The two indexes and area average geometry dilute of precision describe the area navigation capability in different ways.The indexes can fulfill different applications for determining the key-satellite of constellation for area navigation. The correlations between these indexes insure that the key-satellite is the same one in most cases.