The upper-limit of the positioning dilution of precision ( PDOP ) is an important index to design of a navigation constellation and evaluation of its performance. 定位精度因子(PDOP)上限取值是导航星座设计及其性能评价的基本依据。
During static positioning of satellites system, geometrical dilution of precision ( GDOP ) is usually used as an important index of evaluating satellites ′ combination. 在卫星系统的静态定位中,通常把几何精度因子GDOP的大小作为评价星座组合优劣的重要判据。