中文摘要：

当前，GPS／INS组合系统在精确定位，定向时被认为是最主要的传感器，并被应用在摄影测量，地图绘制或者其它方面．然而，该系统的可靠性和精度主要依赖于环境和其它条件，在城市范围特别是在卫星信号经常失锁的地方表现尤其明显。为了保持稳定性和可靠的精度，或者进一步提高这样系统的精度，本文介绍了地面卫星系统（又称伪卫星）．这种卫星改善了可用卫星的几何图形，从而保证并且提高了地面GPS／INS组合系统的可靠性和精度．

英文摘要：

Currently, GPS/INS integrated systems are considered the primary sensors to collect precise position and orientation data for photogrammetry, mapping, or other applications. However, the reliability and accuracy of such a system mainly depends on the environment and other conditions, especially for the land-based GPS/INS integrated systems operating in urban regions where losses of GPS lock occur frequently. In order to retain stable and reliable accuracy or even to improve the accuracy of such a system, ground-based satellites called pseudolites （PSL for short） are introduced in this paper to reinforce the geometry of the available satellites, thus to maintain or to improve the reliability and the accuracy of the land-based GPS/INS integrated systems.