GNSS software receiver development and ultra-tight integration with inertial sensors

定位能力在当今社会变得司空见惯，某些汽车、移动电话甚至服装都配备了导航系统。大多数系统至少部分依赖于全球导航卫星系统(GNSS)技术，如美国全球定位系统(GPS)。使用最佳数据处理策略，定位精度可达2-3厘米。不幸的是，到达地球的GPS信号的功率非常低，这在历史上限制了它们的使用范围，在那里可以接收卫星信号，而不会受到树叶和建筑物等东西的衰减。然而，在过去的十年里，GPS接收器制造商已经开发出高灵敏度的接收器，可以在恶化的环境中跟踪信号，例如在室内，信号衰减约1000倍。尽管扩大了工作范围，但高灵敏度接收器的定位精度通常不超过几米。

Positioning capability is becoming commonplace in today's society with certain automobiles, mobile telephones and even clothing being equipped with navigation systems. Most systems rely, at least in part, on Global Navigation Satellite System (GNSS) technology such as the U.S. Global Positioning System (GPS). Using optimal data processing strategies, positioning accuracies can be as good as 2-3 cm. Unfortunately, the GPS signals that reach the Earth have very low power, which have historically limited their use to "open-sky" areas where the satellite signals can be received without being attenuated by such things as foliage and buildings. However, GPS receiver manufacturers have, in the past ten years, developed high-sensitivity receivers that can track signals in degraded environments such as indoors where the signal is attenuated by a factor of about 1,000. Despite this extended operational range, high-sensitivity receivers typically suffer from positioning accuracies no better than several metres.