Space weather hazards: Monitoring and mitigation for GNSS

全球定位系统(GPS)等基于卫星的导航系统工作在超高频范围内，通常在1.1至1.6 GHz之间。这些L波段的信号容易受到电离层折射以及加拿大纬度电离层闪烁引起的快速随机相位和幅度变化的影响。大的定位误差与该区域电离层活动水平高有关，在闪烁事件期间观察到信号可获得性的损失，损害了对安全至关重要的导航系统(例如海洋导航或商业航空)的完整性和可靠性。未来几年将提供更多的全球定位系统信号和一个新的全球导航卫星系统--伽利略，预计2010年年中将达到太阳周期的顶峰。全球定位系统/全球导航卫星系统应用是一个价值数十亿美元的产业，需要为加拿大的全球导航卫星系统应用开发空间天气警告和警报。在这里提出的研究中，将对全球导航卫星系统的空间气象危害进行表征，并量化对各种导航应用的影响。将开发算法来实时监测重要的空间天气影响，包括闪烁。通过与加拿大地质调查局的伙伴关系，这项技术将被转让，以便在业务服务中实际实施。通过与工业界合作并使用最先进的全球导航卫星系统软件接收器，将调查和减轻电离层闪烁的影响。将开发强大的接收器跟踪环路，以提高全球导航卫星系统观测的可用性和可靠性。总体而言，加拿大的卫星导航系统的导航完整性将得到改善。

Satellite-based navigation systems such as the Global Positioning System (GPS) operate in the UHF range, which is typically between 1.1 and 1.6 GHz. These L-band signals are susceptible to ionospheric refraction and rapid random phase and amplitude variations due to ionospheric scintillations at Canadian latitudes. Large positioning errors are associated with high levels of ionospheric activity in this region, and losses of signal availability have been observed during scintillation events, with compromised integrity and reliability of safety-critical navigation systems (e.g. marine navigation or commercial aviation). Additional GPS signals and a new global navigation satellite system (GNSS), Galileo, will become available in the next several years, and a solar cycle peak is expected mid-2010. GPS/GNSS applications are a multi-billion dollar industry, and a need exists to develop space weather warnings and alerts for GNSS applications in Canada. In the research proposed here, space weather hazards for GNSS will be characterized and the impact quantified for various navigation applications. Algorithms will be developed to monitor space weather effects of significance, including scintillations, in real-time. Through partnership with the Geological Survey of Canada, this technology will be transferred for practical implementation in an operational service. By partnering with industry and using a state-of-the-art GNSS software receiver, the effects of ionospheric scintillation will be investigated and mitigated. Robust receiver tracking loops will be developed for improved availability and reliability of GNSS observations. Overall, it is intended that navigation integrity will be improved for satellite-based navigation systems in Canada.