Space weather hazards: Monitoring and mitigation for GNSS

诸如全球定位系统（GPS）之类的基于卫星的导航系统在UHF范围内操作，UHF范围通常在1.1和1.6 GHz之间。这些L波段信号易受电离层折射以及加拿大纬度电离层振荡引起的快速随机相位和振幅变化的影响。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用性丧失，安全关键型导航系统（例如海上导航或商业航空）的完整性和可靠性受损。今后几年内将有更多的全球定位系统信号和新的全球导航卫星系统伽利略，预计2010年年中将出现太阳活动周期高峰。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，加拿大需要为全球导航卫星系统应用开发空间气象预警和警报。在此处提议的研究中，将对全球导航卫星系统的空间气象危害进行定性，并对各种导航应用的影响进行量化。将开发算法，以实时监测空间气象的重大影响，包括平流层。通过与加拿大地质调查局的伙伴关系，将转让这一技术，以便在业务服务中实际实施。通过与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。将开发强有力的接收器跟踪环路，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，加拿大打算提高卫星导航系统的导航完整性。

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.