Space weather disruptions to satellite navigation and telecommunications: ionospheric scintillation

现代世界越来越依赖于利用全球导航卫星系统（GNSS）的系统，其中最广为人知的可能是GPS。其中包括汽车或手机上的“卫星导航系统”。然而，除了用于运输（公路、航空、铁路和海上）之外，全球导航卫星系统还广泛用于其他应用，包括测量、应急服务、农业、移动通信和金融交易。2011年，欧盟委员会向欧洲议会和理事会提交的一份报告估计，当时欧盟有8000亿欧元的国内生产总值（GDP）依赖于卫星无线电导航。同年，英国皇家工程院的一份报告建议，直接或间接依赖GNSS进行定位、导航或授时（PNT）的服务“应将其记录为其服务描述的一部分，并解释其GNSS中断的应急计划”。我们将向我们的合作伙伴提供由电离层闪烁引起的此类中断风险的全球地图，电离层闪烁是影响电离层的空间天气的主要结果。闪烁是指来自GNSS卫星的无线电信号发生如此迅速的变化，以至于接收器无法“锁定”信号，因此无法使用该信号进行导航或定时。闪烁在高纬度和低纬度地区都很常见，但有时会延伸到英国、欧洲和美国等中纬度地区。例如，在2003年10月的“万圣节”太阳风暴期间，美国联邦航空管理局用于空中导航的广域增强系统（WAAS）网络被禁用了30个小时，主要是由于闪烁。我们的工作是及时的，因为GNSS的使用是如此普遍，以至于最近（2017年6月）创新英国报告估计，仅在英国，通过直接损失和连锁延误造成的GNSS五天中断的影响将超过50亿英镑。其中1.1亿英镑用于铁路部门，这是我们的项目合作伙伴特别感兴趣的领域。https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/619544/17.3254_Economic_impact_to_UK_of_a_disruption_to_GNSS_-_Full_Report.pdfhttp://lasp.colorado.edu/home/wp-content/uploads/2011/07/lowres-Severe-Space-Weather-FINAL.pdfhttp://www.raeng.org.uk/publications/reports/global-navigation-space-systems

The modern world is increasing reliant on systems that make use of Global Navigation Satellite Systems (GNSS), perhaps the most well know of which is GPS. These include the 'Satnav' in cars or mobile phones. However, in addition to its use in transport (road, air, rail and maritime), GNSS is used a wide range of other applications including surveying, emergency services, agriculture, mobile communications and financial transactions. In a 2011 report from the Commission to the European Parliament and the Council it was estimated that 800 billion euro of gross domestic product (GDP) in the European Union, was then dependent on satellite radio navigation. A Royal Academy of Engineering report of the same year suggested that Services that depend on GNSS for positioning, navigation or timing (PNT), either directly or indirectly, "should document this as part of their service descriptions and explain their contingency plans for GNSS outages". We will provide, to our partners, global maps of risk of such outages, caused by ionospheric scintillation, a major result of space-weather affecting the ionosphere. Scintillation is where there are such rapid changes in the radio signal from a GNSS satellite that a receiver cannot 'lock on' to the signal and so cannot use this signal for navigation or timing. Scintillation is common at both high and low latitudes, but can on occasions extend to middle latitudes such as the UK, Europe and the United States. For example, during the 'Halloween' solar storm in October 2003, the United States Federal Aviation Administration Wide-Area Augmentation System (WAAS) network for air navigation was disabled for 30 hours, primarily due to scintillation. Our work is timely as the use of GNSS is so ubiquitous that a recent (June 2017) Innovate UK report estimated that the impact in the UK alone to a five-day disruption to GNSS would be in excess of £5 billion through direct losses and knock-on delays caused. £110 million of this was in the rail sector, an area of particular interest to our project partners. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/619544/17.3254_Economic_impact_to_UK_of_a_disruption_to_GNSS_-_Full_Report.pdfhttp://lasp.colorado.edu/home/wp-content/uploads/2011/07/lowres-Severe-Space-Weather-FINAL.pdfhttp://www.raeng.org.uk/publications/reports/global-navigation-space-systems