Space weather disruptions to satellite navigation and telecommunications: ionospheric scintillation

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.pdf

http://lasp.colorado.edu/home/wp-content/uploads/2011/07/lowres-Severe-Space-Weather-FINAL.pdf

http://www.raeng.org.uk/publications/reports/global-navigation-space-systems

The objective of this project is to transfer knowledge to industrial partners on the likelihood and severity of disruptions introduced by scintillation during adverse space weather conditions on infrastructure relying upon satellite telecommunications and navigation over a global scale as well as on the systems interdependencies.

This project will provide advice on possible mitigation strategies and countermeasures in accordance with risk maps that can contribute to contingency plans. For example, technical specifications of minimum requirements of radio receivers, best practice to operate radio receivers, optimal methods to minimise accuracy degradation on precise point positioning and differential positioning.

Through the knowledge gained from this project, the project partners will be able to: (a) assess risks for industrial operations and services vulnerable to ionospheric scintillation; (b) inform their clients and decision-makers on best practices to minimise risks; (c) effectively and successfully manage emergency crises; (e) improve their short and long-term investment decisions, minimising costs arising from services outages introduced by scintillation associated with adverse space weather.