China to Join Effort on Aircraft Satnav Standards

EGNOS is Europe’s first venture into satellite navigation. EGNOS broadcasts augmented information through a trio of geostationary satellites linked to a network of monitoring ground stations, to sharpen the accuracy and reliability of GPS signals across the continent. Photo: EGNOS

Europe’s EGNOS augmentation system sharpens the accuracy and reliability of GPS signals so they can safely be used for landing approaches across a growing number of European airports. But aviation is a global enterprise — so the aim is to develop a seamless network of augmentation systems in future.

That is the task of an international group of experts, the Satellite Based Augmentation Systems (SBAS) Interoperability Working Group (IWG), whose 27th  meeting took place in Tampa, Florida, September 8-10, hosted by the Institute of Navigation.

Satellite augmentation systems combine dedicated ground stations and satellite transponders to sharpen satnav accuracy and provide integrity data — providing continuously updated reliability levels — across given geographical regions. These systems are based on GPS for now, but plans are to move to a multi-constellation design in the post-2020 era, making use of Europe’s Galileo, China’s Beidou and Russia’s GLONASS systems as well.

SBAS providers from around the globe gathered at Tampa, Florida, for the latest meeting of the SBAS Interoperability Working Group September 8-10. IWG 27 was hosted by the Institute of Navigation. Photo: SBAS

SBAS systems enhance any type of location-based satnav use, but in practice, aviation is the main driver. The ESA-developed European Geostationary Navigation Overlay Service, EGNOS, commenced its general-public Open Service in 2009, with the Safety-of-Life Service for aircraft vertical landing approaches following in 2011.

For next-generation SBAS systems, the IWG is designing a multi-constellation and dual-frequency standard for heightened accuracy and reliability, building up to offering SBAS coverage on a worldwide basis.

Didier Flament, representing ESA — which co-chaired this IWG meeting with the U.S. Federal Aviation Authority — commented: “Among the achievements of the Tampa IWG has been the presentation of an ongoing review of a standard message definition for the new and second SBAS channel — known as L5 — of the second-generation SBAS system, to be used along with the current L1 signal.

The meeting also introduced two new SBAS development projects, adding to the five existing projects presented at IWG 26. The first was presented by the Agency for Air Navigation Safety in western Africa and Madagascar (ASECNA), a public international organization with 18 member states.

China’s BeiDou SBAS development plan, presented at IWG 27 in September 2014.

ASECNA’s project aims to take a two-step approach, commencing with EGNOS-style vertical landing guidance for selected airports, based on EGNOS constituents, with a tentative schedule of 2018, moving to upgrade to the dual-frequency multi-constellation service across the whole of ASECNA airspace after 2020.

The second new project is China’s own BeiDou SBAS. After discussions at ICAO level, China has committed to delivering SBAS services over China that are fully compliant with ICAO standards.

“This new plan has been highly welcomed by the aviation community and other SBAS providers,” Didier said. “Chinese representatives have also confirmed their intention to become part of the SBAS IWG and contribute to the work done to finalise the future standard.”

The follow-up IWG meeting will take place in February 2015 and will be hosted by ASECNA in Dakar, Senegal.

About EGNOS

EGNOS, the European Geostationary Navigation Overlay Service, is Europe’s first venture into satellite navigation. Its development was managed by the European Space Agency (ESA) under a tripartite agreement with the European Commission (EC) and the European Organization for the Safety of Air Navigation (Eurocontrol).

The ownership of the EGNOS assets was transferred from ESA to the EC in April 2009 and EGNOS officially entered service on October 1, 2009. The service is delivered, through a contract with the European GNSS Service Agency (GSA), by the European Satellite Services Provider, ESSP SaS, founded by seven air navigation service providers. ESA is the design and procurement agent for EGNOS on behalf of the EC.