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The European Commission is exploring the possibility of improving the security of the SBAS service. SBAS data is currently trusted by end users, even if the navigation data (and signals) are not protected. The objective of the SPARC project is to identify a viable solution to authenticate the SBAS messages, when broadcast by the GEO satellites, possibly providing authentication also for the GNSS constellations augmented by SBAS. SPARC is a procurement launched by EC under the H2020 Framework Programme and it is technically managed by GSA.
Satellite based augmentation systems (SBAS) have been conceived to support safety of life operations in aviation by broadcasting GNSS differential corrections and integrity information. They are used mostly during precision approach. SBAS systems are regional systems, such as EGNOS in Europe and WAAS in the United States, among others. The increasing amount of radio frequency interference (RFI) and cyber-attacks to navigation systems is an emerging trend that can threaten receiver operation. The signal broadcast by the SBAS service can be subject to falsification. Since SBAS data is trusted by the user, erroneous data would affect the computation of the navigation solution, in a manner that is not detectable by the traditional techniques available for GNSS. This creates a risk for any SBAS user, including civil aviation and safety-critical applications. Authentication techniques can mitigate some of these threats. The purpose of the SPARC project is to identify a viable solution to authenticate SBAS data, when broadcast by the GEO satellites, possibly providing authentication also for the GNSS core constellations.
The project includes three iterations of the design with the following steps:
1. The analysis of the external requirements. The purpose of this analysis is to consider the information available from the different organizations and stakeholders defining the aviation operational needs and developing SBAS standards. This is a fundamental step to identify a solution meeting the operational needs and current status of the standardization process.
2. The analysis of the technical drivers. This activity aims at identifying which technical requirement drives the design of the authentication technique; these technical requirements must be compatible with the current state of the SBAS technologies, the SBAS standardization process and the aviation community requirements.
3. The definition of the authentication techniques. The consortium will design and test techniques for the authentication of the SBAS messages and possibly also GNSS navigation data and will determine their impact on the SBAS availability or continuity performance. The broadcast of authentication data is done through the SBAS satellite communication channels.
The project will explore the transmission of the authentication data exploiting existing data channel and also new data channels. The project includes the development of a Simulation Environment capable of generating the whole SBAS and GNSS navigation chain (including GPS and Galileo constellations). The Simulation Environment allows to test each authentication solution to assess the impact on the SBAS services. It can work faster that real time or real time modes to provide statistically meaningful results from synthetic and real data for the metrics of interest.
China recently launched a new pair of navigation satellites – Beidou- 3M21 (Beidou-50) and Beidou-3M22 (Beidou-51) from the Xichang Satellite Launch Center, Sichuan province. The satellites are using a bus that features a phased array antenna for navigation signals and a laser retroreflector, with a launch mass 1,014 kg. Spacecraft dimensions are noted to be 2.25 by 1.0 by 1.22 meters. Usually, the satellites reside in a 21,500 – 21,400 km nominal orbit at 55.5 degrees.
The satellites are equipped with lightweight hydrogen maser clocks, which will serve as a more stable precision frequency reference to make the satellite navigation system work more accurately. This was the sixth launch dedicated to the replenishment of the Beidou Navigation Satellite System in 2019. www.nasaspaceflight.com
Russia plans to launch into orbit a spherical glass satellite for measuring Earth’s gravity field by the end of December. The BLITS-M retroreflector satellite will be launched together with three Gonets-M communications satellites using the Rokot carrier rocket, scheduled to take off from the Plesetsk Cosmodrome on December 25.
The BLITS-M satellite is an improved version of the Russian BLITS (Ball Lens In The Space) satellite. It is a glass sphere designed to obtain satellite laser ranging (SLR) data related to geophysics, geodynamics, and relativity. It will also be used to increase the accuracy of the Russian GLONASS navigation system, calibrate various radio systems in orbit and help determine Earth’s rotation parameters and the precise characteristics of our planet’s gravitational field.
Russia launched the first BLITS (Ball Lens In The Space) retroreflector nanosatellite into orbit in 2009. The satellite, which consisted of two outer hemispheres made of glass and an inner glass ball lens, collided with one of the fragments of the Chinese Fengyun-1C meteorological satellite on January 2013. https://sputniknews.com
China promotes greater use of BeiDou GNSS in Central Asia
The Chinese government has started an initiative to promote greater use of its BeiDou GNSS in Central Asian countries for applications such as precision farming, transportation, and disaster relief and management. Agreements between China and Central Asian countries were signed at the China-Central Asia Cooperation Forum held in Nanning, China, on 20 October 2019. The agreements bolster research and application development of BeiDou GNSS throughout the region. https://spacewatch.global
Russia is planning to launch about 30 GLONASS-K2 satellites to overhaul its aging GLONASS navigation satellite constellation. Over the past five years, Russia has been launching no more than two navigation satellites annually. At the same time, the majority of the GLONASS satellites in orbit operate beyond the warranty period. As a result, the GLONASS network experienced multiple malfunctions in 2019 when only 21 devices remained operational, while a total of 24 global satellites were needed to ensure global signal coverage. The GLONASS navigation grouping currently consists of 27 satellites, including 23 operational, two in maintenance, one spare and one in flight test phase. www.urdupoint.com