One Galileo satellite has been reconfigured to emit a new signal component optimized to serve low-end receiver devices and internet of things (IoT) applications. According to the European Space Agency (ESA), GSAT0202, in elliptical orbit, was reconfigured in January to transmit the new signal, also known as the G1 E5 Quasi Pilot.
The G1 E5 Quasi Pilot in the E5 band lies along a narrow part of the overall Galileo signal, intended to enable streamlined positioning fixes requiring less calculation — without affecting the E1 and E6 signal bands, on which Galileo also transmits. The initial receiver test showed that the signal component has the potential to reduce the signal acquisition time by a factor of three compared to the current GPS L5 or Galileo E5a signals.
Image: ESA
Once GSAT0202 was reconfigured, signal measurements were collected using the high-gain antenna installations from the Galileo in-orbit test facility, which confirmed the stability of the augmented signal. After G1 E5 Quasi Pilot was broadcast, it was successfully acquired and tracked by a set of receivers.
Airbus Defense and Space, Thales Alenia Space Italy, the European Union Agency for the Space Programme (EUSPA), the European Commission, and Spaceopal supported this test.
The other elliptical Galileo satellite, GSAT0201, will also be reconfigured after further testing. Selected chipset manufacturers will be involved in the testing under supervision of EUSPA. The test results will be evaluated at the Galileo Programme level, to eventually introduce G1 E5 Quasi Pilot into the constellation.
In 2022, the Galileo GNSS continued to provide the world’s most precise satellite navigation information, to a user base that stands at more than 3.5 billion worldwide. Furthermore, provided services continue to improve and expand, with plans for high-accuracy positioning and signal authentication now reaching fruition.
The European Union Agency for the Space Programme (EUSPA) and the European Space Agency (ESA) continue to enjoy an effective collaboration on the many development, deployment, and evolution activities of the Galileo Programme — each according to their respective responsibilities for service provision and system development with the European Commission (EC) acting as the program manager.
Ranging accuracy performance from January to September 2022.Positioning-related MPLS from January to October 2022.
New Services Launched in 2022
Excellent Performance
Service delivery operations and maintenance of operational systems are managed by EUSPA, which supervises many contracts that carry out the day-to-day activities from dedicated control and monitoring centers throughout Europe. In 2022, Galileo timing, navigation, and SAR/Galileo services were delivered with excellent performances that continue to exceed the formal declarations for minimum performance levels (MPL), which were increased in January, both in terms of absolute accuracy and overall service availability. The entry into service of two additional satellites in May and August, have further consolidated the overall service availability to end users.
Galileo FOC Batch 3 satellite under testing.
Expansion of Service Portfolio
The service provision teams have been able to focus on improvements to, and expansion of, the service portfolio.
The I/NAV improvement will positively impact end users by enabling a faster time to first fix, and updates to the data validity status flags will lead to better protection of users against expired navigation data. These changes are implemented in updates of the onboard software of the satellites being rolled out across the constellation. At present, seven operational satellites have been successfully updated; the complete software upgrade campaign is planned to be completed this summer.
Galileo’s new High Accuracy Service will provide free precise point positioning (PPP) corrections, in the Galileo E6-B data component and by terrestrial means, for Galileo and GPS (single and multi-frequency) to achieve real-time user position improved by up to 10 times. The infrastructure to support an initial service (Phase 1) is nearing completion, and the formal declaration of the service capabilities is planned for early this year.
To provide users with a method of authenticating the received Galileo signals, especially the satellites ephemerides and the Galileo timing parameters, the new Open ServiceNavigation Message Authentication (OSNMA) service enables a receiver to confirm that a navigation message originated from the EU Galileo infrastructure. Many application areas are expected to benefit from this capability, including smart tachographs, telematics and logistics, UAVs, location-based services, and timing services. Having successfully demonstrated the technology behind the service in 2022, including a public observation phase, the roll-out of the Initial Service is planned to take place by the end of the year.
A fourth Medium Earth Orbit Local User Terminal (MEOLUT) in La Réunion will extend the SAR/Galileo Forward Link Service Coverage Area over the Indian Ocean as part of the SAR/Galileo full operational capability (FOC) declaration expected in the first quarter of 2023. The Cospas-Sarsat commissioning of this new station was completed in September 2022, and operational data is already being distributed to Cospas-Sarsat.
Reference documents for the above services can be found at the EUSPA European GNSS Service Centre website, including technical notes, interface control documents and service declaration documents.
SAR/Galileo-related metrics from January to October 2022.Extension of the SAR/Galileo Forward Link Service Coverage Area over the Indian Ocean.
FOC Infrastructure Development Nears Completion
Satellite Production
The production of the third batch of Galileo FOC satellites advanced further in 2022 with the completion of the environmental tests and the system compatibility test campaigns at the European Space Agency Test Centre in Noordwijk, The Netherlands. After 10 years of successful testing, on Oct.18, 2022, the last Galileo FOC satellite (flight model number 34) left the test center to return to the premises of the satellite manufacturer, OHB Systems, in Germany. Testing of the remaining 10 satellites has confirmed that they have been correctly built and will perform well in orbit. The acceptance review of the last couple of satellites will take place this summer.
At the beginning of 2023, the plan is to start in-orbit testing of a quasi-pilot signal on the E5 frequency using the Galileo GSAT201/202 satellites in elliptical orbit. The provision of a signal offering coarse acquisition in Galileo E5-A/GPS L5 can be a distinguishing feature for Galileo with respect to all other constellations to further improve the capability to acquire the E5 signal at low complexity. Following in-orbit testing, the strategy for roll-out of this capability will be assessed with the involvement of receiver manufacturers.
New SAR Galileo MEOLUT facility in Réunion island.
Access to Space
The discontinuation of Soyuz launch services from the Kourou Space Centre in French Guiana, because of the Russia-Ukraine conflict, has caused delays in the two Galileo launches that had been planned for 2022. The Launch 12 campaign had to be interrupted and in March 2022 the FM25 and 26 satellites were put in storage at the Kourou launch base, then returned to Europe in November.
Ariane 6 is the baseline launcher for Galileo satellites to ensure European independent access to space. The remaining Batch 3 satellites will be launched with the Ariane 62 launcher vehicle, the two strap-on solid booster variants of Ariane 6, now undergoing the final stages of development led by prime contractor Ariane Group. Ariane 6’s maiden flight is scheduled to take place in the fourth quarter of 2023.
Ground Segment
An upgrade of the ground control segment, in charge of command and control of the satellite constellation, is being developed by the industrial consortium led by GMV. The upgrades will address resolution of hardware and software obsolescence including cyber security, operability improvements, and a security monitoring overlay.
With the planned increase in the number of satellites in orbit, an additional telemetry tracking and control facility (TTCF) is being deployed in Kourou leading to seven operational TTCF stations in early 2023.
The ground mission segment, in charge of navigation control, is undergoing a complete technological refresh, including hardware/software virtualization performed by an industrial consortium led by Thales France. This upgrade will provide additional robustness, including a system extended contingency mode resilient to outages lasting up to seven days and a new state-of-the-art cyber security monitoring system. It will also provide ranging authentication through encrypted codes on the E6-C signal component for the implementation of the Commercial Authentication Service. Global coverage will be further increased with the introduction of two Galileo sensor stations in Wallis (Pacific Ocean) and Bonaire (Caribbean Sea), for a total of 15 sites around the globe.
OSNMA-related metrics from January to October 2022.
G2G Development Started
Galileo’s second generation (G2G) will introduce many innovative technologies to offer unprecedented precision, robustness, and flexibility.
2022 was a key year for the evolution of G2G activities with the fast development cycles of the first batch of G2 satellites, beginning development of the associated G2G in orbit validation (IOV) ground segment and system test beds, and the consolidation of the G2G final system capabilities — including the coordination of the mission/service roadmaps with the EC, EUSPA, and the EU Member States delegates.
Ariane 62 launcher.
G2G Satellite Manufacturing
From the satellite development point of view, the two parallel contracts to develop and manufacture each of the six G2G batch one (G2SB1) satellites are progressing in a fast development environment, with the first hardware units ready for integration and testing.
Following the completion of preliminary design review, these two contracts (for six satellites each) are preparing for unit-level validation/testing, which will lead to the critical design review.
These satellites will provide the following key innovations:
Reconfigurable fully digital navigation payload
Point-to-point connection between satellites by inter-satellite-link for command and control, and ranging functionalities
Electric propulsion for orbit-raising capabilities
Advanced jamming and spoofing protection mechanisms to safeguard.
The Galileo signals will improve with:
On-board authentication capabilities
Increased ground-to-space data rate
Improved time reference (number of clocks and advanced clock monitoring functions).
G2G IOV Procurements
2022 was also the year in which two key events took place with respect to G2G in-orbit validation (IOV) ground segment and system test bed procurements:
Finalization of the procurement cycle, now in the final evaluation/award phase, to be kicked off in the first quarter of this year
Confirmation of the IOV design through different coordinated actions with the EC and EUSPA, including the G2 system preliminary design review.
The contracts will provide Europe with the following capabilities:
G2SB1 satellite launch and early orbit phase, in-orbit testing and enhanced legacy services provision
G2 new capabilities in-orbit validation, including prototyping and validation of all the novel technologies that can exploit the full capabilities of the G2SB1 satellites.
Eleven contracts will be issued to manage in synchrony all the G1 and G2 assets for the coming years:
G2 IOV ground control segment (G2 GCS) for satellites monitoring and control
G2 IOV ground mission segment/secured facility (G2 GMS-GSF) for the production, dissemination and monitoring of all enhanced legacy services and the dissemination of new G2 advanced capabilities for validation
G2 IOV security monitoring (G2 SECMON), for the cyber/security monitoring of the system
G2 filling device (G2 FD), to ensure proper initialization of system assets
G2 system test bed (G2STB), to generate and monitor new G2 capabilities for validation of the G2G mission/services
G2 PRS test bed (G2PRSTB), similar to G2 system test bed but focused on advanced PRS capabilities for validation purposes
G2 security chain (G2SC), a test bed to ensure proper satellite-ground segment qualification before launch
Four system engineering support contracts (G2 SETA), where the main GNSS technical experts from different industries in Europe provide their support to ESA and EUSPA in their different fields of expertise.
These contracts are complemented by a significant set of system research and development and test tools, such as test user receivers and radio frequency constellation simulators.
G2G batch number one (G2SB1) satellites.
Galileo Second Generation System PDR
The Galileo Programme is not only focusing on short-term G2G development activities, but also looking forward to the future in terms of the consolidation and definition of G2G final operation capabilities. During the second half of 2022, more than 200 public representatives from the EC, EUSPA, ESA and Member States held countless meetings in the frame of the G2G system preliminary design review, which concluded in early December 2022.
As part of this review, the long-term implementation (G2G in orbit capability, or IOC, and final operational capability, or FOC) was reviewed and an agreement was reached on future steps. The evolution of Galileo capabilities will not only provide better services through advanced technical solutions, but will also ensure continuity of service and enhanced backward compatibility for first-generation legacy users.
Conclusions
The efforts of ESA and EUSPA continue with the aim of providing users continuous and stable services and evolving space and ground infrastructure to maintain Galileo competitiveness with the other global navigation satellite systems.
For analogous updates on the other three GNSS constellations, please see:
Russia’s space agency Roscosmos is suspending cooperation with Europe on space launches from the Kourou spaceport in French Guiana, including future Galileo satellite launches.
As reported by Rueters, Roscosmos chief Dmitry Rogozin said Saturday the action is in response to Western sanctions over Russia’s invasion of Ukraine.
“In response to EU sanctions against our companies, Roscosmos is suspending cooperation with European partners on space launches from Kourou, and is withdrawing its technical staff…from French Guiana,” Rogozin said in a post on his Telegram channel.
Russia’s decision will have “no consequences on the continuity and quality of Galileo and Copernicus services,” EU Commissioner Thierry Breton said in a statement. “This decision does not call into question the continuity of the development of these infrastructures either.”
“We are also ready to act with determination, together with the Member States, to protect these critical infrastructures in the event of an attack.”
“We will, in due course, take all the necessary decisions in response and resolutely pursue the development of the second generation of these two sovereign space infrastructures of the Union,” Breton said. “We are also prepared to act determinedly together with the member states to protect these critical infrastructures in case of an attack, and to continue the development of Ariane 6 and VegaC to guarantee the strategic autonomy with regard to carrier rockets.”
The Galileo program had already planned to shift to using Ariane 6 rockets for satellite launches. The launcher is undergoing the final stages of development, led by prime contractor ArianeGroup.
From 2023 onward, the remaining Galileo Batch 3 satellites will be launched with the new Ariane 62 launch vehicle, a variant of Ariane 6 with two strap-on solid boosters.
The most recent Galileo satellite launch took place on Dec. 5, 2021, using Soyuz launcher VS-26 to carry the first pair of Galileo Batch 3 satellites into orbit. The announcement will delay a Soyuz launch of two more Galileo satellites scheduled for April from French Guiana; a third pair of Galileo satellites was scheduled to launch in autumn on another Soyuz.
Galileo launch 11 from Europe’s spaceport in French Guyana. (Photo: ESA/CNES/Arianespace)
Authors Javier Benedicto (ESA), left, and Rodrigo da Costa (GSA). (Image: ESA)
Throughout 2020, the Galileo Programme under the responsibility of the European Commission, the European GNSS Agency (GSA) and the European Space Agency (ESA), has been delivering continuous and reliable global PNT and Search and Rescue (SAR) services, developed improvements to Galileo First Generation ground and space system infrastructure for increased robustness and new service capabilities, and launched a full modernization program aiming in the future at Galileo Second Generation.
The GNSS User Technology Report 2020 has just been released by GSA, providing a complete overview of the current status and trends of the GNSS worldwide market with focus on user technology and in particular European GNSS (Galileo and EGNOS) applications and services.
In addition to providing a high quality open service based on innovative signals in the E1 and E5 bands, Galileo is also the first GNSS constellation to comprise a SAR capability, including the provision of a return link to users in distress. Galileo also features unique capabilities, such as the provision of Navigation Message Authentication (OS-NMA) and of an encrypted navigation signal on E6, the Commercial Authentication Service (CAS). These functions will offer the first protection against spoofing available to civilian GNSS users.
Finally, Galileo will provide free access to a High Accuracy Service (HAS) through the use of an open data channel used to broadcast high-accuracy augmentation messages.
Performance Meeting Expectations
The Galileo constellation consists today of 22 operational spacecraft (24 satellites are available for the Search and Rescue service). Two additional satellites (GSAT0201/E18 and GSAT0202/E14) are currently under testing with regard to potential operational as auxiliary usage in the near future.
The long-term evolution of performance parameters reveals that the Galileo system is continuously improving. In particular, an excellent quality of the navigation message in terms of ranging accuracy can be observed. Since the Initial Service declaration in 2016, ranging accuracy has steadily improved reaching a level of ~25 cm (95%) by mid of 2020, see Figure 1.
FIGURE 1. F/NAV SISE as observed by user receivers (constellation average, 30 days moving average). (Image: ESA)
The timing accuracy benefits from the larger number of satellites in service. Figures 2 and 3 present the evolution of the UTC dissemination accuracy and GGTO accuracy performance better than 2.5 nsec and 4.2 nsec (95%) respectively, which are largely within Galileo service commitments.
Probably the most significant discriminator of Galileo versus other GNSS is its capability to broadcast multi-frequency (E1, E6, E5) signal components on all operational satellites. In the high-end and mid-range smartphone chipset market, dual frequency is becoming the norm. All large players have released dual-frequency chipsets, and the first dual-frequency chipsets targeting the budget device market are now becoming available. Dual-frequency receivers offer improved accuracy and robustness, and potential access to high-accuracy techniques. Multi-constellation is now standard for high-volume chipsets and Galileo with its multi-frequency capability is one of the largest GNSS contributors to this emerging dual-frequency PNT market.
Expanding Galileo Services Portfolio
Galileo offers the Galileo Open service (OS) for positioning and timing services, and Europe’s Search and Rescue (SAR) service contribution to COSPAS-SARSAT, equipped with its unique Return Link Message (RLM) declared operational in January 2020. Furthermore, the Galileo system is expanding its infrastructure capabilities such that, once fully operational, it will offer additional high-performance services worldwide.
Public Regulated Service (PRS) is restricted to government-authorized users for sensitive applications that require a high level of service continuity.
Open Service INAV message improvements on Galileo E1-B are under implementation, namely robust symbol level synchronization patterns, additional insertion of clock and ephemeris data with flexible outer encoding and frequent provision of shortened clock and ephemeris for improved robustness in terms of navigation data retrieval in challenging environments, in addition to facilitating a reduced time to first six (TTFF); these improvements ensure backwards compatibility with previously released OS SIS ICDs.
Open Service Navigation Message Authentication (OS-NMA) providing the free authentication of the Galileo Open Service (OS) for geolocation information through the Navigation Message (I/NAV) broadcast on the E1-B signal component.
Commercial Authentication Service (CAS), complementing the OS, providing a ranging authentication function implemented by encrypting the spreading code of the E6C (pilot) channel with a secret key. To ensure backward compatibility, CAS is based on the only civilian signal including cryptographic features (E6). When using both OS-NMA and CAS, users will benefit from data (navigation message) and range authentication, allowing PVT authentication worldwide.
Galileo Batch 3 satellite under test at ESA’s ESTEC facility in the Netherlands. (Photo: ESA)
High Accuracy Service (HAS) complementing the OS by delivering free access high accuracy data and providing better ranging accuracy, enabling users to achieve sub-meter level positioning accuracy.
Support to Safety of Life (SoL) Services through Dual Frequency Multi-Constellation (DFMC) SBAS and supporting the provision of integrity through the concept of Horizontal Advanced Receiver Autonomous Integrity Monitoring (H-ARAIM). In this context, the Galileo Integrity Failure Mode and Effect Analysis (IFMEA) Process is implemented through measurements and review of the system design, including characterization of feared events.
Galileo Batch 3 satellite under test at ESA’s ESTEC facility in the Netherlands. (Photo: ESA)
Infrastructure Modernization
The Galileo System infrastructure is being upgraded and modernized to support the full service portfolio, provide additional robustness and resilience, ensure security and improve operations.
The Galileo Ground Segment is being upgraded implementing ground segment virtualization technologies. This modernized infrastructure will make it possible to easily accommodate technology refresh and will minimize impact to Galileo service operations, under the responsibility of Spaceopal GmbH, during future deployment activities.
Current ground segment upgrades under production by prime contractor Thales Alenia Space in France (in charge of Ground Mission Segment and Security Monitoring) are addressing the deployment of improved robustness of the navigation and precise timing solutions, the full scope of PRS service capabilities, the expansion of the sensor station and up-link ground station networks, and additional security monitoring coverage to protect Galileo ground and space assets.
Ground segment upgrades under production by prime contractor GMV in Spain are addressing the deployment of a new Ground Control Segment providing increased constellation monitoring and control capabilities up to 38 satellites, enhanced operability features, expansion of the TTC network and additional security protection capabilities.
Upgrades of the Galileo Service Facilities are underway as well, notably the evolution of the GNSS Service Center toward the integration of the OS-NMA and HAS capabilities, and the extension of the reference measurement capabilities of the Galileo Reference Centre, by the prime contractor GMV in Spain. The robustness of the SAR service operations, under the prime contractor CNES in France, is also under improvement.
The production of 12 additional Batch 3 Galileo first generation satellites is proceeding, aiming at readiness for launch from mid 2021 onward. Batch 3 satellites are comparable to the 22 FOC satellites launched previously and built by the same prime contractor OHB Systems in Germany. With Batch 3 satellites, Galileo will reach its full constellation capability, including a number of in-orbit spares.
Galileo Batch 3 satellites will be progressively launched with the new Ariane 62 launcher vehicle, the two strap-on solid booster variant of Ariane 6, currently undergoing the final stages of development led by prime contractor ArianeGroup. Meanwhile, France’s space agency CNES is preparing the Ariane 6 launch facilities at Europe’s Spaceport in French Guiana. Ariane 6 is scheduled for its first launch in 2022.
Europe’s new Ariane 6 launch vehicle. (Artist’s concept: ESA)
Toward Galileo Second Generation
The Galileo Programme is fully engaged in the process of developing Galileo 2nd Generation (G2G). Procurement activities for system, satellite and ground segment have been initiated in 2020 with the ambitious goal of starting deployment of the new infrastructure in 2024.
The design of G2G is driven by overarching principles, including backward compatibility, providing an extended portfolio of services and the quality of services, but also the absolute need to meet user demands in a timely and effective manner. The European Commission, in close consultation with EU member states, has converged onto an ambitious set of long term PNT goals for the future European GNSS infrastructures.
G2G Service Portfolio and High-Level Mission Objectives agreed with Programme Stakeholders Service include service evolutions in the areas of signals evolution for increased performance and reduced complexity and power consumption at the user receiver level, time to first-fix, accuracy, authentication and other service attributes, PRS evolutions, advanced timing services, enhanced integration with terrestrial systems (5G/6G), complementarity with external sensors (such as INS, barometer, lidar) and application environments (such as low power devices and internet of things), SAR service evolution, Emergency Warning services, Space Service Volume and Ionosphere Prediction Service.
G2G will build on advanced navigation technology developed over the past 10 years under ESA’s European GNSS Evolution Programme (EGEP) and EU’s Horizon 2020 Programme. This technological leap will allow the early introduction of novel Galileo system features:
Open service capabilities (reduce power consumption and convergence time)
High-accuracy evolution (integrity, availability)
PRS robustness and transmit power
System and SIS in-orbit flexibility, reconfiguration and time-to-market
Inter-satellite links (ranging, mission dissemination, command and control)
SAR second-generation beacons
Reduce operations and maintenance cost
Accelerate time-to-market of new services
Ground technology virtualization and modernization
Acknowledging the changing nature of user requirements, the Galileo second-generation is designed to evolve incrementally and with sufficient flexibility to provide new services or signal features, if and when required, by dynamic reconfiguration of space and ground infrastructure.
By Javier Benedicto
Head, Galileo Programme department,
European Space Agency
Javier Benedicto, left, accept the 2018 GPS World Satellites Leadership Award on behalf of Giuliano Gatti of the European Space Agency, from Phil Froom of Rockwell Collins. (Photo: Melanie Beus)
Since the Galileo initial services declaration in December 2016, the Galileo Program has been providing global PNT and search-and-rescue services for users worldwide. The European GNSS Agency (GSA) just issued its GNSS 2019 Market Report in October, providing a complete overview of the current status and trends of the GNSS worldwide market with focus on European GNSS (Galileo and EGNOS) applications and services.
In parallel with service provision, the Galileo Program is undertaking extensive infrastructure development and deployment activities to reach Full Operational Capability (FOC), incorporating new service capabilities, but above all aiming at increasing the robustness and resilience of the system infrastructure, operations and service provision.
Galileo’s signal-in-space quality has steadily improved over the past few years, reaching in 2019 a best signal-in-space error (SISE) of about 0.25 meters (95%, global average; Figure 1). This has been achieved through a combination of several factors, including the increased number of operational satellites, enhanced versions of the Ground Mission Segment, and higher uplink rate of the navigation message (lower age of data). This performance is well within Galileo’s initial service accuracy commitments, as defined in the public Open Service – Service Definition Document (OS SDD).
Figure 1. Long-term historical SISE plot over a 30-day sliding window, constellation averaged. (Image: ESA)
Figures 2 and 3 (see page 40) show Galileo’s timing performance as broadcast UTC offset and GGTO accuracy. The evaluation was performed with calibrated GPS/Galileo timing receivers operated in UTC(k) laboratory (PTB, INRIM). Again, the initial timing service commitments have been fully met.
Probably the most significant discriminator of Galileo compared to other GNSS is its capability to broadcast multi-frequency (E1, E6, E5) signal components on all operational satellites. The position performance of a dual-frequency user receiver on-ground is shown in Figure 4. This measurement from June 2019 demonstrates a Galileo position accuracy well below 2 m (95%).
Figure 4. Galileo position accuracy performance, dual-frequency, June 2019. (Image: ESA)
With the aim of further improving the Open Service (OS) performance, three newly introduced I/NAV message improvements on Galileo E1-B are under implementation, namely FEC2 Reed-Solomon Clock and Ephemeris (CED), Reduced CED, and Secondary Synchronization Pattern (SSP). Galileo Open Service (OS) users will benefit from improved robustness in terms of navigation data retrieval in challenging environments, in addition to facilitating a reduced time to first fix. Those I/NAV improvements on Galileo E1-B are backwards compatible with previously released OS SIS ICDs.
In addition, Galileo infrastructure is currently being upgraded to provide means for OS authentication. The protocol proposed uses the E1B External Data Broadcast Service (EDBS) to provide authentication data to the user. The OS Navigation Message Authentication (NMA) is based on an adaptation of the Timed Efficient Stream Loss-tolerant Authentication (TESLA) protocol.
Beyond the OS, the Galileo system has been designed to allow for the dissemination of value-added data, such as high accuracy and authentication, in the E6B signal component. The component has been designed to broadcast the Galileo High Accuracy Service based on the provision of accurate satellite data (clocks, orbits and biases) and atmospheric data (mainly ionospheric corrections) to enable multi-frequency multi-constellation PPP with correction data transmitted through an open format in the Galileo E6B signal.
The introduction in early 2020 of the automatic acknowledgment of the SAR/Galileo Return Link Message (RLM) as part of the Cospas-Sarsat system will enable space assets to be used for search and rescue — persons in distress will get swift acknowledgement that their alert has been detected and located. The Return Link is the means to interact with a SAR beacon, improving the effectiveness of SAR operations. Extensive testing has demonstrated that the median latency for the reception of a return link message on the ground is 14.2 seconds, while 99% of messages are received within 57 seconds, after the request for the RLM transmission is delivered to Galileo (from Cospas-Sarsat to the RLSP). At the same time, the measured rate of reception was 100%, considering line-of-sight availability, thanks to the very robust Galileo navigation data link. This performance has been demonstrated to be uniform across the globe, as shown in Figure 5.
Figure 5. Beacon activation map and RLM delivery latency through the Galileo system. (Image: ESA)
Following the re-profiling of the Galileo Safety-of-Life (SoL) service, Galileo is meant to be exploited through dual-frequency multi-constellation (DFMC) SBAS and will support the provision of integrity through the concept of Horizontal Advanced Receiver Autonomous Integrity Monitoring (H-ARAIM). To allow the exploitation of Galileo for these SoL applications, a thorough analysis of the actual signal-in-space (SiS) performance and of potential feared events critical for SoL users is key. In this context, the Galileo Integrity Failure Mode and Effect Analysis (IFMEA) process is implemented through measurements and review of the system design, including feared-events characterization.
Ground Segment Brings Robustness
Galileo telemetry and telecommand ground station. (Photo: ESA)
Galileo’s Ground Segment is being upgraded to fully redundant control centers. These include processing and storage, monitoring and control facilities, and security monitoring centers. A worldwide network of Galileo Sensor Stations (GSS) allows monitoring and measuring of satellite signals; uplink stations allow dissemination of the navigation message to users through Galileo satellites; and telemetry, tracking and control (TTC) stations allow monitoring and control of the satellites.
Ground segment upgrades under production by Thales Alenia Space France (in charge of the ground mission segment and security monitoring) and GMV Spain (in charge of the ground control segment) are addressing increased service robustness, through the introduction of a more flexible infrastructure with a significant technology refresh, improved security, service continuity, enhanced service performances, and enhanced operability features.
One important objective of the ongoing upgrades is to implement a modern infrastructure, based on leading virtualization technologies. This modernized infrastructure will make it possible to easily accommodate hardware and software changes without requiring significant redesign or requalification, and will minimize the impact to Galileo service operations — under responsibility of Spaceopal GmbH — during future deployment activities.
Batch 3, Ariane 6 Under Production
Ariane 6 on the launchpad. (Artist’s concept: ESA)
The production of Batch 3 of 12 additional Galileo FOC satellites is proceeding, aiming at readiness for launch by the end of 2020 onward. The satellite design includes a selected number of improvements compared to the 22 FOC satellites launched previously and built by the same satellite manufacturer OHB Systems.
The different stages of assembly, integration and initial test phase in the OHB production plant in Bremen have already started, before shipment to ESA-ESTEC in the Netherlands for the environmental test campaign consisting of thermal vacuum, mechanical tests, interface verification with the launcher and system end-to-end performance tests with the elements of the Galileo ground segment.
Following the phasing out of the Ariane 5 SE launcher, the third batch of Galileo satellites will be progressively launched with the new Ariane 62 launcher vehicle, the two solid-booster variant of Ariane 6 now in the final stages of development.
Evolution to Meet User Needs
The Galileo Second Generation roadmap has achieved maturity in 2019 and is now entering the preliminary design and implementation phase. Based on the EU’s H2020 Galileo Second Generation activities managed by ESA, and the GSA prospective market analysis, the European Commission, in close consultation with EU member states, has agreed on an ambitious set of long-term PNT goals for the future European GNSS infrastructures.
Technology pre-developments, critical engineering activities and synergic design activities between space and ground infrastructure are being conducted. This will translate into the progressive deployment of a complete set of space/ground infrastructure that is tailored to satisfy the diversified user needs in four main dimensions:
Satellite and ground segment infrastructure with capabilities that can dynamically adapt to current and future user needs. Key drivers are flexibility and robustness, ensuring fast time to market to meet user needs.
Full synergy between GNSS and SBAS systems infrastructure, to complement and enhance the service portfolio. This will allow segmentation and complementarity of safety-critical services and extension to all new PNT services available today, including high-accuracy positioning integrity.
Enhanced integration with terrestrial systems — 5G/6G, signals of opportunity (SOOP), terrestrial beacon systems (TBS). ESA and GSA have been actively leading the 5G positioning standardization worldwide in collaboration with public and private institutions inside 3GPP and will soon move toward the start of standardization of 6G terrestrial positioning and GNSS interconnection technologies.
Full complementarity with external sensors (such as INS, barometer and lidar) and application environments (low-power devices and internet of things) so that the Galileo Second Generation Infrastructure enhances and complements the capabilities provided by these external means.
A key pillar for this long-term strategy is the Galileo transition satellites. The competitive procurement procedure for the first batch of transition satellites is coming in 2020. The flexibility and robustness of these satellites will allow the European PNT infrastructure to satisfy all the different user needs in the next decade. This procurement — together with others at system, ground segment and technology level — will enable the start of the in-orbit validation of second-generation capabilities from 2025 onward.
Additional ground and test infrastructure are in early engineering analysis, design and technology development, in order to proceed with additional procurements for experimental and operational usage, starting early in the 2020s.
It was not a big wager as wagers go, at least not in monetary value, but the underlying premise of the wager spoke volumes. It all began innocently enough in 2005 when the first test, or proof of concept, Galileo satellite known as GIOVE-A was launched.
In March of that year, a group of PNT experts made a simple wager that there will be:
10 or fewer operational Galileo satellites by 12/31/15
or
11 or more operational Galileo satellites by 12/31/15
Galileo’s GIOVE-A retired in June 2012.
About 20 PNT experts took the bet, evenly divided on both sides, which essentially said that given that the first test (GIOVE) Galileo satellites were launched in 2005 and 2008 respectively, surely there would be at least 10 operational satellites on orbit or about one per year by 2015.
The stakes were modest, but as I said, the import of the faith (or lack of faith) in the European Union and its ability and understanding of the difficulties involved in the Galileo endeavor spoke volumes. As the chief scientist at Air Force Space Command stated at the time, “This is rocket science; this is hard.”
Chutzpah and/or naïveté
But the Europeans refused to believe it was a very hard problem. Indeed, after the second GIOVE launch, GIOVE-B in 2008, the European ministers announced, with incredible chutzpah and/or naïveté, that the Galileo constellation would be fully operational (24 fully operational on-orbit satellites) by 2013.
Of course, nothing of the sort has happened. Following the in-orbit validation (IOV) satellites, the first operational satellite launch did not occur until October 2011, almost six years later.
As of May 2016, there were 12 operational Galileo satellites on orbit along with two in early orbit or checkout stages — a far cry from the predicted 24 operational satellites. This is not a criticism of the Galileo system; rather, a validation of those who took the pessimistic side of the wager and of the chief scientist who clearly stated the obvious: this is indeed, as a popular euphemism states, a DARPA hard problem.
So the Europeans have been going about this PNT business since the initial decision to proceed in 2003 — 13 years. The United States has been producing and launching GPS satellites continuously since the first test launch of a NAVSTAR satellite in 1977 (39 years), with a continuously fully operational system (FOC) since 1995 (21 years), and guess what? It is still a hard problem. No one denies that. Which brings us to GPS III.
GPS III Update
Since the United States — specifically the United States Air Force (USAF) — has been in the space-borne PNT business longer than any other nation, you would think we would have this down by now. But it is still a hard problem with, fortunately, a long string of successes and very few (only two) failures.
To date, the U.S. government has launched a total of 72 GPS satellites. There are 31 active operational GPS SVs (satellite vehicles) on orbit, with seven additional in residual or test status; 32 have been retired into a parking orbit where they will not interfere with the operational constellation. That equates to 1.85 GPS satellites launched per year on average, or one every 6.5 months — an enviable record, failures and all.
Plus, there are GPS IIA satellites still on orbit that have been there for more than 22 years. Not bad for a satellite built to last (contracted service life) for 7.5 years.
Amazingly, the payloads on every GPS satellite to date were built, in part, in partnership with or completely by one company, now known as Harris, nee Exelis, nee ITT. Of course, the complexity of the payloads being built by Harris for the GPS III satellites is a far cry from the payloads built in 1975 for launch in 1977. According to GPS III program manager and VP Mark Stewart and his cohorts at Lockheed Martin (LMCO), the aerospace company building the GPS III satellites, GPS III
“…will deliver three times better accuracy, provide up to eight times improved anti-jamming capabilities and extend spacecraft life to 15 years [ed. contracted life], 25 percent longer than the [ed. latest family of satellites on orbit today]. GPS III’s new L1C civil signal … will make it the first GPS satellite to be interoperable with other international global navigation satellite systems.”
While many of you may look upon that LMCO statement as marketing hype, in fact it is a rather incredible prophesy. To a PNT expert it translates to: almost all GPS users globally will have sub-meter level positional accuracy from a group of signals that will rarely if ever be completely jammed, from an SV with a projected lifetime of 30 years that has more signals and greater signal strength, flexibility and interoperability than ever before. By the numbers GPS is still, far and away, the world’s gold standard.
So exactly where are we in relation to a launch of the first evolutionary GPS III satellite? After all, the last IIF launch, number 12 in the series, built by Boeing, occurred in February, so by the law of averages we should have the first GPS III launch later this month. That is not going to happen, but then what is a few months among friends when iterated over 39 years?
Currently the first GPS III launch date, according to the USAF, is scheduled for May 2017. All indications are the government is on track to meet that date with, interestingly enough, the availability of a suitable launch vehicle being the LIMFAC (limiting factor), not the availability of an GPS III SV to launch.
SV 01 in testing at Lockheed Martin’s Denver facility. (Photo: LMCO)
According to my sources, GPS III SV-01 is fully integrated, has completed all environmental testing and is essentially ready to ship to Cape Canaveral,. It would be available for launch (AFL) sometime before the end of the calendar year if there were a launch vehicle, a ground control system and range availability.
GPS III SV-02 will undergo full integration (“core-mating”) completion sometime this fall and — following successful completion of its environmental tests — should certainly be AFL in 2017.
The complete navigation panel (from Harris) for GPS III SV-03 should arrive in the LMCO Denver facility early next year. Providing the vehicle stays on track through testing, it should be AFL in 2018.
The government has yet to complete the contract award process for GPS III vehicles SV-09 and SV-10 to LMCO, but I am assured the award is imminent.
My sources confirm that Harris is continuing to pump money, expertise and technology into the GPS III payload development process, a manufacturing tour de force, and the company should be back on schedule early next year.
As for OCX, the future GPS Ground Control Segment, that is another tale for another time. For all other GPS III segments, all in all it is a positive message for development and deployment. Which is an admirable feat — after all, it is rocket science!
By the way, the Galileo wager is open to interpretation. There were certainly more than 10 Galileo platforms on orbit on the last day of December 2015, but only nine of them were operational at the time. Both sides are claiming victory. What a surprise!
A product to save your hearing
The EB15LE with Hearing Defenders with accessories. (Photo: ERI)
Before I close, I want to mention a product I have tested as extensively as I can in a limited environment. I agreed to test this non-GPS product because of all the emails and letters I receive concerning tinnitus and how it negatively affects our warfighters. Several emails make clear the necessity and criticality of a good sight picture or display for GPS guidance, especially where exfiltration is concerned.
When warfighters or law enforcement officers are suffering the ill effects of extremely loud noises, it is often disorienting. Much like the effects of a flash-bang device, a victim can lose his bearings and needs to have a clear visual of how to exit the threat environment.
The best solution would be not to suffer the devastating effects of the loud noises in the first place. This is where a company named Etymotic Research Incorporated (ERI) comes into play. ERI has developed electronic hearing protection for law enforcement officers and military users.
The version I tested was designated the EB15 for law enforcement. It functioned well as electronic hearing protection and amplification where needed. The device is essentially an electronic hearing aid that amplifies natural or quiet sounds up to five times, and a hearing defender that electronically blocks loud, harmful sounds by up to 25 decibels.
While I was not able to test the hearing defenders in actual combat, the testing I did perform demonstrated that the EB15-LE is an impressive product with a plethora of earplugs for various noisy environments that may help save a user’s hearing. Our warfighters and law-enforcement officers deserve the best technology available, especially if it helps them retain their orientation in a dangerous environment and saves their hearing.
Until next time, happy navigating, and remember: GPS is brought to you free of charge courtesy of the USAF.
The European Space Agency (ESA) has named Paul Verhoef its new Director of Galileo Programme and Navigation-Related Activities. Verhoef, former coordinator for Galileo activities with the European Commission, was named as one member of a new senior leadership team after a special meeting of the ESA Council in Paris on Nov. 21.
At the weekend meeting, the agency selected several new managers for key positions. The new leadership team is expected to start work in early 2016.
Space Applications
Director of Telecommunications and Integrated Applications (D/TIA), Magali Vaissiere
Director of Galileo Programme and Navigation-Related Activities (D/NAV), Paul Verhoef
Science and Exploration
Director of Science (D/SCI), Alvaro Giménez Cañete
Director of Human Spaceflight and Robotic Exploration Programmes (D/HRE), David Parker
Space Technology and Operations
Director of Technical and Quality Management (D/TEC), Franco Ongaro
Director of Operations (D/OPS), Rolf Densing
Administration
Director of Internal Services: Human Resources, Facility Management, Finance and Controlling, Information Technology (D/HIF), Jean Max Puech
Director of Industry, Procurement and Legal Services (D/IPL), Eric Morel de Westgaver
