The Global Navigation Satellite System (GNSS), originally designed to support Positioning, Navigation, and Timing (PNT) services for terrestrial users, is becoming a fundamental backbone of the current and upcoming space applications. Effort are ongoing at international level to define an Interoperable GNSS Space Service Volume (SSV), aiming to establish GNSS PNT performances from Low-Earth Orbits (LEO) to Highly Elliptical Orbits (HEO) and beyond. The European Galileo GNSS system plays a key role, whit its navigation performance in space continuously improving through the integration of new input and tools. This paper provides insight into the activities currently carried out at the European Commission's Joint Research Centre (JRC) and aims to renovate its SSV testing capabilities. The focus is on the recently developed JRC Integrated SSV test bench (JRC-ISSVTB), allowing the assessment of SSV key performance parameters (KPI) with an improved level of representativeness. The solution integrates all available up-to-date information about the Galileo system capabilities, including antenna pattern modelling, and introduces a novel hardware-in-the-loop (HIL) based verification step. The test bench architecture and the calibration steps are described, along with the configuration implemented to customize the environment for different orbit regimes. The preliminary results presented here offer an additional reference for upcoming SSV applications and set the stage for a complete characterization of the Galileo SSV to be included in the next update of the interoperable GNSS Space Service Volume.

In the context of the Jammertest 2023, a collaborative experiment was carried out by the European Commission Joint Research Centre (JRC), the European Space Operations Centre of ESA (ESOC), the Norwegian Communication Authority, and the Norwegian Defense Research Establishment (FFI) to explore potential RF interference monitoring in the navigation GNSS band from LEO. The experiment utilizes the ESA OPS-SAT satellite and the possibility of transmitting a custom jamming signal pattern during the Jammertest event. The objective is to validate the feasibility of detecting and locating ground-generated jamming signals using SDR technology on-board LEO. The insight into the signal structure and location provides a unique chance to assess the performance and limitations of this approach in a real-world scenario. This paper presents the processing of raw RF data collected during the in-flight experiment, including the generation of frequency difference of arrival (FDOA) observables and emitter geolocation. Despite the constraints posed by onboard resources and mission limitations, this work offers a persuasive proof of concept and suggests new guidelines for implementing this technology on future LEO missions.

Utilization of GNSS receivers on-board a Geostationary platform is becoming an attractive alternative for position and timing determination for ground operations and cost minimization. To increase competitiveness, the use electric propulsion to perform or complement the transfer manoeuvres to GEO orbit is nowadays employed. This imposes long duration orbits that intersect several times the “GNSS sphere” (the sphere of center the Earth’s center and radius equal to the semi-major axis of the GPS orbits - approx. 26500 km – or GALILEO orbits at ~ 29300 km), where GNSS performances are strongly influenced by the availability of measurements to the GNSS Receiver. In this paper we will review the first results and the return of experience of the first commercial GNSS receiver embarked on the NEOSAT Platform made by Thales Alenia Space, which, according to the authors, is the first European multi-constellation (GPS+GALILEO) operational receiver that was experiencing a fully electric Orbit Rising to GEO orbit (of a duration of about 6 months), geostationary positioning and, according to the authors knowledge, first-in-the-world to provide tracking of GALILEO signals in Geostationary orbit (i.e. above the GALILEO sphere), enabling the use of the full Space Service Volume up to GEO stationary altitude and more for commercial applications.

The rapid development of Low Earth Orbit Position, Navigation, and Timing (LEO-PNT) constellations presents opportunities to augment Global Navigation Satellite Systems (GNSSs) with additional signals from Low Earth Orbit (LEO) satellites, thereby improving performance and reliability for users. This research study addresses the challenges posed by the interdependency between LEO and GNSS layers, which can lead to cascading faults. By extending Receiver Autonomous Integrity Monitoring (RAIM)-like capabilities to spaceborne receivers, specifically through Timing Receiver Autonomous Integrity Monitoring (T-RAIM), this paper aims to mitigate these risks. This study validates the integration of T-RAIM with advanced Precise Real-Time On-board Orbit Determination (P2OD) techniques in LEO scenarios using a hardware-in-the-loop test environment. The findings demonstrate that the architecture with T-RAIM can maintain nominal positioning and timing accuracy even in the presence of GNSS clock faults, ensuring continuous system functionality without requiring P2OD restarts. This capability is crucial to preventing service interruptions and enhancing the robustness of LEO-PNT solutions. The proposed integration handles the computational load and complexity while accommodating the limited resources of spaceborne receivers, offering a viable and robust LEO-PNT solution. The experimental results show that T-RAIM effectively mitigates the impact of pseudorange ramp errors, maintaining stable clock bias and preserving the integrity of orbit determination and time synchronization.

LEO-PNT systems are poised to revolutionize GNSS by delivering superior resilience, accuracy, and robustness. This paper presents a novel Hardware-in-the-Loop (HIL) evaluation of integrating LEO-PNT augmentation into kinematic Precise Point Positioning (PPP) for dynamic users. Conducted at the Joint Research Centre (JRC) facilities, the study utilizes a comprehensive, end-to-end test bed that includes RF signal generation for a multi-tier LEO-PNT constellation, the integration of the innovative STMicroelectronics Teseo VI LEO-compatible receiver, and a dedicated, configurable PPP algorithm capable of processing HIL-generated raw measurements. Our results demonstrate the substantial benefits of LEO-PNT augmentation in significantly improving positioning accuracy within challenging, high-dynamic automotive scenarios. Crucially, this study underscores the critical role of HIL testing in stress-testing and identifying specific areas for enhancement in both receiver hardware and algorithm implementation—essential steps for the successful, real-world deployment of LEO-PNT technologies.