FocalPointUK - Real-time S-GNSS receiver
Last Updated: 18/07/2024 08:12 Created at: 18/07/2024 08:12
Final Presentation of NAVISP Project EL2-119 now available:
Global Navigation Satellite Systems (GNSS) have revolutionized positioning and navigation, but their performance in urban environments remains a significant challenge. High-accuracy techniques like Real Time Kinematics (RTK) and Precise Point Positioning (PPP) face limitations in dense urban areas due to signal interruptions, blockages, and multipath effects caused by buildings and structures. These factors compromise positioning accuracy and reliability, hindering GNSS applications in critical sectors such as safety systems, autonomous vehicles, and high-precision location-based services. Additionally, the increasing prevalence of GNSS spoofing attacks presents security risks. Current solutions often need specialized hardware or complex antenna arrays, impeding widespread implementation.
To address these challenges, FocalPoint Positioning developed S-GNSS, a novel software-based technology enhancing consumer-grade GNSS receiver capabilities without hardware modifications. S-GNSS technology correlates multiple GNSS received signals based on their angle-of-arrival (direct line of sight and other signals arriving as a consequence of multipath effects) improving receiver sensitivity, effectively providing a 5-10 dB performance boost. This technology enhances positioning accuracy and integrity in urban environments through two primary mechanisms: 1) rejection of reflected and spoofing signals via angle-of-arrival analysis, and 2) improved tracking of weak line-of-sight signals due to increased sensitivity. Supercorrelation has demonstrated effectiveness for both L1/E1 and L5/E5 signals, indicating broad applicability across GNSS frequencies.
Within this NAVISP project, Focal Point Positioning developed a fully productionized real-time S-GNSS receiver. This receiver serves dual purposes: i) as a trial platform for GNSS chipset manufacturers and; ii) as a potential solution for end-users in high-security sectors requiring robust, high-accuracy positioning in challenging urban environments. The project encompassed the development of both hardware and software components. The hardware utilized Commercial Off-The-Shelf (COTS) components, including a standard PC, an NT1065-USB3 NTLab RF Front End configured for GPS and Galileo signals, and Focal Point's proprietary INS sensors unit. The software component, S-GNSS SDR, is a configurable C++ application supporting comprehensive GNSS signal processing. It facilitates acquisition and tracking of multiple GPS and Galileo signals, operates in both real-time and offline modes, and can process up to 40 signals simultaneously. The software incorporates advanced features such as high tracking sensitivity, a Navigation Engine with Sensor Fusion, Vector Tracking, and S-GNSS closed loop operation, enhancing performance in challenging environments.
A significant milestone in the project was the development and evaluation of a complete S-GNSS receiver using live data recordings from a custom-built trials system. Correlation analysis, including Skyscan processing, yielded promising results. Initial live data tests demonstrated substantial improvements in both GNSS measurement quality and positioning performance, particularly in challenging environments such as deep urban canyons. These enhancements in raw measurements and Position, Velocity, and Time (PVT) accuracy underscored S-GNSS potential to address longstanding issues in urban GNSS positioning.
Future development efforts aim to expand support for additional GNSS constellations and optimize the utilization of improved measurement accuracy within the PVT solution.
The project was part of NAVISP Element 2, which aims to maintain and improve the capabilities and competitiveness of the participating States' industry in the global market for satellite navigation and, more broadly, PNT technologies and services.
For more information, please review the Final Presentation slides or visit FocalPoint.