SPARTN: The First Open GNSS Data Standard that Enables Safe and Accurate GNSS Localization for Automotive Applications

Abstract

Global Navigation Satellite Systems (GNSS) are a vital component for automotive applications which require an accurate and reliable absolute localization solution robust against multiple failure modes. Although GNSS has become common in many of our devices, standalone GNSS does not achieve the accuracy or safety requirements for automotive system manufactures. To resolve this problem GNSS correction service providers have begun broadcasting correction and integrity information to augment the performance of standalone GNSS. As the number of OEM GNSS equipment manufactures and correction service providers continues to grow, the reliance on proprietary, closed communication protocols limits end-user’s flexibility. For this reason, the Safe Position Augmentation for Real-time Navigation (SPARTN) format has been developed by a consortium of GNSS service providers and OEM GNSS equipment manufactures to establish an open, state-of-the art communication standard for GNSS corrections. Released in January 2020, the SPARTN format provides an industry recognized standard that supports wide and global area broadcasts through a combination of low bandwidth, accuracy, availability, reliability, and integrity for safety of life applications. The format has been design with the ISO 26262 and IEC 61508 safety standards in mind and has already been implemented by multiple users for safety critical applications. The SPARTN format offers flexibility for service providers to tailor their solution to the end-user specifications. Currently, support for all major GNSS including GPS, GLONASS, Galileo, BeiDou and QZSS are provided along with the capability to support the large selection of signal and track types. Additionally, the format has support for proprietary messages which may allow service providers even more flexibility to differentiate their service against their competitors by providing supplementary information. The format inherently supports encryption and authentication concepts to protect confidentiality and ensure the origin of the correction data. Currently users of the format can take advantage of state-of-the-art security algorithms which consider a 15+ year horizon, can operate in both resource constrained environment as well as integrate with hardware security modules, and are scalable to an unlimited number of users. From a GNSS integrity view point, the format incorporates many of the concepts recommended for state-of-the art receiver autonomous integrity monitoring (RAIM) algorithms including system design parameters such as probability of failures, GNSS network design parameters for threat modelling at the end-user along with the traditional line-of-sight and atmosphere quality indicators. The presentation will provid an update on the current status of the format, provide a road map for future feature support, demonstrate performance in automotive environments and discuss opportunities for service providers and position engine clients to benefit from the open format.