TerraStar X Technology: Design of GNSS Corrections for Instantaneous Lane-Level Accuracy on Large Scale Connected Vehicles and Devices

Leos Mervart, Zdenek Lukes, Paul Alves

Abstract:	Applications across multiple industries require Global Navigation Satellite Systems (GNSS) for high-precision positioning. However, the standalone GNSS performance using the typical, low-cost GNSS devices in vehicles today is insufficient to achieve the positioning and availability needed for instantaneous lane-level accuracy on connected vehicles at scale. The antenna and receiver hardware available in standard vehicles limits the position accuracy and convergence performance. These limitations make the positioning more susceptible to local error sources like receiver multipath, noise, carrier tracking stability, etc. To work within the constraints of automotive-grade GNSS devices and achieve the performance required for lane-level positioning, GNSS correction services with additional design considerations and sophisticated algorithms are needed. NovAtel’s TerraStar X technology enables these applications and consists of many components, including a network of reference stations, data dissemination links, innovative messaging formats, account management and monitoring tools. At the heart of this service is the Orbit and Clock Determination System (OCDS). The OCDS produces a set of corrections precise satellite orbits and clocks, and satellite-specific biases for individual signals augmented by the computation of additional regional corrections. The addition of regional corrections enables automotive and mass-market applications to achieve in-lane positioning within seconds, using any dual-frequency, dual-constellation GNSS hardware. This paper outlines the design and performance of the combined OCDS and regional correction system. The result is cutting-edge software that provides a continuous stream of multi-constellation, multi-frequency GNSS corrections, enabling a correction service that enables the affordable GNSS device ecosystem. We demonstrate the performance of the TerraStar X technology across a variety of applications. In addition to providing support for lane-level positioning in less than a minute for automotive applications, regional corrections are shown to improve the performance of survey-grade GNSS receivers.
Published in:	Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022) September 19 - 23, 2022 Hyatt Regency Denver Denver, Colorado
Pages:	1280 - 1292
Cite this article:	Mervart, Leos, Lukes, Zdenek, Alves, Paul, "TerraStar X Technology: Design of GNSS Corrections for Instantaneous Lane-Level Accuracy on Large Scale Connected Vehicles and Devices," Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022), Denver, Colorado, September 2022, pp. 1280-1292. https://doi.org/10.33012/2022.18535
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