CSAC Temperature Calibration for Improving GNSS Positioning Performance

Enric Fernandez, David Calero and M. Eulàlia Parés

Abstract:	Current GNSS (Global Navigation Satellite System) receivers include an internal quartz oscillator (or similar) limited by the frequency stability and a poor accuracy, being one of the main sources of uncertainty in the navigation solution (also multipath and ionosphere effects are an important error sources.) Replacing the internal TCXO (Temperature Compensated Crystal Oscillator) clock of GNSS receivers by a higher frequency stability clock such a CSAC (Chip Scale Atomic Clock) oscillator could improve the navigation solution in terms of positioning accuracy, availability signal recovery, multipath and jamming mitigation and spoofing attacks detection. For achieving these benefits, the deterministic errors from the CSAC need to be modelled, by determining and predicting the clock frequency stability in the positioning estimation process. This approach is also known as clock coasting, getting rid of the clock error parameter and being able to obtain a position with only three satellites. The research presented in this paper aims to go a step beyond, analyzing the correlation between the temperature and the clock stability noise and the impact of its proper modelling in the positioning performance. In addition, the deterministic errors from the oscillator are deeply evaluated (taking into account the effects of temperature and aging.)
Published in:	Proceedings of the 47th Annual Precise Time and Time Interval Systems and Applications Meeting January 25 - 28, 2016 Hyatt Regency Monterey Monterey, California
Pages:	36 - 44
Cite this article:	Fernandez, Enric, Calero, David, Parés, M. Eulàlia, "CSAC Temperature Calibration for Improving GNSS Positioning Performance," Proceedings of the 47th Annual Precise Time and Time Interval Systems and Applications Meeting, Monterey, California, January 2016, pp. 36-44. https://doi.org/10.33012/2016.13148
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