In the rubidium atomic frequency standard (RAFS), an rf-discharge lamp produces the device’s atomic signal. As a consequence of the light-shift effect, variations in the lamplight’s intensity result in variations in the RAFS’ output frequency. While the basic physics of the light-shift is reasonably well understood, the temporal variations in the lamp’s light intensity are not. Here, we describe our analyses of lamplight intensity jumps occurring for the RAFS onboard GPS-IIR satellites. Briefly, we find that lamplight intensity jumps correspond to a compound Poisson process. The magnitude of the jumps appears to be a mean-zero random process with a family-wide standard deviation of 0.1%. The time between jumps corresponds to a Poisson process, and there appear to be two timescales associated with the jumps: a “fast” timescale, with a mean time between jumps of 7 days, and a “slow” timescale with a mean time between jumps of 180 days.

On-orbit GPS RAFS lamplight variations: statistics of lamplight jumps / Formichella, Valerio; Camparo, James; Tavella, Patrizia. - ELETTRONICO. - (2017), pp. 291-298. (Intervento presentato al convegno 48th Annual Precise Time and Time Interval Systems and Applications Meeting, PTTI 2017 tenutosi a Hyatt Regency Monterey, Monterey, California (USA) nel January 30-February 2, 2017).

On-orbit GPS RAFS lamplight variations: statistics of lamplight jumps

FORMICHELLA, VALERIO;TAVELLA, PATRIZIA
2017

Abstract

In the rubidium atomic frequency standard (RAFS), an rf-discharge lamp produces the device’s atomic signal. As a consequence of the light-shift effect, variations in the lamplight’s intensity result in variations in the RAFS’ output frequency. While the basic physics of the light-shift is reasonably well understood, the temporal variations in the lamp’s light intensity are not. Here, we describe our analyses of lamplight intensity jumps occurring for the RAFS onboard GPS-IIR satellites. Briefly, we find that lamplight intensity jumps correspond to a compound Poisson process. The magnitude of the jumps appears to be a mean-zero random process with a family-wide standard deviation of 0.1%. The time between jumps corresponds to a Poisson process, and there appear to be two timescales associated with the jumps: a “fast” timescale, with a mean time between jumps of 7 days, and a “slow” timescale with a mean time between jumps of 180 days.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2675111
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