NIST researchers recently demonstrated that optical atomic clocks can make frequency ratio measurements with 18-digit accuracies [1], a significant advance towards the future redefinition of the second, with implications for GPS accuracy and dark matter detection. However, these optical clocks are more prone to down time than the microwave clocks used in the past, creating “gappy” data which often strain, or outright violate, the assumptions underlying the statistical models currently used. This project centers around investigating and advancing our new and improved method for the analysis of clock data using a multitaper spectral analysis approach [2]. The fundamental methodology around frequency stability analysis of clock data hasn’t been revisited in decades; our goal is to develop a suite of suitable statistical tools which allow clock scientists to properly analyze data with gaps. Additionally, we aim to provide comprehensive documentation to facilitate the successful adaptation and implementation of this new approach by the scientific community at large. 

[1] Boulder Atomic Clock Optical Network (BACON) Collaboration. Frequency ratio measurements at 18-digit accuracy using an optical clock network. Nature 591, 564–569 (2021). https://doi.org/10.1038/s41586-021-03253-4 

[2] Chave, A. D. (2019). A multitaper spectral estimator for time-series with missing data. Geophysical Journal International, 218(3), 2165-2178.

key words

spectral analysis; multitaper spectral estimation; missing data; time series; exploratory data analysis

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral applicants