LNE-SYRTE, Observatoire de Paris, France, is opening a post-doc position in:

Comparison of advanced time and frequency transfer techniques

Avr 29, 2023


The postdoctoral researcher will work on the development of means of comparison of time and frequency transfer techniques in the microwave and in the optical domains, based on the assessment of their ultimate performances. Considered techniques include GNSS Common View and Two-way on one hand, fibered and free-space optical links on the other hand.

The goal of the project is to study the performances of the time and frequency transfers performed using different methods, focusing especially on quantifying the exact instrumental biases related to each one of them. This project ambition is to lay the foundations for multi-techniques comparisons, which could be operated conventionally in the future as a mean of improvement and robustness of time and frequency references, and also as a mean of continuous monitoring of free-space propagation delays over different lengths of baselines and their exploitation for Earth sciences.


Performed work will be both experimental and theoretical.

The postdoctoral researcher will develop and deploy the modeling tools necessary to the design of the experiment (propagation model), and to the analysis of the future experimental results.

He or she will develop an experimental work with a calibration bench dedicated to the characterization of multi-techniques comparison platforms. Beyond the instrumentation capacity, the focus will be on the interfaces between each technique, by defining clearly the reference plans and calibration methods.

Indeed at the ps level, ps uncertainty corresponds to path imbalances of a fraction of mm, so that even the number of gates in the FPGA (routing) matters, and any electronics component with delay in the µs-ns range requires a control with a fraction of microsecond.


The candidate should hold a PhD. The researcher profile should be that of a physicist, with an optics or electronics background, with skills and interest for experimentation and modeling. Any experience in time and frequency metrology is appreciated. Rigor, communication and team work are necessary skills.

Work Context

The postdoctoral researcher will join the team « Optical Frequencies Metrology » at SYRTE, leader research laboratory in time and frequency, demonstrating one of the best international realizations of UTC. He or she will work under the direction of Caroline Lim, Research Engineer of the National Lab for Metrology, and of Paul-Eric Pottie, CNRS Research Engineer and co-PI of the REFIMEVE research infrastructure, which is the French fiber network for ultra-stable frequency reference distribution. He or she will work within the framework of a collaboration between SYRTE and several academic and industrial partners: Besançon Observatory, GEOZUR Observatoire de la Cote d’Azur, and CNES.

The project is fully funded by FIRST-TF LabEx (ANR-10-LABX-48-01).

It will be possible to extend the 12 month initial contract.

Start date: Oct. 2023, to be discussed

Work place: SYRTE, Observatoire de Paris, Paris, France

Field: Time and frequency transfer, optical fiber, satellite links, precise measurements


Send a motivation letter, a CV with list of publications, and the name and contact information of two references before July 31th, 2023 to:

Caroline Lim