Impact of turbulent phase noise on frequency transfer with asymmetric two-way ground-satellite coherent optical links

8th Symposium on Frequency Standards and Metrology 2015

Robert, Clélia^1 ; Conan, Jean-Marc^1 ; Wolf, Peter^2

Onera - the French Aerospace Lab, Châtillon

F-92322, France^1

SYRTE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, LNE, 61 avenue de l'Observatoire, Paris

75014, France^2

关键词: Atmospheric effects;    Coherent optical links;    Differential phase;    End-to-end simulation;    Frequency transfer;    Heterodyne efficiency;    Temporally resolved;    Turbulence-induced scintillation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/723/1/012039/pdf
DOI  :  10.1088/1742-6596/723/1/012039

来源: IOP

【 摘 要 】

Bidirectional ground-satellite laser links suffer from turbulence-induced scintillation and phase distortion. We study how turbulence impacts on coherent detection capacity and on the associated phase noise that restricts clock transfer precision. We evaluate the capacity to obtain a two-way cancellation of atmospheric effects despite the asymmetry between up and down link that limits the link reciprocity. For ground-satellite links, the asymmetry is induced by point-ahead angle and possibly the use, for the ground terminal, of different transceiver diameters, in reception and emission. The quantitative analysis is obtained thanks to refined end- to-end simulations under realistic turbulence and wind conditions as well as satellite cinematic. These temporally resolved simulations allow characterizing the coherent detection in terms of time series of heterodyne efficiency for different system parameters. We show that Tip/Tilt correction on ground is mandatory at reception for the down link and as a pre-compensation of the up link. Good correlation between up and down phase noise is obtained even with asymmetric apertures of the ground transceiver and in spite of pointing ahead angle. The reduction to less than 1 rad2of the two-way differential phase noise is very promising for clock comparisons.