GRD seminar Laurie Paillier [ONERA]

Laurie Paillier research engineer at ONERA will present her work about optical links from ground to space. Here is an abstract of her presentation :

Both the increasing imaging resolution of earth observation satellites and the advent of a space based globalized internet are currently urging for very high data rate transmissions between space and ground. With the promise to provide tens of Gbps per channel, optical links may become a major breakthrough technology, assuming that the
technological assets developed for the fibered networks can be exploited. Especially, phase modulation techniques have demonstrated their tremendous efficiency for fibered networks. The aim of this work was to investigate the feasibility of their transposition to the case of satellite-to-ground optical links, accounting for their specificities: laser phase noise, Doppler effect, and the impact of propagation through the turbulent atmosphere and its correction by adaptive optics. We investigated for different turbulence conditions two architectures of digital receiver: one based on a phase-locked loop, and the other one based on an open loop approach. As expected, the importance of the quality of the adaptive optics correction is highlighted. This work opens prospects for a strong increase in the achievable bit rate for coherent telemetry links when using higher-order constellations (QPSK and beyond).