Satellite orbit determination using quantum correlation technology

Yanghe Shen, Luping Xu, Hua Zhang +2 more

朱俊 Zhu Jun, 陈霄祥 CHEN Xiao-xiang, 曾贵华 Zeng Guihua

Costantino Agnesi, Luca Calderaro, Daniele Dequal +7 more

Satellite quantum communications have rapidly evolved in the past few years, culminating in the proposal, development, and deployment of satellite missions dedicated to quantum key distribution and the realization of fundamental tests of quantum mechanics in space. However, in comparison with the more mature technology based on fiber optics, several challenges are still open, such as the capability of detecting, with high temporal accuracy, single photons coming from orbiting terminals. Satellite laser ranging, commonly used to estimate satellite distance, could also be exploited to overcome this challenge. For example, high repetition rates and a low background noise can be obtained by determining the time-of-flight of faint laser pulses that are retro-reflected by geodynamics satellites and then detected on Earth at the single-photon level. Here we report an experiment with regard to achieving a temporal accuracy of approximately 230 ps in the detection of an optical signal of few photons per pulse reflected by satellites in medium Earth orbit, at a distance exceeding 7500 km, by using commercially available detectors. Lastly, the performance of the Matera Laser Ranging Observatory is evaluated in terms of the detection rate and the signal-to-noise ratio for satellite quantum communications.

Daniele Dequal, Luis Trigo Vidarte, Victor Roman Rodriguez +4 more

Abstract Establishing secure communication links at a global scale is a major potential application of quantum information science but also extremely challenging for the underlying technology. Although milestone experiments using satellite-to-ground links and exploiting singe-photon encoding for implementing quantum key distribution have shown recently that this goal is achievable, it is still necessary to further investigate practical solutions compatible with classical optical communication systems. Here, we examine the feasibility of establishing secret keys in a satellite-to-ground downlink configuration using continuous-variable encoding, which can be implemented using standard telecommunication components certified for space environment and able to operate at high symbol rates. Considering a realistic channel model and state-of-the-art technology, and exploiting an orbit subdivision technique for mitigating fluctuations in the transmission efficiency, we find positive secret key rates for a low-Earth-orbit scenario, whereas finite-size effects can be a limiting factor for higher orbits. Our analysis determines regions of values for important experimental parameters where secret key exchange is possible and can be used as a guideline for experimental efforts in this direction.

Wei Fan

C. Barbieri, Gianfranco Cariolaro, Tommaso Occhipinti +3 more

The purpose of this project is to improve the techniques of Quantum Cryptography, to realize a Quantum Key Distribution (QKD) in free space with an orbiting satellite using nowadays technology. With this experiment we characterize the properties of a single photon communication channel from an orbiting satellite in space to a ground based station. We used the facilities of the ASI laser ranging station MLRO (Matera) and the satellite for geodesy Lageos I, equipped with corner-cube retroreflectors, to simulate a single photon transmission from an orbiting satellite.