Quantum Metrology: Elevating Precision and Security in PNT

Last Updated: 06/06/2023 06:49     Created at: 06/06/2023 06:46

Final Presentation of NAVISP Project EL1 041 now available:
On Thursday, May 25th, 2023, GMV NSL Ltd presented the results of the NAVISP EL1 041 project "Quantum Metrology for Secure PNT". Over 30 people from industry and research institutes followed the interesting presentation and the subsequent interactive Q&A session.

Quantum metrology techniques have revolutionized Positioning, Navigation, and Timing (PNT) by offering remarkable precision and heightened security. These techniques leverage the unique properties of quantum states of light and matter, surpassing classical limitations imposed by classical mechanics. By leveraging entangled photons' timing correlations, precise ranging and clock synchronization can be achieved, exhibiting significant improvement over classical time-of-flight protocols. These protocols have shown resilience against jamming attempts and have effectively prevented spoofing attacks through the exchange of quantum signals. Additionally, a proposed quantum clock synchronization protocol ensures security against passive and active photon delay attacks, safeguarding critical PNT systems.

To address the limitations of existing positioning and timing quantum metrology techniques, this project aims to develop technologies for free-space PNT systems, specifically for mobile and space environments. The project involves creating a functional free-space quantum metrology system with a comprehensive analysis of precision, noise sources, and security aspects. Furthermore, it provides a roadmap for implementing the system in various PNT applications, including space deployment. The prototype system architecture consists of a transmitter and a receiver subsystem. The transmitter generates quantum pseudorandom noise (PRN) using the polarization of light, while the receiver includes a clock signal generator, laser driver, multiplexor, attenuator, telescopes for maximizing photon reception, and photon detectors. Two computers control the system and process data obtained from the photon counter to compute correlations and quantum bit error rates (QBER). Additionally, the system incorporates White Rabbit (WR) switches for precise time transfer over fibre optics, ensuring accurate synchronization between different components. A time interval counter further enhances time transfer accuracy by precisely measuring clock differences.

The project's potential future technological roadmap spans three phases. Phase 1 focuses on establishing permanent fix stations with two-way time transfer capability. These stations, strategically selected with a minimum distance of 10km, require adequate indoor facilities and automatic alignment systems for precise synchronization. Phase 2 involves developing a mobile station, enabling flexible operation in different locations, such as utilizing drones. Extensive studies will be conducted to evaluate system performance under various conditions and perturbations. Finally, Phase 3 entails transitioning to a satellite-based infrastructure, deploying the system on a Low Earth Orbit (LEO) satellite dedicated to PNT applications. Further research will address the effects of atmospheric conditions, movement dynamics, relativistic effects, and other relevant factors in space environments. 

The project was carried out in the scope of NAVISP Element 1, which is dedicated to technology innovation of the European industry in the wide PNT sector.
More detailed information can be found in the slides of the Final Presentation.