Beyond the Standard Quantum Limit in the Synchronization of Low-Earth-Orbit Satellites

Abstract

Quantum super-resolution involves resolving two sources below the Rayleigh limit using quantum optics. Such a technique would allow high-precision inter-satellite positioning and tracking on communication and navigation constellations. Due to the size, weight and power constraints typical of low-earth-orbit (LEO) satellites, a simple solution is often preferred. Here, we show that a balanced homodyne detection (BHD) setup using a shaped single-mode local oscillator can achieve super-resolution despite typical photonic losses. We further analyze the impact of a fluctuating and fixed centroid misalignment due to satellite pointing issues, and find that fixed misalignment is comparatively more detrimental to the performance of a BHD setup. Thus, our study provides a practical assessment of BHD to achieve super-resolution on a modern LEO satellite platform.

Quantum super-resolution with balanced homodyne detection in low-earth-orbit

“…where b1 is the LO annihilation operator in the HG 1,0 mode. The BHD measurement can be derived using the standard process outlined in our previous works [26,27]. For convenience of derivation, we can find the BHD measurement produced by each source separately.…”

“…Fortunately, the same issue is not expected over inter-satellite laser links due to shorter transmit-receiver range and more control over the source light. Particularly, in our first application of interest, low-earth-orbit (LEO) satellite networks, BHD is already gaining momentum as a technique for next-generation communications [24], clock synchronization [25][26][27] and laser ranging [28]. The analysis presented here shows that BHD may also enable high-precision positioning and navigation on future LEO satellite constellations.…”