A Robust Adaptive High-Precision Entangled Photons-Based Ranging System

Recently, ranging has played an increasingly important role in many scenarios, but the problems of limited security and accuracy have always been troubling. The entanglement ranging method provides picosecond-level clock synchronization and unconditional security and is deemed a good solution to meet the growing demand for accuracy and security, promising to play a significant role in the next generation of navigation. This paper focuses on the ranging system based on entangled photons, and proposes solutions to the challenges of accuracy and robustness. Specifically, a coincidence counting calibration algorithm is proposed to suppress the background noise, and a novel data selection algorithm based on relative quantum efficiency is proposed to suppress abnormal coincidence counting. Then, to improve the ranging accuracy even in challenging scenarios, the paper proposed a novel density-based hierarchical filtering algorithm to detect and filter outliers, resulting in more precise and reliable ranging. Finally, extensive experiments are carried out on the built test platform to verify the safety and effectiveness of the proposed system. The results show that the ranging error is 0.0225 m in the test time of 1 ns. The proposed algorithm reduced the ranging error of abnormal data from 1.5205 m to 0.0100 m, and achieved the probability (90%) of ranging error within 0.0150 m.