Demonstration of Optical Clock-Free Localization and Navigation (CLAN)

Positioning, navigation, and timing (PNT) applications often rely on establishing synchronized clocks to achieve accurate localizations. The accuracy of the measurement is compromised due to clock drifts or inaccurate timing. In this manuscript, we propose and demonstrate autonomous optical clock-free localization and navigation (CLAN) system that eliminates the need for synchronized clocks and uses free-running lasers at the transmitter and receiver sites. Experimentally we show that a remote static or dynamic receiver >1.8 km away from the transmitter determines its relative location to the transmitter with a <1 cm uncertainty and successfully identifies >2 cm incremental changes in distance without using time information. The experimental results are also verified by theoretical modeling and numerical simulations. The proposed technology is proven to be suitable for long-range localizations, autonomous navigations, and timing distributions in GPS-denied environments.