GNSS Reception at the Moon: First Results of the Lunar GNSS Receiver Experiment (LuGRE)

<title>Abstract</title> This article presents a comprehensive overview of the successful execution of the Lunar GNSS Receiver Experiment (LuGRE), the first known demonstration of global navigation satellite system (GNSS) signal acquisition, tracking, and navigation near and on the Moon. A general overview of the mission, payload, and ground system is provided. The as-flown mission profile is described in detail across the Earth–Moon transit, low lunar orbit, and lunar surface phases. A description of the high-level results of the mission is presented, including an evaluation of <italic>C</italic>/<italic>N</italic>₀, the quality of the pseudorange and carrier-phase measurements, the signal availability, the results of real-time least-squares position, velocity, and time estimation by the onboard receiver, and an evaluation of the in-phase and quadrature samples captured during the mission. Finally, key observations for future lunar GNSS users are discussed. The article also serves as a reference guide to the unique open data set released by the project.