To the Moon: DAS measurements of anthropogenic signals in LUNA

Kurzfassung

The LUNA Moon analogue facility, jointly operated by DLR and ESA in Cologne, Germany, provides a simulated lunar environment for instrument and experiment tests and operations training for both robotic and crewed missions. At the heart of LUNA is a 700 m2 regolith testbed, filled to 60 cm depth with EAC-1A Mare simulant, which also contains a deep-floor area with of to 3 m depth. Before filling the hall with the regolith simulant, a 500 m long fiber-optic cable containing single- and multi-mode fibers, as well as an engineered fiber, was deployed in a spatial grid to support future tests of DAS and DTS applications for the Moon. The first user campaign after inauguration of LUNA collected 4 days of DAS data in November 2024, partly overlapping with a test of vertical-component geophones for a possible Artemis IV deployed instrument. Besides, a preliminary set-up of the LUNA broad-band station (Trillium Compact 120 s) was recording continuously at the same time. In this presentation, we show results for geolocating and mapping the fiber in LUNA (using tap test, weight drops, and QGIS) and compare the characteristics of signals recorded by the different instruments. We investigated and describe hammer shots for geophone-based refraction seismics, signals from cars, airplane take-offs (from nearby CGN airport), a helicopter overfly (with characteristic Doppler shift), the crane within LUNA, and a small, 3U-cubesat sized rover driving in LUNA. We also recorded a teleseismic earthquake with the DAS. Our results provide a comprehensive baseline characterization of anthropogenic noise at our facility, offering a valuable reference for identifying external events at LUNA during future user campaigns and mission preparations.