A Catalogue of Dispersive GNSS Occultation Arcs Observed by LuGRE Along the Blue Ghost Mission 1 Trajectory

The Lunar GNSS Receiver Experiment (LuGRE), hosted onboard the Blue Ghost Mission 1 mission, provided the first opportunity to observe Global Navigation Satellite System (GNSS) signals throughout the cislunar space volume and from the lunar surface. Due to the unique Earth–Moon geometry, a significant fraction of the received signals propagated through the Earth’s ionosphere and plasmasphere, enabling the observation of long-duration dispersive occultation arcs over extended altitude ranges. This work presents the methodology leading to a first catalogue of dispersive GNSS occultation arcs observed during the LuGREoperations. Adedicated processing pipeline was developed to automatically identify and classify ionospheric crossings using only dual-frequency GPS and Galileo observables available in the mission dataset. The methodology exploits Slant Total Electron Content (STEC), Rate of TEC (ROT), and Rate of TEC Index (ROTI) measurements to detect and classify arcs as ingress, egress, or tangent arcs. Identification and classification results are independently validated through a geometry based analysis of the line-of-sight grazing altitude. Application of the proposed approach to all LuGRE scientific operations led to the identification of 229 dispersive arcs, achieving a classification agreement of 95.6% with respect to the geometric reference. The resulting catalogue provides arc timing, duration, geometric characteristics, and ionospheric indicators derived from the GNSS observables. The analysis shows that many arcs probe the topside ionosphere and plasmasphere at altitudes extending well beyond those typically sampled by Low Earth Orbit radio-occultation missions. Furthermore, the majority of the detected arcs were observed from the lunar surface, highlighting the Moon’s potential as a stable platform for Earth observation and space-weather monitoring. The catalogue represents a new resource for studying the terrestrial plasma environment from cislunar space and supports future scientific exploitation of GNSS signals beyond Earth orbit.