Catalog Releases 263 GNSS Occultation Arcs from Cislunar and Lunar Surface Observations

Researchers identified arcs using dual-frequency ROT and ROTI metrics combined with a geometric grazing-altitude check, classifying them as ingress, egress or tangent without separating ionospheric from plasmaspheric contributions. The dataset supplies leveled STEC time series, summary statistics, geomagnetic indices and tangent-point coordinates for each event, filling a gap between ground-based and LEO occultation records during the declining phase of solar cycle 25. It directly supports improved modeling of navigation-signal degradation for future lunar and cislunar missions.

The work complements existing ionospheric datasets by extending coverage to distances where plasmaspheric electron content dominates and where solar-cycle effects on trans-lunar links remain poorly sampled. Because instrumental biases remain uncorrected, users must apply external calibration before absolute TEC studies. The catalog's rapid-selection design enables targeted statistical analyses of space-weather impacts on GNSS performance beyond Earth orbit.

Limitations include the single combined dispersive signature per arc and the modest event count during one mission phase. Larger samples from follow-on payloads and cross-mission fusion would strengthen constraints on plasmaspheric variability and support real-time correction algorithms for Artemis-era navigation.