Surface charging has been identified as the probable cause of anomalies experienced by several high-inclination, high-altitude spacecraft. These spacecrafts have no monitors of the local space particle environment. Thus, a direct association of anomaly occurrence with surface discharge is not possible. The authors use empirical magnetic-field models to map from a satellite’s position, at the time of an anomaly, to the Earth’s magnetospheric equatorial plane. They appeal to the well-established occurrence distribution of spacecraft charging in the near-geostationary orbit equatorial plane as a function of magnetic local time, radial distance, and geomagnetic activity to interpret the anomaly events. On the basis of the similarity between known surface charging distributions and the anomaly distributions, it is concluded that anomaly-associated surface charging likely occurred owing to transient hot plasma and medium-energy electrons associated with magnetospheric substorms. It is believed that this technique will aid satellite operators in the assessment of anomalies experience by high-inclination spacecraft
