Computer systems onboard FORMOSAT-2 (F2) and FORMOSAT-3/COSMIC (F3/C) satellites often register abnormal signatures which are recorded as automatic reconfiguration orders (ARO) in F2, and reboot/reset (RBS) in F3/C. The ARO and RBS spatial distribution counts recorded since the launch of satellites is investigated to identify regions of anomalous events. Data from the star tracker onboard F2 and Tiny Ionosphere Photometer (TIP) onboard F3/C are also analyzed. The results show that the F2 ARO and F3/C RBS cluster over the SAA (South Atlantic Anomaly) region and also over the poles, which suggest that high energy particles bombarding the satellite electronics play an important role.

Advances in semiconductor technology have enhanced the functionality of sensor arrays with reduced feature sizes. Owing to the spread of the Internet of Things, sensors can now be found in many applications operating in various environments. Proton and neutron radiation are always present around us but have not been detrimental to electronics at sea level. With the decreasing size of transistors and sensor elements and the increasing density of transistors in ICs of sensors and actuators, the effect of radiation on the reliability of semiconductor devices, sensors, and their electronic circuits (collectively called sensing systems) is no longer negligible, even at sea level. However, the knowledge of radiation physics and that of semiconductor physics are very different, and merging of the two sets of knowledge is necessary to evaluate the effect of radiation on the reliability of sensing systems. In this work, we summarize the extensive studies of the effects of radiation on semiconductor devices from space and avionics investigations, and we apply their results to study the radiation reliability of sensing systems in standard industry applications. In this work, we also illustrate how one can perform radiation reliability analysis for electronics in a proximity sensor, which we investigated by performing radiation experiments.

The variable electromagnetic environment in geospace plays a crucial role in influencing the occurrence probability of satellite anomalies. FORMOSAT-3 (FS3) is a Low-Earth-Orbit (LEO) mission, which consists of six identical microsatellites that orbit in the altitude of 700–800 km and with an inclination of 72°. The dependences of the FS3 satellite anomalies on space weather conditions have not been investigated in the past. With an exception of a small number of extremely high geomagnetic events, we find that the occurrence rate of the FS3 anomalies is negatively correlated with the level of geomagnetic activity. Moreover, the relationship between numbers of anomalies and sunspots is also anti-correlated. A superposed epoch analysis demonstrates that the intensity of galactic cosmic rays (GCR) is relatively high at the times of the anomalies. All these results infer that the FS3 anomalies predominantly occurred under the conditions associated with low solar activity. The possible main cause for the FS3 anomalies is high-energy trapped protons or GCR. In summary, this paper presents a statistical result that a satellite can be prone to suffer an anomaly under low solar or geomagnetic activity.