影响卫星故障的空间天气分析

基于美国国家地球物理数据中心(NGDC) 2384例和中国19颗卫星的263例卫星故障信息, 结合1963-2012年小时平均的多种空间环境数据, 定量分析了三种卫星故障发生期间的空间要素特征, 探讨单粒子锁定(SEU)、表面充电致静电放电(ESD)和内部深层充电所致电子引起的电磁脉冲(ECEMP)与空间天气事件的可能联系, 得出以下主要结论. (1)大部分SEU和ECEMP发生于空间天气平静时, 但在其前后3日内地磁活动达到了磁暴水平, 相对来说比例最大的发生在Dst_min之后第3日 (48～72h). (2) ESD受地磁活动和高能电子通量影响明显. 与磁暴、相对论电子通量增强事件的季节性相对应, 两分点附近ESD和ECEMP的发生率高; 93.6% 的 ESD发生前后72h内地磁活动达到磁暴水平, 故障发生时间均匀分布在 Dst_min前0～48h 和后0～24h; 54.9%的ESD 发生时处于地磁暴期(Dst <-30nT), 以-50～-30nT的小磁暴水平居多; 40.6%的ESD发生于高能电子通量高水平期(≥ 10³pfu, 1pfu =1cm^-2·s^-1·sr^-1), 81.9%的ESD发生前后72h 内高能电子通量峰值≥ 10³pfu, 发生率最高时段为电子通量峰值前 48～72h. (3)高能电子对中国同步轨道卫星的SEU影响明显, 42.5% 故障发生 时高能电子通量≥ 10³pfu, 故障在峰值前48～72h和峰值后48～72h 的发生概率相当, 约为23.0%. (4)同步轨道卫星SEU受太阳质子事件的影响相对较大, 22.5%的中国同步轨道卫星故障发生前后72h内发生了太阳质子事件, 季节性不明显.

Statistical Analysis of Space Weather Effects on Satellites Anomalies

Based on a large database of satellite anomalies containing 2384 anomalies from NGDC (USA) and 263 malfunctions from 19 satellites of China (CHN), and with a large set of hourly space weather condition parameters data over the period of 1963-2012, this paper quantifies statistically space weather conditions which may induce different spacecraft anomalies including Single Event Upset (SEU), Electrostatic Discharge (ESD) induced by surface charging, and Electron Caused Electromagnetic Pulse (ECEMP) resulting from internal, deep dielectric charging. The results are as follows. (1) Most anomalies of SEU, ECEMP occurred on quiet space conditions, whereas geomagnetic storms tended to happen during the 3 days (72h) before or after satellite anomalies started, and the most probable time for anomalies was on the third day (48～72h) after the minimum Dst (Dst_min). (2) Geomagnetic activities and high-energy electrons showed apparent effects on anomalies of ESD. Occurrence probabilities of ESD and ECEMP clearly increased in equinoxes (March, September), and such seasonal characteristic was consistent with that in occurrence probabilities of magnetic storms and Relativistic Electrons Flux Enhancement Events (REFEE). For 93.6% anomalies of ESD, geomagnetic storms tended to happen during 72h before, after ESD started, and the most probable occurring time was 0～48h before Dst_min or 0～24h after Dst_min. 54.9% anomalies occurred on geomagnetic conditions of Dst <-30nT, and intensities of storms seemingly influenced ESD little. 40.6% anomalies occurred at the time when the hourly >2MeV electron flux is above 10^3pfu (1pfu =1cm-2·s-1·sr-1). For 81.9% anomalies of ESD, the hourly maximum of high-energy electron flux, during 72h before or after ESD started, was above 10^3pfu, and the most probable time interval was 48～72h before electron flux maximum, when 33.3% anomalies occurred. (3) High-energy electrons showed apparent effects on SEU of GEO from CHN database, 42.5% of anomalies occurring on conditions of electron flux ≥ 103pfu. For those anomalies, the hourly maximum of > 2MeV electron flux exceeded 103pfu during 72h before or after which started. The anomaly occurrence probabilities at the time of 48～72h before and 48～72h after electron flux maximum, were comparative, being about 23.0%. (4) Solar Proton Event (SPE) showed more influence on SEU of GEO. SPEs seemed no regular seasonal variations based on data during 1975-2013, while occurrence probabilities of SEUs showed little seasonal dependence. For 22.0% SEUs of GEO from CHN database, SPEs occurred during 72h before or after anomalies started, and SEUs might occur at any time of the 72h before or after the maximum of >10MeV proton flux.