低轨道卫星表面电位探测器探测数据分析

目的 了解太阳活动低年低轨道卫星表面充电的特征规律,为今后低轨道卫星表面充电的防护设计提供参考.方法 利用我国一颗低轨道卫星搭载的表面电位探测器数据,对探测到的2017—2019年的78次表面充电事件进行统计分析.重点研究78次事件的充电时长、电位峰值、时空分布等特征以及事件与地磁活动的关系.结果 在太阳活动低年,83.3％表面充电事件持续时间不超过1 min,80.7％表面充电事件的充电峰值绝对值不超过100 V;97.4％的事件出现在南半球高纬度地区;88.5％的事件发生在磁地方时的18至02时之间;当表面充电事件发生率不为0时,事件发生率和Kp指数的相关系数为0.97.结论 在太阳活动低年,表面充电事件的持续时间较短,并且强度不大.表面充电事件发生位置具有明显的南北不对称性,呈现南多北少的趋势.表面充电事件多发生于高纬度地区,在磁地方时的傍晚至午夜发生概率高.表面充电事件发生率和地磁活动具有较好的相关性.

Analysis of Data from Surfacing Charging Detector on Board a LEO Satellite

In order to understand the characteristics of the surface charging of LEO satellites in solar minimum years, and provide reference for the protection and design of the surface charging of LEO satellites in the future. Based on the data of the surface charge detection carried by a LEO satellite in China, this paper studied 78 surface charge events from 2017 to 2019. The characteristics of charging duration, voltage peak, temporal and spatial distribution of 78 events, and the relationship between events and geomagnetic index were studied. The study found that 83.3% of the surface charging events lasted less than 1 min, and 80.7% of the surface charging events had an absolute peak charging value less than 100 V; 97.4% of the events occurred in the high latitudes of the southern hemisphere; 88.5% of the events occurred between 18~02 MLT; When the incidence rate of surface charging events is not 0, the correlation coefficient between the event incidence rate and the Kp index is 0.97. The results showed that in solar minimum years, the duration of surface charging events is short and the intensity is low. The location of the surface charging event has obvious north-south asymmetry, showing a trend of more in the south and less in the north. Surface charging events occur frequently in high latitudes, and the probability of occurrence is high from dusk to midnight in magnetic local time. The incidence of surface charging events has a good correlation with geomagnetic activity (as measured by the Kp index).