FY-3A卫星与NOAA系列卫星高能带电粒子实测结果的比较

FY-3A卫星是运行于830 km高度的太阳同步轨道气象卫星, 其搭载的空间环境监测器可观测3~300 MeV的高能质子和0.15~5.70 MeV的高能电子. FY-3A卫星在轨工作期间, 太阳活动处于由谷年向峰年过渡期, 空间环境非常平静, 探测结果显示3~300 MeV的高能质子分布主要集中在南大西洋辐射带异常区, 0.15~5.70 MeV的高能电子分布区域除南大西洋异常区外, 还分布在南北两极高纬区域. FY-3A与NOAA卫星测量结果反映出带电粒子强度及分布区域随投掷角变化的空间各向异性特征. 本文在充分考虑了带电粒子时间、空间分布差异以及比对探测器之间自身设计差异的前提下, 经过归一化处理后, 首次对两颗卫星同期探测结果进行相关性分析, 验证了两颗卫星相同时空条件下高能带电粒子通量分布的一致性; 说明FY-3A空间环境监测器不仅具备空间带电粒子辐射监测能力, 且探测结果有效可靠, 可用作辐射带环境数据源的组成部分, 为发展新的模型, 深入研究辐射带高能粒子的分布、起源和传输等提供新的观测依据.

Comparison of High Energy Particles Observation Results Between FY-3A Satellite and NOAA Series Satellites

FY-3A satellite was launched in June 2008 into solar synchronization orbit (about 800 km altitude). There are detectors that can measure 3~300 MeV high energy proton and 0.15~5.70 MeV high energy electrons on FY-3A satellite to carry out long-time space particles environment measurement. During the period from 2008 to 2009, space environment is very quiet because of low solar activities. The detection results on FY-3A satellite shows that flux of 3$sim$300,MeV high energy protons mainly are confined to SAA, whereas flux of electrons are located in SAA and around the north and south poles. The result also shows that the flux of energetic particles is to be highly anisotropic. By combining the detection result from FY-3A satellite with that from NOAA satellites, we can also find there exit differences between the detecting data from the two series of satellites not only in the space distribution of particles but also in the intensity of particles. These show the flux of energetic particles is to be highly anisotropic influenced by different pitch angles. Considering the difference of the particles flux and distribution induced by limits of time and space, even and the different designs between the detectors on the two satellites, we compared the protons and electrons detection results from FY-3A with those from NOAA satellites. A generally good agreement is observed in the flux values and distribution trend of protons and electrons. All the above indicates the detectors on FY-3A satellite have the ability to measure space energy particles. The detection results are now available, so that we can use the data from FY-3A satellite to further study radiation belt particles distribution, origin and transmission.