FY-2卫星特殊事件对云图接收数量和质量的影响

Impact of FY-2 Satellite Special Events on Quantity and Quality of Cloud Images

以FY-2E卫星为例,利用2010年1月至2013年12月国家卫星气象中心积累的业务运行数据,统计分析了4年中由特殊事件造成无法接收或无法处理的云图数量、所占比例以及受影响云图的时间分布;从发生机理、规律和对卫星云图的影响程度分析了特殊事件;提出了改进建议。结果表明:受特殊事件影响的卫星云图数约占计划接收云图数的2.82%。特殊事件对云图的影响程度由大到小依次是:地影,轨道与姿态控制,日凌,月亮、太阳像与杂散光干扰,消旋失锁,月影;所影响云图数比例分别是:94.00%、2.82%、1.41%、0.67%、0.59%、0.52%;受影响云图数约97%分布在2-4月和8-10月,这是因为地影、日凌和太阳像干扰基本发生在每年的春分和秋分前后,其他特殊事件的发生与季节、节气关系不大。为减小特殊事件对卫星云图的影响,地面应用系统需根据地影预报时间制定更精确的云图计划接收表,合理选择轨道和姿态控制时间;卫星需进一步改进光学系统、电子器件的设计和工艺等。

Taking FY-2Esatellite as an example,the operation data accumulated by NSMC from January2010 to December 2013 are studied to analyze the number,proportion and time distribution of the cloud images affected by the special events.The mechanism,occurrence regularity and impact of the special events on cloud images are analyzed,and suggestions for improvement are put forward accordingly to reduce the impact of special events.The results show that the number of cloud images affected by special events accounts for 2.82 percent of the planned number of received images,and the sequence of the impact of special events on cloud images is：earth shadow,station keeping and attitude determination,sun transit outage,lunar,solar image and stray radiation interference,losing lock of antenna,and lunar shadow.The respective percentages of cloud images affected by these special events are：94.00%,2.82%,1.41%,0.67%,0.59%,and 0.52% approximately.About 97% of the affected cloud images are distributed between February to April and August to October,because earth shadow,sun transit outage,and solar image interference occurs before or after the vernal equinox and autumnal equinox each year,and the other special events have no relation with seasons and solar terms.In order to reduce the impact of special events,ground systems should make more accurate cloud image observation plans based on the prediction time of earth shadow and choose reasonably orbital station keeping and attitude determination time.FY-2satellites should improve the design and technology of optical system and electronic devices.