奇异谱分析在太阳10.7cm射电流量中期预测中的应用

首次尝试利用信号处理技术奇异谱分析方法预测太阳活动低年未来27天太阳10．7cm射电流量．选取的预报试验时间段是2004年4月30日至5月30日，此试验期内太阳活动水平相对较低．在样本时间序列的构建上，吸取了相似周数据分析思路，采取的是23周实时观测数据与其相似周第20周下降年部分数据相结合的方式，既增加了样本长度又避开了太阳活动的活跃期．这31天的预报试验结果表明，大部分情况下，预报值基本上体现出F10．7的变化趋势，平均相对误差为10．5％；比同时期美国空军预测值的平均相对误差小，前者为11．3％，后者为14．6％；除两天外，SSA每一次27天的预报结果的平均相对误差比美国空军(AAF)的要小；对不同的时间提前量而言，AAF提前1天到提前12天的预报准确性较奇异谱分析方法要高，即AAF较短期的预报效果更好．

Application of Singular Spectrum Analysis to Solar 10.7 cm Radio Flux 27-day Forecast

In this paper, singular spectrum analysis (SSA) method was applied to 27-day solar 10.7cm radio flux forecast for the first time. In order to focus on the F10.7 prediction during the period of the low level solar activity, the test prediction range was chosen from April 30 to May 30, 2004 within the cycle 23 descendent phase. To ensure there were enough data to construct the sample series, both real time data and partial data in the cycle 20 descendent periods following the rule of similar cycle method were chosen, in this way sampling number increased and at the same time, effects of high solar activity are kept away so to get more precise F10.7 forecast during the low solar activity. The forecasted results of these 31 days show that they mainly coincided with the general tendency of F10.7 vaviations. The averaged relative error of each 27-day forecast was about 10%. The total average relative error of the 31 days was 10.5%. The minimum average relative error was 4.8% and the maximum was 16.7% during the test forecast period. Comparing with American Air Force (AAF) forecast in the same periods, the total average relative error of SSA is less than AAF, the former was 11.3% and the latter was 14.6%. Furthermore, each average relative error of SSA was less than AAF except two days. But to the short-term forecast within one day to 12 days, the result of AAF was superior to SSA.