重力固体潮信号的独立成分分析与谱相关解调

Independent component analysis of gravity earth tide signals and cyclic spectrum

针对提取重力固体潮潮汐谐波分量,分析各谐波分量间调制关系的问题,该文结合重力固体潮的产生机制建立了一种重力固体潮信号正交分解模型。利用独立分量分析算法和谱相关方法,分离出与模型相对应的独立分量信号,并从独立成分中解调出载波分量和被调制分量。从而完整地描述了地球自转产生的潮汐谐波与月球、太阳相对于地球轨道变化产生的潮汐谐波的正交分解关系。实验表明,此方法能有效地提取出重力固体潮信号中所包含的潮汐谐波信息,并揭示出该重力固体潮信号中存在3个线性叠加的独立分量,在月波分量和年波分量都以乘性调制的方式调制到半日波分量和日波分量上。

According to the problems of extracting the tidal harmonic components of gravity tide,and analyzing the relationship between the harmonic components,in this paper,an orthogonal decomposition model of gravity tidal signals was established.On this basis,Independent component signals corresponding to the model were separated by independent component analysis(ICA)algorithm.Because the independent component signal is the FM-AM components,by the cyclic spectrum analysis,the carrier component and the modulated component were obtained,and the multiplicative demodulation of the signal is realized.By using this method,the relation between the independent components of gravity tide signal and the gravity tide effects from the orbit position change of earth,moon and sun was described.The result showed that abundant tidal harmonic information could be extracted from gravity tide signal,and there were three independent components of linear superposition in gravity tide signal,and wave month and wave year were modulated in the diurnal waves and semidiurnal waves.