基于小波变换的CORS站坐标时间序列周期性分析

Periodical Analysis on CORS Coordinate Series Based on Wavelet Transform

获取CORS站坐标时间序列的周期性变化,掌握其周期性变化特征,对分析CORS站坐标变化规律及速度估算具有重要作用。本文利用小波分析对国内北京、拉萨、乌鲁木齐三个具有区域代表性的CORS站进行周期性分析。以coifs3作为小波基计算三个站各方向分量的小波方差,获取其主要周期的尺度,并针对每个主周期尺度进行周期性分析。分析结果表明CORS站坐标具有明显的半年性周期特性,但因地域不同又表现出一定的差异性。另外,较水平方向,GPS高程观测更易受到噪声影响。

Achievement of the periodical changing character from coordinate series of CORS stations is very important for the changing regularity analysis and velocity estimation.In this paper,the wavelet analysis is presented for periodical analysis of the coordinate series of BJFS,LHAS,URUM stations.The scales of their primary period for the east,north and up directions of the three stations are obtained by selecting coifs3 as the base wavelet,and the wavelet variance is also calculated.Furthermore,periodical analysis is conducted for each of the primary period.The results show,The coordinates of CORS have obvious semi-annual periodic characteristics,but they show certain differences due to different regions.In addition,GPS elevation observations are more susceptible to noise than horizontal directions.