基于快速傅里叶变换与小波变换的GNSS坐标时序时空演化特征分析  

Temporal and Spatial Evolution of GNSS Coordinates based on FFT and Wavelet Transform

作　　者：尚军 南凯麒 王明洋 SHANG Jun;NAN Kaiqi;WANG Mingyang(School of Geology and Geomatics,TCU,Tianjin 300384,China)

机构地区：[1]天津城建大学地质与测绘学院,天津300384

出　　处：《天津城建大学学报》2024年第6期410-418,共9页Journal of Tianjin Chengjian University

基　　金：天津市教委科研计划项目(2021ZD001)。

摘　　要：中国位于欧亚板块东南部,处于印度板块、太平洋板块和菲律宾海板块的挤压夹持之中,分布有广泛且复杂的地质构造,成为了地壳运动较强且较为复杂的地区.GNSS连续观测是获得地壳运动信息的重要来源,从GNSS坐标时序提取周期及趋势项可为分析区域地壳运动提供研究基础.本文综合利用快速傅里叶变换与小波变换方法开展中国大陆地区GNSS坐标时序时空演化特征分析.首先采用对GNSS坐标时序进行预处理和降噪处理,然后利用快速傅里叶变换方法在频域上对分区GNSS站点坐标时序进行周期提取,最后依据GNSS测站周期,利用小波变换方法进行分解与重构,获得高频周期项结果和低频趋势项结果,并开展相关分析.研究发现:①在1年以内的时间尺度上,除东北区域以外,各方向上的周期均以1年周期为主,半年周期次之,季节周期较弱;②各站点在N、E、U 3个方向上各年的一年、半年周期的周期长度均存在一定的伸长或收缩,不同区域的不同站点随时间呈现出的周期强度变化存在一定差异;③在研究时段内,中国大陆地区在水平方向上的地壳运动趋势为:中国西部呈现向东北偏移的趋势,其余区域呈现向东南偏移的趋势,且向东偏移的趋势略强于向南、北方向偏移的趋势.在垂直方向上,不同区域不同站点的运动趋势较为复杂.China lies in the southeast of the Eurasian plate,which is squeezed by the Indian plate,the Pacific plate and the Philippine Sea plate.Under the influence of the crustal movement,the widespread and complex geological structures were generated in the Chinese mainland,and it become a region with strong and complex crusts.The complex geological structure also makes the Chinese mainland become one of the regions with frequent earthquakes in the world.The frequent earthquake disasters caused great damage to people's production and daily life and had the effect on normal operation of society.As all over the world,the establishment and perfection of GNSS reference station network,GNSS technology is one of the main methods of crustal movement monitoring and analysis,the time series of GNSS coordinates provides important basic data for the research of the class.In this paper,the continuous observation stations of CMONOC in China's Mainland is selected to analyze the GNSS coordinate time series by Fourier transform and wavelet transform.Firstly,GNSS coordinate time series was prepossessed and denoised.Then the cycle of the GNSS coordinate time series was extra-cted and analyzed by using fast Fourier transform method in frequency domain.Finally,according to the period information,the coordinate time series is decomposed and reconstructed by wavelet transform,the results of high-frequency period term and low-frequency trend term are obtained,and the results are analyzed.The main conclusions of the study are as follows:On the whole,the periodicity in the vertical direction of Chinese mainland is stronger than that in the horizontal direction of the north direction and the east direction,and the periodicity intensity in the north direction and the east direction is similar.In the time scale of one year or less,except for the northeast region,the period of all parties is dominated by annual cycle,followed by semi-annual cycle, and the seasonal cycle is weak in the vertical direction. The annual and semi-annual cycles of each si

关 键 词：地壳运动 时频分析 GNSS坐标时间序列 快速傅里叶变换 小波变换 

分 类 号：P226.3[天文地球—大地测量学与测量工程]