南极半岛地区GPS坐标时间序列噪声分析及形变模式初探

有色噪声广泛存在于各种连续GPS站坐标时间序列,对GPS时间序列分析有重要影响.利用GAMIT/GLOBK软件解算了南极半岛地区8个GPS测站2010—2014年的实测数据,对坐标时间序列使用主分量分析法(PCA)进行了空间滤波,利用CATS软件估计了不同噪声模型下和空间滤波前后的噪声量级、站坐标时间序列参数及其不确定度,最后对南极半岛地区水平和垂向的形变模式进行了分析和讨论.结果表明,南极半岛地区GPS时间序列不仅存在白噪声,还存在较大量级的闪烁噪声,部分测站E方向在滤波前可能存在随机游走噪声;空间滤波能够有效降低这三种噪声的量级,从而有效减小线性项和周期项估计的不确定度;南极半岛地区在水平方向主要表现为板块运动,还可能存在局部性构造运动;在垂直方向上由冰川均衡调整(Glacial Isostatic Adjustment,GIA)因素引起的抬升较小,主要表现为现今冰雪质量损失引起的弹性抬升运动.

Noise analysis of the coordinate time series of the continuous GPS station and the deformation patterns in the Antarctic Peninsula

The colored noise is widely existed in various continuous GPS station coordinate time series, which has an important influence on GPS time series analysis. The measured data of 8 GPS stations in the Antarctic Peninsula area was solved by GAMIT/GLOBK software and principal component analysis (PCA) method was used in spatial filtering of the GPS time series. CATS software was used to estimate and analyze the magnitude of noise, the parameters of GPS time series and the uncertainty of them. Finally, the horizontal and vertical deformation patterns of the Antarctic Peninsula are analyzed and discussed. The results show that not only white noise, but also large magnitude of flicker noise and possible random walk noise exist in Antarctic Peninsula GPS time series. Spatial filtering can effectively reduce the magnitude of white noise, flicker noise and random walk noise, so the uncertainty of the linear term and periodic term can be effectively reduced. The horizontal movement in Antarctic Peninsula area is mainly expressed as plate movement and local tectonic movement may also exist. The uplift of glacial isostatic adjustment (GIA) is too small to be dominant movement and the vertical movement is mainly expressed as the elastic uplift movement caused by the loss of the current ice and snow mass.