有色噪声对东南极区域GPS测站三维速度估计的影响

The Effect of Colored Noise on the Three Dimensional Velocity Estimations of GPS Stations in East Antarctica Region

近年来,有研究发现在GPS测站坐标时间序列中既存在白噪声,也存在有色噪声。为了研究有色噪声对东南极区域GPS测站三维速度估计的影响,本文使用GAMIT/GLOBK10.5软件对东南极区域6个连续GPS测站2005—2014年的实测数据进行解算和平差,并利用最大似然法(MLE)分别估计了在两种假设噪声模型条件下的测站三维运动速度及其不确定性。结果表明:在进行参数估计时,考虑两种有色噪声(闪烁噪声和随机游走噪声)对东南极区域GPS测站三维速度估计的量级影响不大,水平方向最大影响量级为0.3 mm/a,垂直方向最大影响量级为0.8 mm/a;但如果不考虑有色噪声,会严重低估参数估计的真实不确定性。

In recent years, it has been found that there were both white noise and colored noise in the coordinate time series of GPS stations. In order to study the effect of colored noise on the three dimensional velocity estimations in East Antarctica region, the measured data of 6 GPS stations from 2005 to 2014 were used for solution and adjustment by GAMIT/GLOBK10.5 software, and the maximum likelihood method （MLE） was used to estimate the three dimensional velocities and errors of the GPS stations when two noise models were assumed. The results show that when two kinds of colored noise （flicker noise and random walk noise were considered） , the 3D velocity estimations of GPS stations in East Antarctica region have small changes, the maximum impact magnitude is 0.3 mm/a in horizontal and 0.8 mm/a in vertical. However if the colored noise was not considered, the parameter estimations of the true uncertainty would be seriously underestimated.