时变重力场反演地表非潮汐负荷形变及其精度

Inversion of surface non-tidal load deformation by using time-varying gravity field and its accuracy

针对高频噪声、条带噪声和信号泄露的问题,该文利用DDK5去相关平滑滤波和逆高斯滤波方法处理GRACE月时变地球重力场数据。由于不同机构月时变地球重力场精度不同,该文首先推导出地表非潮汐负荷形变精度计算公式,并计算4种产品精度,总体上从高到低依次为GFZ、CSR、ITSG、JPL。另外,该文还将GRACE反演的地表非潮汐负荷形变与158个IGS站计算结果进行比较,计算两者相关性和一致性。结果表明:①有64%以上IGS站相关系数大于0.5,最高达到0.9,为BRAZ和HYDE站;②有84%以上IGS站存在一致性。总之,大部分IGS站GRACE与GNSS时间序列吻合较好,这说明利用GRACE重力卫星时间动态且空间连续地反演由于地表质量变化引起的非潮汐负荷形变具有一定的可行性。

To effectively solve the problems of high-frequency noise,stripe noise and signal leakage,DDK5de-correlation and smoothing filter and inverse Gaussian filter were used to process GRACE monthly time-varying Earth’s gravity field data products.The accuracy of the monthly time-varying Earth’s gravity field varies with different institutions,the formula for calculating the deformation accuracy of surface non-tidal load were derived,and the accuracy of four products was calculated,the results ranged from high to low is GFZ>CSR>ITSG>JPL.In addition,the surface non-tidal load deformation obtained by GRACE inversion was compared with the results of 158IGS stations,and the correlation and consistency between GRACE and GNSS was calculated.The results showed that:①the correlation coefficient of more than 64%IGS stations were greater than 0.5,highest reaching 0.9,which were station LHAZ and HYDE;②the consistency was found in more than 84%IGS stations.In conclusion,GRACE and GNSS time-series of most IGS stations were in good agreement,which showed the feasibility of using GRACE gravity satellite to invert non-tidal load deformation caused by surface mass change in a dynamic and continuous method.