Open AccessOptimized smoothing of Gravity Recovery and Climate Experiment (GRACE) time‐variable gravity observations
Author(s) -
Chen J. L.,
Wilson C. R.,
Seo K.W.
Publication year - 2006
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005jb004064
Subject(s) - smoothing , noise (video) , residual , gaussian noise , geodesy , gaussian , environmental science , geology , meteorology , mathematics , statistics , computer science , algorithm , physics , quantum mechanics , artificial intelligence , image (mathematics)
High‐degree and high‐order spherical harmonics of time‐variable gravity fields observed by the Gravity Recovery and Climate Experiment (GRACE) gravity mission are dominated by noise. We develop two smoothing methods that suppress these high‐degree and high‐order errors with results superior to more commonly used Gaussian smoothing. These optimized smoothing methods considerably improve signal‐to‐noise levels of GRACE terrestrial water storage estimates relative to residual signal and noise over the oceans and show significantly better spatial resolution and lower leakage error. On the basis of analysis using an advanced land surface model, the equivalent spatial resolution from these optimized smoothing estimates is about 500 km, compared to the roughly 800–1000 km Gaussian smoothing that is required to suppress high‐degree noise in the GRACE fields.