Windowed least-squares spectral analysis of grace k-band range rate measurements

Abstract

The objective of this manuscript is to utilize windowed least-squares spectral analysis for extracting the frequency contents of GRACE K-band range rate time series related to Iran’s main catchments. The spectral behavior of the unequally spaced time series affected by satellites and Earth rotations should be studied using the Least-Squares Spectral Analysis due to the inherent limitations in the traditional Fourier and Wavelet Transformations techniques. We explain the principles of windowed least squares spectral analysis as an alternative method of the Least-Squares Spectral Analysis in order to access a timefrequency representation of irregularly sampled GRACE range rate time series related to Iran’s main catchments. The results are in good agreement with the spectral behavior of the total water storage changes modeled in the catchments, as well as with the previous research findings.