Application of wavelets for along-track multi-resolution analysis of GOCE SGG data

Abstract

Due to limitations of the gradiometer the GOCE satellite gravity gradients (SGG) require filtering outside the measurement bandwidth. Several methodologies have been proposed and in use within the GOCE processing centre to filter the along-track data in the frequency domain. In this study we investigate the utilization of the localization properties of wavelets in both the frequency and space domains to decompose, analyze and reconstruct the gravity field signal in the SGG data at the different levels of a Wavelet Multi-resolution Analysis (WMRA). This approach can also be used to identify and eliminate temporally and spatially correlated errors in GOCE SGG data. The WMRA is applied in both the rotation of SGGs from the gradiometer reference frame to a local north orientated frame and in the downward (upward) continuation of the SGG tensor to a mean orbital height. Results presented here show that, at the GOCE mean orbital height, the MWRA has the potential to enhance the short-wavelength gravitational signal content of the along-track GOCE data.