Spectral Combination of Spherical Gradiometric Boundary-Value Problems: A Theoretical Study
2012 (English)In: Pure and Applied Geophysics, ISSN 0033-4553, E-ISSN 1420-9136, Vol. 169, no 12, 2201-2215 p.Article in journal (Refereed) Published
The Earth's gravity potential can be determined from its second-order partial derivatives using the spherical gradiometric boundary-value problems which have three integral solutions. The problem of merging these solutions by spectral combination is the main subject of this paper. Integral estimators of biased- and unbiased-types are presented for recovering the disturbing gravity potential from gravity gradients. It is shown that only kernels of the biased-type integral estimators are suitable for simultaneous downward continuation and combination of gravity gradients. Numerical results show insignificant practical difference between the biased and unbiased estimators at sea level and the contribution of far-zone gravity gradients remains significant for integration. These contributions depend on the noise level of the gravity gradients at higher levels than sea. In the cases of combining the gravity gradients, contaminated with Gaussian noise, at sea and 250 km levels the errors of the estimated geoid heights are about 10 and 3 times smaller than those obtained by each integral.
Place, publisher, year, edition, pages
2012. Vol. 169, no 12, 2201-2215 p.
Biased and unbiased estimators, gravity gradients, spectral coefficients, tensor spherical harmonics, downward continuation, optimal solution
IdentifiersURN: urn:nbn:se:kth:diva-109177DOI: 10.1007/s00024-012-0504-6ISI: 000311404200010ScopusID: 2-s2.0-84869743095OAI: oai:DiVA.org:kth-109177DiVA: diva2:582793
QC 201301072013-01-072012-12-212013-01-07Bibliographically approved