Least-squares modification and satellite gravity gradiometry
2009 (English)Conference paper (Refereed)
Satellite gravity gradiometry is a technique to determine a precise high-resolution geopotential model based on spatial-differential accelerometry. The satellite gradiometric data plays an important role in this respect and they must be validated before doing any computation. One way of validating such a data is to use the second-order partial derivatives of the extended Stokes formula to generate the gradients at satellite level, from terrestrial gravimetric data. A global coverage of the terrestrial data is required to perform the integration, but having such coverage is neither practical nor reasonable, and the integrals should be modified. The integrals’ kernel is not isotropic (except for second-order radial derivative) and modification of such integrals will not be easy task. Here, general integral estimators for vertical-vertical, vertical-horizontal and horizontal-horizontal gradients are presented, based on combination of the gradients, so that that the estimators become modifiable. Least-squares modification minimizes not only the truncation error of the integral, but the errors of global gravitational model and the terrestrial data. Elements of the system of equations, from which the modification parameters based on biased, unbiased and optimum least-squares modification is derived, are mathematically formulated.
Place, publisher, year, edition, pages
spectral combination, validation, Paul’s coefficients, truncation error formula, ill-conditioning
IdentifiersURN: urn:nbn:se:kth:diva-63317OAI: oai:DiVA.org:kth-63317DiVA: diva2:481977
The VII Hotine-Marrusi Symposium. Rome, Italy. 6-10th July 2009
QC 201205072012-01-232012-01-232012-05-07Bibliographically approved