Open AccessGravity‐enhanced representation of measured geoid undulations using equivalent sources
Author(s) -
Guspí Fernando,
Introcaso Antonio,
Introcaso Beatriz
Publication year - 2004
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2004.02364.x
Subject(s) - geoid , geodesy , gravity anomaly , geology , undulation of the geoid , free air gravity anomaly , elevation (ballistics) , anomaly (physics) , geophysics , bouguer anomaly , geometry , physics , mathematics , paleontology , condensed matter physics , oil field , measured depth
SUMMARY Direct Global Positioning System measurement of geoid undulations on accurately levelled stations, usually tens of kilometres apart, can be interpolated by taking advantage of denser surveys of free‐air gravity anomalies covering the same area. Using either a spherical or a planar earth model, a two‐layer equivalent source is constructed, with the deepest masses located under the geoid stations and the shallower ones under the gravity stations, in such a way that the effect of the masses fits simultaneously, with different precisions, the anomalous potential related to the geoid and its vertical gradient or gravity anomaly. This poses a linear Bayesian problem, whose associated system of equations can be solved directly or by iterative procedures. The ability of the described method to predict the geoid elevation over the gravity stations is assessed in a synthetic example; and in the application to a real case, a gravity‐enhanced geoid is mapped for an area of Buenos Aires province, Argentina, where local features are put in evidence.