one of the main steps within the geoid computation methodology without applying the stokes formula is downward continuation of the harmonic residual observables from the surface of the earth down to the surface of the reference ellipsoid. this downward continuation is done via the abel-poisson integral and its derivatives. this integral in which the unknowns, i.e. harmonic residual potential va...

the normalized full gradient (nfg) method defined by berezkin (1967, 1973 and 1998) is used for downward continuation maps. analytical downward continuation is a method to estimate the field closer to the source and consequently results in a better resolution of underground rock distribution. however, the usefulness of this process is limited by the fact that the operation is extremely sensitiv...

linear filters are used for a wide range of magnetic science including noise attenuation, spatial derivatives, upward and downward continuation and reduction to the pole. the majority of these filters are spatially-invariant, meaning that the filter has a constant wave number response over the whole signal. in contrast, many signals which encountered real problems such as magnetic signals, typi...

$EVWUDFW With airborne gravimetry routinely reaching accuracies of 1-2 mGal at 5-10 km resolution, it is a challenge to perform a reliable downward continuation of the gravity anomalies at altitude. Airborne gravimetry is especially suited for geoid determination in mountainous and polar regions, due to the random, alias-free sampling of the terrain, relative to typical surface surveys. In the ...

Unlike many previous implementations of Kirchhoo-type waveeeld extrapolation (Berryhill, 1979; Bevc, 1995), we propose a procedure that is not only kinematically correct , but dynamically correct in heterogeneous media, in a model-consistent sense. Our approach is to specialize the general,\true-amplitude" data mapping platform of Bleistein & Jaramillo (1997) to the process of downward continua...

the problem of downward continuation of the gravity field from the earth’s surface to the reference ellipsoid arises from the fact that the solution to the boundary value problem for geoid determination without applying stokes formula is sought in terms of the disturbing potential on the ellipsoid but the disturbing gravity observations are only available on the earth’s surface. downward contin...