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...

precise geoid determination on islands suffers from the lack of accurate gravity data on the open seas. nowadays, sub-microgal accuracy for the land gravity observations is obtainable. but the sea gravity data which are collected via shipborne techniques, due to the measuring environment at sea area, are usually highly noisy and are contaminated with various systematic errors. on the other hand...

Gravity data inversion is one of the important steps in the interpretation of practical gravity data. The inversion result can be obtained by minimization of the Tikhonov objective function. The determination of an optimal regularization parameter is highly important in the gravity data inversion. In this work, an attempt was made to use the active constrain balancing (ACB) method to select the...

we inverse the surface gravity data to recover subsurface 3d density distribution with two strategy. in the first strategy, we assumed wide density model bound for inverting gravity data and in the second strategy, the inversion procedure have been carried out by limited bound density. wediscretize the earth model into rectangular cells of constant andunidentified density. the number of cells i...

The 3D correlation imaging for gravity and gravity gradiometry data provides a rapid approach to the equivalent estimation of objective bodies with different density contrasts in the subsurface. The subsurface is divided into a 3D regular grid, and then a cross correlation between the observed data and the theoretical gravity anomaly due to a point mass source is calculated at each grid node. T...

â â â â â â â â â â â â  abstract: â  as a result of recent developments, global economic centre of gravity has slide to asia-pacific region. it is predicted that asia-pacific countries will take place at the first row in global trade and nearly a half of the total trade will intensify in this region at the year 2030. on the other hand, the region covers countries from different levels of devel...

Detection of subsurface structures by means of gravity method can be used to determine mass distribution and density contrast of rock units. This distribution could be detected by different geophysical methods, especially gravity method. However, gravity techniques have some drawbacks and can't be always successful in distinguishing subsurface structures. Performance of the gravity technique co...

GOCE gravity fields define a new standard concerning spectral resolution of satellite-only models, and provide a very high precision in the longand medium wavelength part of the gravity field up to a spherical harmonic degree of about 250. Combining GOCE with GRACE data, which gives in addition very accurate information for the long wavelength part, results in the current performance status of ...