Variogram analysis of magnetic and gravity data

Model variograms describe the space domain statistics of magnetic and gravity data. Variogram analysis can be used to map intensity, depth, and scaling exponent (self-correlation) of source. Ln previous statistical methods the measured data were gridded and transformed to the wavenumber domain; then their power spectrum was analyzed using a spectral model. To avoid the loss and distortion of information during gridding and wavenumber domain transform, I transform the spectral model to the space domain instead. Variograms are the appropriate space domain counterparts of magnetic and gravity power spectra. The variogram of the field above a selfsimilar half-space model is governed by three parameters: intensity, depth, and scaling exponent. These source parameters can be mapped with high resolution and accuracy by fitting model variograms directly to magnetic and gravity line data variograms.