Prediction of gravity anomalies for geophysical exploration

Abstract

Interpretation of gravity anomalies (determined on the earth’s surface) reveals information on mineral resources beneath the earth. The density of gravity stations (where gravity anomalies are determined) is critical to the successful interpretation
of these anomalies. Where the density of the available gravity anomalies is not enough, for a particular purpose of geophysical exploration, more gravity stations can be established within the surveyed area and the gravity anomalies observed for these stations. In some cases, where observations of gravity anomalies are not possible due, probably, to inaccessibility of the newly chosen gravity stations, the required gravity anomalies for such stations can be estimated (predicted).
Currently, classical least squares technique is used to accomplish such task. However, the technique does not produce optimum results because its formulation assumes that the observed gravity anomalies, used for the prediction, are error free, whereas, all observed quantities are affected by random errors. Therefore, in this study, an attempt is made to carry out prediction of gravity anomalies for geophysical exploration using least squares collocation technique. This is
considered to be a better alternative because its formulation takes the presence of random errors of observations in the observed quantities into consideration and makes provision for filtering out these errors while predicting the signals of interest
at the required number of stations.