The Spatial Different Order Derivative Method of Gravity and Magnetic Anomalies for Source Distribution Inversion

Abstract

Gravity and magnetic measurements are common remote sensing strategies to obtain the property change of observed targets. Nowadays, the characteristic value of the derivatives of gravity and magnetic anomalies is commonly used to detect the source horizontal edge. We found that the horizontal coordinates of the characteristic value of different-order derivatives are not directly corresponding to the edge of the source, which varies with the depth and size of the source. The spatial different-order derivative (SDD) method of gravity and magnetic anomalies was developed, and we proved that the spatial intersection of different-order derivatives is corresponding to the location of the source, and used this feature to obtain horizontal location and depth of the source simultaneously. The model tests proved that the SDD method has high accuracy and strong anti-noisy. According to the corresponding relationship between the potential field data and lithology, we used the SDD method to delineate the potential metalorganic area in the survey region, which provides the basis for subsequent exploration.

Identifying the geological structure of the Garyan area in northwest Libya using eigen-6c4 satellite gravity data

“…The method assumes that the sources are approximated as two-dimensional structures. The TDR is a technique used to discriminate between gravity anomalies by analyzing their derivatives, which are vertical and horizontal derivatives (Ming et al, 2021). When the TAD value is positive, it shows a positive contrast with the underlying causative source, whereas when it is negative, it indicates that it is outside the limits of the source.…”

Delineating structure elements and depth of sources using an aeromagnetic data set in the Tarhona region, Nortwest Libya

“…The tiltangle method was utilised to sharpen and enhance the magnetic anomalies. Using a set of horizontal and vertical derivatives of the magnetic field, a tilt angle derivative is performed to distinguish between these two types of anomalies (Ming et al, 2021). When the TDR value is positive, it shows a positive contrast with the underlying causative source, whereas when it is negative, it indicates that it is outside the limits of the source.…”