Innovation In Geophysical Gridding Techniques: Intrepid Perspective

Abstract

A wide variety of numerical procedures in potential field geophysics require data modelled on a regular grid. However, airborne data tend to be highly sampled along the flight line and sparsely sampled in the perpendicular direction, A gridding method commonly called ‘bi-cubic spline’ is widely used in potential field geophysics. Standard bi-cubic spline methods used on aeromagnetic data produce artefacts when a geological feature’s ‘line of strike’ is not perpendicular to the direction of the acquisition line. This method has a tendency to break up thin elongated magnetic anomalies, at an oblique angle, into a series of bulls eye artifacts. A method of finding local anomalies and their strike along lines based upon minimum variance principles reduces these effects. This technique has significant impact on the quality of output grids.