Removal of herringbone effects from AEM data maps using the Radon transform

Abstract

Airborne electromagnetic (AEM) data maps acquired using fixed-wing towed-bird configurations often exhibit so-called 'herringbone effects', distortions of features at the edge of a conductor as a result of an asymmetric measuring system flying along adjacent profile lines in opposite directions. The presence of herringbones in AEM data distorts an AEM map and makes interpretation difficult. This paper describes a process to remove herringbones from AEM data by the application of the Radon transformation, and filtering in the Radon domain. Inverse Radon transformation produces an AEM data map with reduced herringbone effects. The method is tested on the synthetic response of 3-D conductors located in a uniformly conductive half-space, as measured by a towed bird AEM system such as GEOTEM or QUESTEM, and is successfully applied to field data acquired using the GEOTEM system.