Airborne Electromagnetic Systems

Abstract

AEM systems are essential tools for a wide range of mineral exploration and geological or environmental mapping applications. The product of peak dipole moment and the Liu waveform factor provides a quantitative estimate of the effective signal strength of a TEM system at a specific base frequency, and can be used to ``compare' systems. Given also the noise levels of an AEM system and its frequency or time sampling, it is easy to predict the capabilities and resolution of the system. The most challenging development required of AEM is the development of systems operating at 5 Hz or less to penetrate conductive cover and assist in the discrimination of very conductive copper/nickel sulphide deposits. Altimeter errors provide the main limitations in depth resolution of shallow environmental targets. 2D and 3D imaging and inversion strategies are not yet reliable or fast enough for routine application.