Increased accuracy for quantitative modelling of Airborne EM data through detailed description of system transfer function and spatially constrained inversion

Abstract

This paper aims at providing more insight into the parameters that need to be modelled during inversion of Helicopter TEM data for accurate modelling, both for hydrogeophysical and exploration applications. We use synthetic data to show in details the effect, both in data and in model space, of the altitude of the Tx and Rx, and then a figure reassuming the effects of all other parameters such as waveform shape, low pass filters, and gate integration. Results from extensive synthetic modelling that will be presented at the conference show how all these parameters need to be taken into account and modelled correctly during inversion of HTEM data. We then present an application of this approach on real VTEM data from an exploration survey. The results from constrained inversion of the VTEM, compared with borehole information and with other modelling methodologies, show its validity.