Robust processing of magnetotelluric data in the AMT dead band using the continuous wavelet transform

Abstract:

The energy sources for magnetotellurics (MT) at frequencies above are electromagnetic waves generated by distant lightning storms propagating globally within the earth-ionosphere waveguide. The nature of the sources and properties of this waveguide display diurnal and seasonal variations that can cause significant signal amplitude attenuation, especially at frequencies — the so-called audiomagnetotelluric (AMT) dead band. This lack of energy results in unreliable MT response estimates; and, given that in crystalline environments ore bodies located at some depth are sensed initially by AMT data within the dead band, this leads to poor inherent geometric resolution of target structures. We propose a new time-series processing technique that uses localization properties of the wavelet transform to select the most energetic events. Subsequently, two coherence thresholds and a series of …

Año de publicación:

2008

Keywords:

Fuente:

google