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The New Inversion Scheme for Magnetic Resonance Sounding – q-t-Inversion of Complete Data in a Single Step
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Near Surface 2008 - 14th EAGE European Meeting of Environmental and Engineering Geophysics, Sep 2008, cp-64-00009
- ISBN: 978-90-73781-56-6
Abstract
Basically the data for Magnetic Resonance Sounding are in two dimensions: For every pulse moment i.e. excitation intensity q, there is a time t dependent relaxation signal i.e. record. These are to be inverted into depth distribution of water content and rock decay time respectively. Inversion schemes available so far handle the dataset in two steps, either deriving the parameter of each record i.e. amplitude and decay time by fitting, and then inverting these parameter into the subsurface properties or inverting the unfitted records at any time step to subsurface water content and then fitting for the decay times. We present a new scheme that handles the inverse problem in one step using complete data. We assess and examine this new scheme, called q-t-inversion due to the parameter variables, using a synthetic example with realistic field conditions of noise and dead time. The new scheme leads to a higher resolution and is consideably more stable as expected because it is more appropriate for space parameter, which are in physical terms not independent and therefore the resulting observations too.