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f EXAMPLES OF THE CONTRIBUTION OF A-PRIORI INFORMATION TO IMPROVING INVERSION OF AEM DATA
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 25th Symposium on the Application of Geophpysics to Engineering & Environmental Problems, Mar 2012, cp-329-00141
Abstract
We present a simple yet rigorous way of adding a-priori information to inversion of Airborne EM data, using the Spatially Constrained Inversion. Resistivity models are constrained spatially to reflect the lateral homeogeneity expected from the geology. These constraints, that can be considered “soft a-priori”, are fitted together with the AEM data, during the inversion. Moreover “hard a-priori” can be added: they can be, e.g., downhole resistivity logs, geological contacts and layers, hydrogeological units. The a-priori information is treated as an extra data set, by taking into account location, values, uncertainty, and expected lateral variability. The information it contains is spread to the location of the neighbouring AEM soundings. These fields enter the SCI formulations, with the Obs matrix containing the data (AEM and a priori), the Roughening matrix the constraints, the error matrix the uncertainties for all datasets. Constraints and uncertainties are usually different depending on data types and geology. Different datasets, collected by various AEM systems, have been used.