An efficient 1D OCCAM'S inversion algorithm using analytically computed first- and second-order derivatives for DC resistivity soundings

摘要

An efficient algorithm has been developed for ID resistivity inversion problem using both first- and second-order derivatives, which are computed analytically. The second-order derivative matrix, which is not used in the OCCAM's inversion, has been incorporated into the algorithm employing analytical expressions. Computation of complicated second-order derivatives in each iteration is circumvented by a new algorithm. These modifications result in stable convergence of the OCCAM's inversion and in general, better misfit can be achieved specially for smoothing parameter, mu < 1. The modified inversion algorithm, coded in MATLAB was tested using two synthetic Schlumberger resistivity sounding examples. Its application has been illustrated with field data from south India. (c) 2004 Elsevier Ltd. All rights reserved.