f Fixed source EM two-dimensional modelling using finite elements with quadrature base functions

Although 2-D modelling has been widely applied to the magnetotelluric method, few results have been published for frequency EM controlled source methods, besides the work of J. Doherty (1988) using surface integral equations. Because it allows to deal with more complex modeis, the finite element techniques (J.H. Coggon, 1971, L. Rijo, 1977) is the most popular, but its application to controlled source EM requires specific improvements of the algorithm, as shown in the following.