In this paper, a reconstruction methodology for the field emitted by an electronic equipment in a CISPR 25 standard environment is developed. It is based on an inverse method to determine equivalent dipoles representative of the electromagnetic sources. Positions and dipolar moments of equivalent dipoles are obtained via a hybrid optimization method, using a Genetic Algorithm (GA) followed by a Pattern Search (PS) method. First, the validity of the approach is verified with a numerical 3D model of a microstrip line. Then, an experimental protocol, corresponding to the setup of the CISPR 25 standard, is proposed and validated with a monopole antenna as a radiating source. As expected, the measurements obtained with the rod antenna yield some numerical errors related to the equivalent dipoles. However, such a compact model predicts the radiated field with sufficient accuracy to be useful for analyzing several EMC constraints in an automotive context.