Particle Swarm Optimization (PSO): a Simple And Powerful Algorithm Family For Geophysical Inversion

PSO is an optimization technique that has been successfully used in many different engineering fields. The PSO algorithm can be physically interpreted as a stochastic damped mass-spring system. This analogy served us to introduce the PSO continuous model and to deduce a whole family of PSO algorithms arising from the discretization of the PSO continuous model. We also analyze their respective first order and second order stability regions from the stochastic point of view. Their performance is also checked using synthetic functions showing a degree of illposedness similar to that found in many geophysical inverse problems. Finally we present the application of these algorithms to the analysis and solution of a VES inverse problem associated to a seawater intrusion in a coastal aquifer in South Spain.