This paper describes the theory and practice of ground penetrating radar (GPR) clutter characterization and removal. Clutter and target parametric and non-parametric modeling methods are described and results of these methods on laboratory data are presented. Data were collected at the Technische Universitaet Ilmenau using a 6 GHZ frequency- stepped GPR. Targets were chosen to include rocks and other non-lethal clutter which normally present false targets to the GPR. Results indicate a quantifiable improvement in target class discrimination using the clutter reduction methods over standard mean background removal methods.