A ground penetrating radar survey has been aplied to an archeological site before its excavation. GPR
survey has been very useful to localize and characterize the remains of the Augustinian monastery of Fraga
(Huesca). The presence of metallic remains at the surface and topographic anomalies hasn´t allowed us to
use mathematical interpolations to produce 3D anomaly maps. The characterization has been made manually
with the definition of several degrees of reliability. These degrees allow us to make excavation guides very
comprenhensive where we can express all the information furnished by the GPR profiles