Contribution of GPR method in monitoring and evaluating the conservation state of Fortezza, Rethymno, Greece

Under the framework suggested by STORM project for the conservation and protection of Cultural Heritage monuments, a GPR system equipped with 250MHz and 500MHz antennas was used at the pilot site of Fortezza, in the old town of Rethymno, to examine the capability of the method to detect both cracks and changes in wall thickness. The data presented here were collected in four different phases. The results suggest that both frequencies are capable to monitor changes in wall thickness, with the 250MHz antenna performing better than the 500MHz antenna. For the case of cracks, the 500MHz antenna produced more detailed results but due to high noise levels further processing is required. Overall, GPR seems to be a promising method in monitoring the conservation state of the walls. 1 6