Case history of radar system and imaging techniques to the foundation of the stone pagoda at Chungung-dong, Republic of Korea

n order to test the radar system and the imaging techniques, we applied them to the foundation of the stone pagoda at Chungung-dong, Hanam city. The radar system was the modified Zond-12c georadar system for the survey of stone pagodas. As the imaging techniques, we used 3-D Kirchhoff prestack depth migration and non-linear ray tomography. From the migrated images, we could suppose the boundaries of the foundation stones connected to the outer boundaries. And there were several events in inner structure. Recondtructed cross sectiain showed that the result matched well with the migrated image. Among the outer foundation stones, south and west planes were more damaged than east and north planes. Most of velocity distributions were the same as the propagation velocity of granite, but several parts had higher velocities. It meaned that there were some voids in the foundation of the stone pagoda.