Defect detection in wooden logs using ground penetrating radar

Presently there are no suitable non-invasive methods for precisely detecting the subsurface defects in logs in real time. Internal defects such as knots, decays, and embedded metals are of greatest concern for lumber production. Nondestructive scanning of logs using Ground Penetrating Radar (GPR) to detect defects in logs prior to sawing can greatly increase the productivity and yield of high value lumber, and prevent damage to saw blade from embedded metals. In this research, the GPR scanned data has been analyzed to detect subsurface defects such as metals, decays, and knots. Also, GPR offers high speed scanning capability which is needed for future on-line implementation in saw mills. This paper explains the advantages of the GPR technique, experimental setup and parameters used, and data processing for detection of subsurface defects in logs. The results show that GPR can be a very promising technique for future on-line implementation in saw mills.