Wave parameter analysis of dielectric anisotropy in maritime pine timber using GPR

The dielectric behaviour of timber in an electrical field depends on many factors, and one of the most important is the direction of the fiber. This work analyses the wave parameter variations of the dielectric response of timber according to the direction of an electrical field applied by ground penetrating radar (GPR) with a 1.6 GHz antenna. Two types of tests were performed on samples of maritime pine timber (Pinus pinaster Ait.). After the acquisition process the propagation velocities, amplitudes, and spectra variations were compared for the studied fiber directions. Interesting differences were found between these parameters when the field was propagated in a parallel direction or perpendicularly to the fiber.