Automated RF tomographic imaging of utility poles above and below ground

This paper describes the development of a 3-D scanning system and associated signal processing for carrying out non-destructive imaging of wooden utility poles. While nominally rod-shaped, natural variations in the original tree, its cut, and any attached street furniture impose considerable complexity to automating the task of scanning a pole. While RF tomographic techniques are theoretically capable of producing images of sufficient quality to assess pole degradation, spectrum constraints; the need for a low-cost, efficient and reliable scanning device and the additional complexity of making subsurface measurements through heterogeneous material combine to make this a challenging task. Ground-truth data obtained from a medical CAT scanner and a customised experimental apparatus are described, along with progress made in the selection of appropriate scanning and processing mechanisms.