This paper presents a novel nondestructive approach for determining th
e presence of rot in wood telephone/utility poles carrying telephone a
nd power lines. The method requires determination of the reflection co
efficient of the buried end of the pole using physical point measureme
nts such as position, acceleration, or strain. Wave propagation analys
is is used to characterize the one-dimensional structural dynamics of
the wood pole. This approach permits directional wave components which
propagate up and down the pole to be extracted using a previously dev
eloped wave filtering scheme.((1,2)) These sensed directional wave com
ponents can then be used to compute the local reflection coefficient o
f a structural discontinuity based on longitudinal, transverse, or tor
sional excitation. The reflection coefficient yields information about
the location and extent of pole rot in wood utility poles. Temporal d
ata of incident and reflected wave components also permits a visual ch
aracterization of the effect of pole rot on the structural response of
the utility pole. Experimental results are obtained on two laboratory
test specimen excited in the axial direction to confirm analytical pr
edictions.