Title :
Transients in circular symmetry; estimation of transverse wave propagation velocity
Author :
Axmon, Joakim ; Hansson, Maria
Author_Institution :
Dept. of Appl. Electron., Lund Univ., Sweden
Abstract :
The response of a tree trunk to a hammer blow, measured by sensors positioned around the excited cross section, consists of two kinds of transient mechanical waves: longitudinal P- and transverse S-waves. The aim of this paper is to extract the velocity of the S-waves, using a filtering structure that emphasizes the waves heading in one of the directions along the circumference. By this approach, a more robust estimate of the delay between the channels, compared to, e.g., using the pure discrete Radon transform, is obtained. The method is applied to recordings of a large number of trees, and estimated velocities are reported
Keywords :
array signal processing; delay estimation; elastic waves; filtering theory; forestry; transients; circular symmetry; decay detection; delay estimation; filtering structure; forestry industry; hammer blow; longitudinal P-waves; nondestructive testing; pure discrete Radon transform; transient mechanical waves; transients; transverse S-waves; transverse wave propagation velocity estimation; tree trunk; Clocks; Delay estimation; Force sensors; Forestry; Mechanical sensors; Mechanical variables measurement; Position measurement; Pulse measurements; Robustness; Sparse matrices;
Conference_Titel :
Sensor Array and Multichannel Signal Processing Workshop. 2000. Proceedings of the 2000 IEEE
Conference_Location :
Cambridge, MA
Print_ISBN :
0-7803-6339-6
DOI :
10.1109/SAM.2000.878000
