ISSN:
1573-4862
Keywords:
Nondestructive testing
;
eddy current inspection
;
Lissajous patterns
;
fast Fourier transform
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Mathematics
Notes:
Abstract In this paper, we present two methods for estimating the mixing parameters used in scaling, rotating, and time shifting discrete time eddy current impedance plane trajectories in order to suppress unwanted support plate signals. One method operates directly on the time signals. The other method operates on the frequency domain representation of these signals and consequently is computationally more involved. Both methods require the minimization of a functional which measures the energy difference between the horizontal and vertical components of the high and low frequency data. Three illustrative examples are presented, and it is shown that the use of the frequency domain method is justified if the data are corrupted with random noise as well as with unknown multisample time shifts.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00568761
