Abstract
The Gaussian enveloped linear chirp (GELC) reflectometry is introduced to localize the impedance discontinuities on the instrument cable used in nuclear plants. The GELC reflectometry uses a phenomenon that electromagnetic pulses are reflected at the impedance discontinuities to localize impedance discontinuity points on the cable. For localizing impedance discontinuities, time delays between the incident signal and the reflected signals from the impedance discontinuities have to be measured. The GELC is modeled by second order auto-regressive (AR) model. From the coefficients of the AR model, instantaneous frequency is estimated by the recursive robust least squares filtering to calculate the time delays. The performance of the proposed method is verified by experiments.
