Theoretical description of the measuring method of instantaneous impedancespectra

Theoretical principles for determination of instantaneous impedance spectra were formulated. Coupling of the pseudo-white noise and short-time Fourier transformation methods allows determination of impedance spectra changes a s the function of time. The theoretical principles of the new measurement m ethod indicate the possibility of conducting impedance investigations of no n-stationary processes. The frequency resolution and time selection of the total time-frequency analysis of impedance spectra depend on the choice of the size of the Gaussian window. (C) 2000 Elsevier Science S.A. All rights reserved.