O. V. Sytnik, I. A. Vyazmitinov, Ye. I. Myroshnichenko
The problem of synthesing the efficient technical facilities of detecting live human beings behind opaque barriers is considered. The main attention is focused on synthesing of adequate stochastic informative proceses models. The results of theoretical and experimental researches of the signals reflected from a man are presented. Spectral and temporal realization of informative processes and their statistical descriptions is considered. The experimens indicated that human-returned spectra are time-variable. Therefore the Fourier-analysis is inefficient for signal procesing. In the time domain the observable proceses have pronounced properties with temporarily unsteady periods.
It is shown that in the decimetric waves range the informative process, generated by phase modulation of the reflected signal, caused by man breathing, possesses properties of the periodically correlated stochastic processes. Statistical descriptions of these processes are calculated on a equidistant grating with period equal to that of processes correlation. A stochastic criterion is offered for estimation of correlation period. The magnitude of variance is the basis of the criterion. This variance is calculated of the whole realization as a function of a grating period. This function is polymodal having the peaks at the points of a grating period. The true period of this function corresponds to a global peak. The property of ergodicity of process on a equidistant grate theoretically proved and experimentally confirmed. The requirements for signal proceses hardware are formulated.