BASICS OF IDENTIFYING METHODOLOGY OF THE IMPACT TYPE ON PERIMETRAL FIBER-OPTIC SECURITY SYSTEM

Abstract

The article describes the principles of fiber-optic system operation of vibroacoustic monitoring. The methodology of identification of impact on the perimetral fiber optical system is developed on the example of signals obtained when testing the system on the testing ground. The article describes fiber-optic system, the location of the cable sensor for test experiments. It shows the signals from the two types of impact on the secured perimeter: short-term (d-effect); extended in time (t-effect). The article presents the total Fourier-transform of these effects in three independent implementations that show the characteristic differences of these two effects in the frequency domain. The d-effect demonstrates itself across the frequency domain involved by the system, and the t-effect only in the low-frequency region. These differences in the frequency domain are the basis of the criterion for identifying these two types of effects. More clearly the difference between these types is shown in cross-spectra where coinciding harmonics intensify each other. The revealed features of fiber-optic system signals in the Fourier spectra and cross-spectra have allowed us to develop a method of identifying d or t-effects on perimetral security system.