Application to Underwater Acoustic Measurements of the FM Signal Modulated by the Smoothed “Random Telegraph Signal”

The probability density of the smoothed random telegraph signal and the power spectra of FM signal modulated by this random signal are experimentally obtained. These FM signals are the noises with power spectrum distributions in Gaussian, rectangular or U-form, these forms being determined by the values of the product of the mean number of zero-crossings per second of the random telegraph signal and the time constant of a low-pass RC-filter driven by the random telegraph signal. Furthermore, these power spectra can be changed by changing FMparameters. These FM signals are suitable for underwater acoustic measurements, and results on the gain characteristics of transducers and the reflection characteristics of a square plate are given as examples.