Geintra

This work proposes a semi-empiric model for a turbulent atmosphere as a dynamic channel of transmission of narrow-band ultrasonic signals. It is based on a theoretical expression for the coherence time derived in a previous paper, and on the results obtained from the experimental analysis of propagation of a 50 kHz ultrasonic tone under different turbulence conditions. The model is used to predict the effects of a turbulent atmosphere on the propagation of binary encoded signals and their consequent detection by matched filtering. These predictions are compared with the results obtained with a real pulse compression system operating outdoors.