Resolution Performance of Modulated Acoustic Signal Inspired by Bat

摘要

For smart ultrasonic detecting system of underwater weapons, there is Doppler effect cause by moving target for echo's complex envelope. The broad band ambiguity functions of symmetry triangle linear frequency modulation impulse signal, distance and velocity are derived by the definition of broad band ambiguity function. The symmetry characteristic of symmetry triangle linear frequency modulation impulse signal broad band ambiguity function is described. With broad band ambiguity function, the phenomena of the coupling echo from moving target for distance and velocity as well as wave distortion are explained. By analyzing the distance broad band ambiguity function, the conclusion is gained as that the distance theoretical resolution is inversely proportional to band width. Furthermore, the velocity resolution is correlative to velocity, time width, band width and carrier wave frequency, so that the theoretical foundation of parameters selection by the demand of engineering is put forward.