Choice of Modulating Frequency of SFM in Active Sonar Applications

Abstract

The development of an active sonar system requires knowledge of the properties of the waveforms transmitted by that system. The choice of waveform will determine the ability of the system to resolve targets in range and Doppler, and will also impact the detection capabilities of the system. Modulating the frequency or the amplitude of the transmitted waveform will result in an increased time-bandwidth product. Amplitude modulation, however, results in degradation of power efficiency, so it is more common to use frequency modulated signals. Active sonar performance also depends on reverberation rejection, and thus on pulse design.. This paper is based on matlab simulations, and primarily focuses on the effect of choice of modulating frequency of sinusoidal frequency modulated signals (SFM) on their performance in active sonar systems. The ability of SFM to reject reverberation and avoid mutual interference will also be discussed.