Bat-inspired multi-harmonic waveforms

Bats achieve remarkable target detection and selection performance in the most challenging environments. These activities are carried out mainly by echolocation, i.e. by transmitting pulses at ultrasound frequencies and processing the echoes from targets. Because they have relied on high level performance for survival, as a consequence of natural selection, it is believed that they have evolved in order to optimise these capabilities. Echolocation calls are very sophisticated, diverse, and commonly composed of a number of harmonic components. If evolution has resulted in multi-harmonic waveforms there might be advantages deriving by doing so. In this paper we simulate multi-harmonics waveforms and exploit advantages or disadvantages by a range analysis of their ambiguity functions. Results are discussed in relation to the radar and sonar case.