Design considerations of parametric arrays

This paper is concerned with the design, testing and performance evaluation of parametric array proposed to be used for sub-bottom applications. Some of the main parameters to be considered while designing parametric arrays are primary frequencies, secondary frequencies, transducer array size, transmitted power and the overall system complexity. Choice of these parameters is contradictory and has to be chosen as a compromise between their effects. Such considerations have been discussed in detail and a parametric sonar operating at primary frequencies centred around 40 kHz and capable of generating secondary frequencies ranging from 1 kHz to 10 kHz has been designed. Field trials were carried out in fresh water lake to evaluate its performance by measuring source levels and beam-patterns both at primary and secondary frequencies. The experimental results were found to be in good agreement with the theoretically expected performance.