Performance Evaluation of Sonar Signals using Fusion Technique

In active sonar systems, proper selection of the transmitted waveform is critical for target detection and parameter estimation. Each signal has its own diverse characteristics. Linear FM suffers from relatively high autocorrelation (ACF) side-lobes. The ACF sidelobes could be reduced by shaping the signal; other methods include Gaussian NLFM, Rayleigh NLFM and the combination of both these pulses. No single signal gives better result. To improve system performance there is a need to consider multiple signals and combine them to obtain better detection, especially with the existence of clutter (reverberation). In this paper we are going to combine multiple signals. Three commonly used signals in this are (i) Gaussian NLFM signal (ii) Rayleigh NLFM signal (iii) LFM. Comparison will be made with respect to their ambiguity plots, range resolution plots and parameters like PSLR, ISLR, Merit Factor and Discrimination for single signal and combined signals.