Design a novel waveform to improve the detection of sonar targets

Detection of underwater targets in high-reverberation and shallow water environments by sonar is a complicated and complex process. In this paper, a hybrid waveform has proposed to improve detection with high range resolution. First, after analyzing the HFM waveform, it was shown that the HFM waveform is a better option than LFM for moving purposes. In the HFM wideband waveform, as the bandwidth increased, the peak-to-side lobe (PSL) ratio increased and the probability of detecting weak targets decreased. Therefore, a method for designing the waveform by separately amplitudes has proposed. Then in order to reduce the peak-to-side lobe ratio (PSLR) ratio and increase the target detection probability (Pd), codes with a minimum peak-to-side lobe ratio to Designed waveform combined. Then, the ambiguity function of the proposed waveform has calculated and plotted, and the Doppler sensitivity property was observed due to the thumbtack-like Ambiguity Function. A distinctive feature of the proposed algorithm is that the transmitted waveform can be designed in proportion to the intended speed of the target, and the probability of detection is significantly improved. The evaluation results show that there was a significant improvement in the PSLR criterion compared to the LFM waveform. Also, in the Q function criterion, the detectable reverberation level of the proposed waveform is significantly superior to other state-of-the-art sonar waveforms.