Bragg Peak Detection Using Compatible Mother Wavelet on Oceanographic HF Radar Signals

High-frequency surface wave radar (HFSWR) has been proven as a long-range sensor for estimating the sea state. The coupling between radar wave and dynamic sea surface produces the Bragg components in the Doppler space of received signals. These components contain the sea-state information, which can be extracted by using an inversion algorithm. However, the dense traffic and any natural phenomena on the HF spectrum cause the received signal to be mixed up with clutters and interference, sometimes overlap in time, frequency, and Doppler domain. This research considered the discrete wavelet transformation (DWT) to decompose the radar signal and highlight the Bragg peaks. The choice of mother wavelet highly influences the wavelet. Thus, the scrutiny was initialized by selecting the mother wavelet as reported in this paper. The results show the 6-order Daubechies (db6) and 3-5 pairs of biorthogonal (bior3.5) functions at level 3 of DWT can detect the proper position of Bragg peaks.