Extraction of swell parameters from simulated noisy HF radar signals

Based on the previously developed monostatic HF radar cross section model for swell contaminated seas, a new inversion algorithm for swell information from radar sea echoes is proposed. The received electric field time series with external white Gaussian noise is first simulated, from which the Doppler spectrum is obtained as a periodogram. Next, all swell peaks in the spectrum are identified and processed with a robust peak recognition routine, and the positions of those peaks are used to calculate the period and dominant direction of swell. Finally, the half-power width of each swell peak is extracted in order to derive the frequency spreading of the unknown swell wave height spectrum. Simulation results show that the method proposed in this paper provides precise estimates of the swell parameters under different sea states, and improves the generality of traditional inversion algorithms.