A new nonlinear approach to extraction of ocean wave spectra from bistatic Doppler HF-radar data

Knowledge of the ocean wave spectrum, from which many important ocean parameters can be extracted, is crucial to understand the ocean's behaviour. Due to the intricate nature of ocean wave spectrum extraction from HF radar data, previously-devised methods relied on making a linear approximation to the original nonlinear problem or resorted to constraining the solution space, in order to simplify the solution process. This problem is aggravated in a bistatic configuration due to its geometrical complexity. The present work proposes a change of variables in the second-order radar cross-section from bistatic HF-Radar in order to extract the ocean power spectral density from Doppler HF-Radar data. The main advantage of the proposed method is the possibility of extracting the ocean wave spectrum without assuming any linear approximation to the inverse problem. In this work, it is found that the proposed method can accurately extract the ocean wave spectrum from bistatic HF radar data under a variety of ocean conditions.