First-Order Peaks Determination for Direction-Finding High-Frequency Radar

Abstract

Direction-finding (DF) high-frequency radar (HFR) is preferred among the HFR family and is widely used around the world due to its compact structure. The correct determination of first-order peaks (FOPs) from Doppler spectra recorded by radar is a critical step toward attaining accurate mappings of surface currents. The commonly used FOPs determination method is generally sufficient for most situations. However, it needs six user-defined input parameters. These parameters result in complex procedures of optimizing the values of these six user-defined parameters. To simplify the FOPs determination for DF HFR, we propose an alternative method which only needs one user-defined parameter. To validate the reliability of the proposed method, we compare the FOPs determination results derived from the proposed method with those from the commonly used method on a data set covering a period of 256 days. The results indicate that the proposed method yields a similar FOPs determination result to the commonly used method. This proposed input-parameter-reduced method can greatly simplify the use of the HFR for users who are unprofessional in the HFR and promote the popularization and application of HFR.

On the Indirect Estimation of Wind Wave Heights over the Southern Coasts of Caspian Sea: A Comparative Analysis

“…Heron and Heron [48] originally showed the relationship between wave height (m) root mean square (RMS) extractions from high frequency and back spectrum associated with ocean waters, respectively, and compared the three different methods. Each of them depends on the ratio of second-to first-order energies, as proposed by the well-known Barrick method [49][50][51]. The most evident differences between altimetry-and buoy-based wave heights (m) in terms of root mean square error (RMSE) were accepted as a fitting measurement, and a reference RMSE equal to 0.07 m was selected.…”