Exploration and Validation of Wave-Height Measurement Using Multifrequency HF Radar

For operations across a wide range of oceanographic conditions, a radar system able to operate at more than one frequency is theoretically and experimentally recommended for robust wave measurement in recent years. To obtain more sea-state information by HF radar, a multifrequency HF (MHF) radar system, which can simultaneously operate at four frequencies at most in the band of 7.5-25MHz, was developed by the Radio Wave Propagation Laboratory of Wuhan University in 2007. This paper mostly focuses on detailing the data process method of MHF radar wave-height estimation. According to different bands of operating frequencies, a least-mean-square (LMS) linear fitting method is adopted to calibrate wave-height estimation formulation, which is introduced by Barrick to extract significant wave height from backscatter Doppler spectra. Both the wave-height measurements of the initial and modified methods are compared with wave buoy measurements. Afterward, a data fusion algorithm of multifrequency estimates based on relevant factors quantification is discussed step by step. Three comparisons between radar-derived and buoy-measured estimates are presented to illustrate the performance of the MHF radar wave-height measurement. The statistics of the MHF radar wave-height measurements are listed and analyzed. The results show that the wave-height measurements of the MHF radar are in reasonable agreement with the measurements of the wave buoy. © 2013 American Meteorological Society.