Wave Height Estimation from First-Order Backscatter of a Dual-Frequency High Frequency Radar

Second-order scattering based wave height measurement with high-frequency (HF) radar has always been subjected to problems such as distance limitation and external interference especially under low or moderate sea state. The performance is further exacerbated for a compact system with small antennas. First-order Bragg scattering has been investigated to relate wave height to the stronger Bragg backscatter, but calibrating the echo power along distance and direction is challenging. In this paper, a new method is presented to deal with the calibration and improve the Bragg scattering based wave height estimation from dual-frequency radar data. The relative difference of propagation attenuation and directional spreading between two operating frequencies has been found to be identifiable along range and almost independent of direction, and it is employed to effectively reduce the fitting requirements of in situ wave buoys. A 20-day experiment was performed over the Taiwan Strait of China to validate this method. Comparison of wave height measured by radar and buoys at distance of 15 km and 70 km shows that the root-mean-square errors are 0.34 m and 0.56 m, respectively, with correlation coefficient of 0.82 and 0.84.

[1]  Ali Khenchaf,et al.  HFSW Radar Model: Simulation and Measurement , 2010, IEEE Transactions on Geoscience and Remote Sensing.

[2]  D. Trizna,et al.  Mapping of North Atlantic winds by HF radar sea backscatter interpretation , 1973 .

[3]  Donald E. Barrick,et al.  First-order theory and analysis of MF/HF/VHF scatter from the sea , 1972 .

[4]  E.D.R. Shearman,et al.  Propagation and scattering in MF/HF groundwave radar , 1983 .

[5]  Donald E. Barrick,et al.  The ocean waveheight nondirectional spectrum from inversion of the HF sea-echo Doppler spectrum , 1977 .

[6]  Lucy R. Wyatt,et al.  Limits to the Inversion of HF Radar Backscatter for Ocean Wave Measurement , 2000 .

[7]  Hao Zhou,et al.  Measurement of High and Low Waves Using Dual-Frequency Broad-Beam HF Radar , 2014, IEEE Geoscience and Remote Sensing Letters.

[8]  Lucy R. Wyatt.  Wave measurements from the Australian Coastal Ocean Radar Network , 2014, OCEANS 2014 - TAIPEI.

[9]  T. Schlick,et al.  An Empirical Method to Derive Ocean Waves From Second-Order Bragg Scattering: Prospects and Limitations , 2006, IEEE Journal of Oceanic Engineering.

[10]  Biyang Wen,et al.  Design and Implementation of a Dual-Frequency Compact Antenna System for HF Radar , 2017, IEEE Antennas and Wireless Propagation Letters.

[11]  J. Crease.  The Dynamics of the Upper Ocean , 1967 .

[12]  B. Lipa,et al.  Directional wave information from the SeaSonde , 2005, IEEE Journal of Oceanic Engineering.

[13]  T. Barnett,et al.  Measurements of wind-wave growth and swell decay during the Joint North Sea Wave Project (JONSWAP) , 1973 .

[14]  J. D. Milsom.  HF groundwave radar equations , 1997 .

[15]  Walter Munk,et al.  Wave directional spectra from synthetic aperture observations of radio scatter , 1974 .

[16]  Klaus-Werner Gurgel,et al.  Wind-speed inversion from HF radar first-order backscatter signal , 2011, Ocean Dynamics.

[17]  Ke Li,et al.  A new fully-digital HF radar system for oceanographical remote sensing , 2013, IEICE Electron. Express.

[18]  Clifford R. Merz,et al.  Assessment of CODAR SeaSonde and WERA HF Radars in Mapping Surface Currents on the West Florida Shelf , 2014 .

[19]  Yukiharu Hisaki.  Development of HF radar inversion algorithm for spectrum estimation (HIAS) , 2015 .

[20]  A. Kirincich,et al.  Remote Sensing of the Surface Wind Field over the Coastal Ocean via Direct Calibration of HF Radar Backscatter Power , 2016 .

[21]  Donald E. Barrick,et al.  Theory of HF and VHF Propagation Across the Rough Sea, 1, The Effective Surface Impedance for a Slightly Rough Highly Conducting Medium at Grazing Incidence , 1971 .

[22]  Lucy R. Wyatt,et al.  Factors Affecting the Accuracy of SHOWEX HF Radar Wave Measurements , 2005 .

[23]  W. Pierson,et al.  A proposed spectral form for fully developed wind seas based on the similarity theory of S , 1964 .

[24]  Hao Zhou,et al.  Wave Height Extraction From the First-Order Bragg Peaks in High-Frequency Radars , 2015, IEEE Geoscience and Remote Sensing Letters.

[25]  Donald E. Barrick,et al.  Methods for the extraction of long‐period ocean wave parameters from narrow beam HF radar sea echo , 1980 .

[26]  Matthias Patzold,et al.  Design and analysis of a one-dimensional sea surface simulator using the sum-of-sinusoids principle , 2015, OCEANS 2015 - MTS/IEEE Washington.