An Algorithm for Wind Direction Retrieval From X-Band Marine Radar Images

Rain-Contaminated Region Segmentation of X-Band Marine Radar Images With an Ensemble of SegNets

“…For example, for radar images obtained under low or medium wind speeds, rain significantly affects the sea surface roughness generated by wind and blurs wave signatures. On the other hand, it has been observed in previous studies [2], [18] that under high wind speeds, rain may not blur the wave signatures in radar images because wind force dominates the generation of surface roughness. In consequence, rain only causes additional radar backscatter and does not affect the accuracy of wave and wind directions estimation significantly.…”

Ocean Wind and Wave Measurements Using X-Band Marine Radar: A Comprehensive Review

“…However, if the radar data is contaminated by rain, less reliable wind measurements generally result. Recently, Wang and Huang [53] found that when the wind speed is high (over about 8 m/s), obtaining wind direction using the CF-based method in [47] is not significantly affected by rain. However, the accuracy may substantially decrease if the radar images are acquired during rain events under low wind speed.…”

“…However, the accuracy may substantially decrease if the radar images are acquired during rain events under low wind speed. Thus, a method to estimate wind direction based on the 1D spectral analysis (1D-SA) of radar backscatter in the wavenumber domain is proposed in [53]. Later, Huang and Wang [54] extended the 1D SA-based method for wind speed estimation from both rain-free and rain-contaminated radar data.…”

“…After the parameters are determined based on (7), wind speed can be estimated from S T for any radar data. The Decca radar data as described in Section 2.2.1-B were used to test the method [53,54]. Both the single-CF and 1D-SA methods were applied.…”

“…Otherwise, it is categorized as a rain-free radar image. For a rain-contaminated image, if the high-pixel percentage (HPP) [53], which is defined as the ratio of the number of pixels with intensity levels higher than 100 to the total number of pixels, is higher than 30%, the image is classified as a high-wind-speed rain-contaminated image. Otherwise, it is categorized as a low-wind-speed rain-contaminated image.…”