The Influence of Different Spatial Resolutions on the Retrieval Accuracy of Sea Surface Wind Speed With C-2PO Models Using Full Polarization C-Band SAR

• Published in: IEEE transactions on geoscience and remote sensing 2017-09, Vol.55 (9), p.5015-5025
• Main Authors: Kangyu Zhang, Xiazhen Xu, Bing Han, Mansaray, Lamin R., Qiaoying Guo, Jingfeng Huang
• Format: Article
• Language: English
• Subjects: Accuracy; C band; Cross polarization; Geophysics; Image transmission; Meteorological satellites; ocean surface wind; Polarization; Radar imaging; Retrieval; SAR (radar); Sea measurements; Sea surface; Spatial discrimination; Spatial resolution; Surface wind; Synthetic aperture radar; synthetic aperture radar (SAR); Temperature (air-sea); Vertical polarization; Wind speed
• ISSN: 0196-2892; 1558-0644
• DOI: 10.1109/TGRS.2017.2700942

This paper presents a comparison strategy for investigating the influence of spatial resolutions on sea surface wind speed retrieval accuracy with cross-polarized synthetic aperture radar images. First, for wind speeds retrieved from vertical transmitting-vertical receiving (VV)-polarized images, the optimal geophysical C-band model (CMOD) function was selected among four CMOD functions. Second, the most suitable C-band cross-polarized ocean (C-2PO) model was selected between two C-2POs for the VH-polarized image data set. Then, the VH-wind speeds retrieved by the selected C-2PO were compared with the VV-polarized sea surface wind speeds retrieved using the optimal CMOD, which served as a reference, at different spatial resolutions. Results show that the VH-polarized wind speed retrieval accuracy increases rapidly with the decrease in spatial resolutions from 100 to 1000 m, with a drop in root-mean-square error of 42%. However, the improvement in wind speed retrieval accuracy levels off with spatial resolutions decreasing from 1000 to 5000 m. This demonstrates that the pixel spacing of 1 km may be the compromising choice for the tradeoff between the spatial resolution and wind speed retrieval accuracy with cross-polarized images obtained from RADASAT-2 fine quad-polarization mode.