Development of polarization ratio model for sea surface wind field retrieval from TerraSAR-X HH polarization data

Shao W, Li XM, Lehner S, Guan C (2014)

Publication Type: Journal article

Publication year: 2014

Journal

International Journal of Remote Sensing Taylor & Francis: STM, Behavioural Science and Public Health Titles / Taylor & Francis

Book Volume: 35

Pages Range: 4046-4063

Journal Issue: 11-12

DOI: 10.1080/01431161.2014.916059

Abstract

In this article, the polarization ratio (PR) of TerraSAR-X (TS-X) vertical-vertical (VV) and horizontal-horizontal (HH) polarization data acquired over the ocean is investigated. Similar to the PR of C-band synthetic aperture radar (SAR), the PR of X-band SAR data also shows significant dependence on incidence angle. The normalized radar cross-section (NRCS) in VV polarization data is generally larger than that in HH polarization for incidence angles above 23°. Based on the analysis, two PR models proposed for C-band SAR were retuned using TS-X dual-polarization data. A new PR model, called X-PR hereafter, is proposed as well to convert the NRCS of TS-X in HH polarization to that in VV polarization. By using the developed geophysical model functions of XMOD1 and XMOD2 and the tuned PR models, the sea surface field is retrieved from the TS-X data in HH polarization. The comparisons with in situ buoy measurements show that the combination of XMOD2 and X-PR models yields a good retrieval with a root mean square error (RMSE) of 2.03 m s-1 and scatter index (SI) of 22.4%. A further comparison with a high-resolution analysis wind model in the North Sea is also presented, which shows better agreement with RMSE of 1.76 m s-1 and SI of 20.3%. We also find that the difference between the fitting of the X-PR model and the PR derived from TS-X dual-polarization data is close to a constant. By adding the constant to the X-PR model, the accuracy of HH polarization sea surface wind speed is further improved with the bias reduced by 0.3 m s-1. A case acquired at the offshore wind farm in the East China Sea further demonstrates that the improvement tends to be more effective for incidence angles above 40°. © 2014 © 2014 Taylor & Francis.

Involved external institutions

Zhejiang Ocean University / 浙江海洋学院 CN China (CN) Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR) / German Aerospace Center DE Germany (DE) Ocean University of China / 中国海洋大学 CN China (CN)

How to cite

APA:

Shao, W., Li, X.M., Lehner, S., & Guan, C. (2014). Development of polarization ratio model for sea surface wind field retrieval from TerraSAR-X HH polarization data. International Journal of Remote Sensing, 35(11-12), 4046-4063. https://doi.org/10.1080/01431161.2014.916059

MLA:

Shao, Weizeng, et al. "Development of polarization ratio model for sea surface wind field retrieval from TerraSAR-X HH polarization data." International Journal of Remote Sensing 35.11-12 (2014): 4046-4063.

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