DOI: 10.1002/2016JD025178
论文题名: A damped Newton variational inversion method for SAR wind retrieval
作者: Jiang Z. ; Li Y. ; Yu F. ; Chen G. ; Yu W.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2017
卷: 122, 期: 2 起始页码: 823
结束页码: 845
语种: 英语
英文关键词: synthetic aperture radar
; variational inversion
; wind
Scopus关键词: climate variation
; data inversion
; Envisat
; error analysis
; experimental study
; numerical method
; performance assessment
; synthetic aperture radar
; wind direction
; wind velocity
英文摘要: The variational inversion for synthetic aperture radar (SAR) wind retrieval can take all sources' errors into account, but its iterative computation is very time consuming. For the wind vectors, (u, v) components are commonly used for variational inversion, but they are not intuitive for practical applications. In this paper, we modify the decomposition of wind vectors in the cost function into wind speed and wind direction and adopt the damped Newton method (DNVAR) to solve the cost function. Experimental results on simulated data show that DNVAR can effectively reduce background wind vector errors. Additionally, the average number of iterations is reduced drastically compared to prior arts. Furthermore, a detailed comparison between direct SAR wind retrieval (DIRECT) and DNVAR is performed. Simulations reveal that the DNVAR errors are smaller than the background wind vector errors in all considered cases. Thus, DNVAR could be employed to retrieve SAR sea surface wind. For practical applications, when the background wind speed is within moderate and high wind speed range, DNVAR has higher accuracy and is thus preferred. Otherwise, both DNVAR and DIRECT are feasible, considering the unknown actual errors of both background wind vectors and geophysical model function. Experimental results on Envisat/advanced synthetic aperture radar data show that the wind speed accuracy of DIRECT is largely affected by the background wind direction errors, but DNVAR can reduce the wind direction errors with minor effect on the wind speed errors in comparison with the background wind errors. ©2016. American Geophysical Union. All Rights Reserved.
资助项目: U1406404
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62754
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, China; Institute of Atmospheric Physics, Chinese Academy of Sciences, LAGEO, Beijing, China; Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; College of Information Science and Engineering, Ocean University of China, Qingdao, China
Recommended Citation:
Jiang Z.,Li Y.,Yu F.,et al. A damped Newton variational inversion method for SAR wind retrieval[J]. Journal of Geophysical Research: Atmospheres,2017-01-01,122(2)