海洋科学2016，Vol.40Issue(11)：138-147,10.DOI:10.11759/hykx20160204001
基于同步风场的机载SAR海浪参数反演方法
A method for retrieving ocean-wave parameters from airborne synthetic aperture radar imagery based on synchronization information of the wind field
摘要
Abstract
Airborne synthetic aperture radar (SAR), which has flexible characteristics, is an effective means of ob-taining regional ocean-wave parameters. These regional ocean-wave parameters are the most fundamental and im-portant marine environmental parameters in dynamic marine processes. Based on the sounding characteristics of airborne SAR, the first-guess spectrum is constructed by combining ocean-wave spectrum model, direction function with the synchronous wind speed and wind direction which match with the inversion region of ocean wave parame-ters temporally and spatially. The synchronous wind speed and wind direction can be obtained from the SAR data itself using the multi-incidence angle method. Next, a simulated SAR image corresponding with the first-guess spectrum can be produced based on the nonlinear image relations between the ocean-wave direction spectrum and the SAR image spectrum. The simulated observed SAR image spectrums are combined as an iterative operation, and the most suitable wave spectrum can be obtained by solving the nonlinear equation. Finally, the wave parameters are obtained using the cross-spectra method, which is used for eliminating the 180° direction ambiguity of ocean-wave propagation. This study proposes a method of retrieving ocean-wave parameters from airborne SAR imagery based on the synchronization information of the wind field. This method entirely utilizes the advantage of airborne SAR in the marine environment by solving the problem of the first-guess spectrum structure that is de-pendent on external wind field in traditional SAR wave parameter inversion. Airborne ocean-wave parameter inver-sion results from synchronized flight tests and survey ship observations yield root-mean-square errors for signifi-cant wave height and wave direction of 0.23 m and 13.23°, respectively. These errors verify the validity of the pro-posed method and provide support for the using ocean-wave parameters retrieved from airborne SAR imagery.关键词
机载合成孔径雷达(SAR)/初猜谱/交叉谱/同步风场/海浪参数反演Key words
airborne synthetic aperture radar/first-guess spectrum/cross-spectra/ocean-surface wind field/ocean-wave pa-rameter retrieval分类
海洋科学引用本文复制引用
戈书睿,艾未华,袁凌峰,程玉鑫,马烁..基于同步风场的机载SAR海浪参数反演方法[J].海洋科学,2016,40(11):138-147,10.基金项目
江苏省气象探测与信息处理重点实验室基金(KDXS1307) （KDXS1307）
国家自然科学基金(41475019,41306187,41505016) （41475019,41306187,41505016）
