基于星载SAR多普勒速度反演海表流场算法的研究

Study of ocean surface current inversion algorithm based on space-borne synthetic aperture radar dopplervelocity

基于星载合成孔径雷达(SAR)多普勒频移方法(DCA)估计海洋表层流场的技术已日趋成熟,但其反演算法的流程较为复杂,需要对多普勒频移的值进行多次修正。在DCA的基础上,Chapron等提出了多普勒速度与海表流场、海面风场之间的关系模型。本文结合DCA技术、Chapron的模型和M4S微波成像仿真模型,建立了雷达视向海表流速与多普勒速度之间的关系,引入线性回归的思想对公式中的参数进行了计算,并依此给出了海流的反演结果。与DCA方法相比,本文算法减少了计算量,且反演流程得到了优化,仿真反演结果的流速误差不大于0.06m/s,流向误差不大于1°。

The Doppler centroid analysis（DCA）method on estimating ocean surface current field which based on the space-borne synthetic aperture radar（SAR）is becoming mature gradually,but the method is complex in inversion process,and the value of Doppler shifts required corrections repeatedly.On the basis of DCA,Chapron et al.proposed the model among Doppler velocity,ocean current field and sea surface wind field.This paper combines M4 Smodel,which is microwave imaging simulation of SAR,DCA method and Chaprons model,establishes the formula between the Doppler velocity and ocean surface flow velocity,and explains the calculate parameters of the formula with the linear programming.The inversion results are also given out at the same time.Compared with the DCA method,the proposed algorithm of this paper simplified the inversion procedure and reduced the calculation complexity,the error of the experimental results is no more than 0.06m/s,the flow error is no more than 1°.