旋转扫描扇形波束散射计(Rotating Fan-beam SCATterometer, RFSCAT)是一种新体制的海洋风场测量雷达散射计。RFSCAT对同一观测面元能够提供更多的方位角和入射角观测组合，改善海面风矢量场的反演精度。为了达到设计的风场反演精度，系统要求定标精度为0.5 dB。该文基于中法海洋卫星(Chinese French Oceanography SATellite, CFOSAT)雷达散射计的系统参数，考虑了在轨测量的主要误差源，分析了地面扩展目标在轨外定标的特点，给出了可行的RFSCAT在轨外定标方法，并利用仿真数据对该方法进行验证。 利用QuikSCAT散射计的L2A数据和图像重构(SIR)数据，针对地球表面归一化雷达后向散射系数(0)稳定的区域，给出了定标地图，为RFSCAT在轨定标提供参考。
Rotating Fan-beam SCATterometer (RFSCAT) is a new radar scatterometer system for ocean surface vector wind measurement. Compared with other available scatterometers, RFSCAT can provide more combination of azimuth and incidence angles for a single surface resolution cell. To achieve the required wind vector accuracy, radar scatterometry measurement of backscattering coefficient(0) must be calibrated within a few tenths of a decibel. In this paper, the method for external calibration of RFSCAT is proposed, based on the system parameters of the scatterometer onboard the Chinese French Oceanography SATellite (CFOSAT), and is verified by simulations. Then QuikSCAT L2A data and SIR of several large homogenous areas are analyzed to check the stability and azimuthal dependence of the(0) over these areas. A new calibration mask is generated and will be used as a reference for the calibration of RFSCAT.