一维综合孔径辐射计相位定标研究

Research on Phase Calibration for One-Dimensional Synthetic Aperture Radiometer

相位是一维综合孔径辐射计获得高精度海面亮温的关键因素.传统的一维综合孔径辐射计的相位标定方法难以满足高精度相位定标需求,本文提出一种基于外部点源和内部噪声源相结合的相位定标方法.首先通过不同位置的外部点源和内部噪声源获得不同方位角上接收链路的固定相位差;接着通过内部噪声源获得接收链路的可变相位差;最后综合利用此两种相位差进行相位定标.本方法将固定相位误差和变化相位误差相分离,具有定标精度高、重复性好、节约定标时间的优点.实验表明本方法相位定标精度约为0.7°、重复性约为0.35°.

Phase is important for acquiring the high sea surface brightness temperature with high accuracy.The tradi⁃tional phase calibration methods for one-dimensional synthetic aperture radiometer are difficulty to meet the requirements.This paper proposes a phase calibration method.Firstly,the fixed phase difference of receiving chain at different position is acquired by external point source and internal noise source.Then,the variable phase difference of receiving chain is ac⁃quired by internal noise source.Finally,the phase is calibrated by the two kinds of phase difference.This method separates the fix phase error and variable phase error,and has advantages of high accuracy,good repeatability and saving calibration time.The experiment results indicate that the accuracy is better than 0.7°and the repeatability is better than 0.35°.