综合孔径辐射计误差会严重影响系统的性能。文中提出了一种新的接收机误差校正方法。该方法包括一个校正矩阵和一种自动校正通道频率响应变化的方法。校正矩阵通过测量系统天线范围内的冲击响应得到。除了基线消条纹误差,该校正矩阵可以在图像重建过程中校正其他的接收机误差。自动校正方法则可以校正通道幅度和相位的时变误差。该方法能简化校正的步骤,减小了校正系统引入的额外误差。仿真结果表明,该校正方法能很好地改善综合孔径辐射计的成像质量。
The system imperfections have great influence on the performance of aperture synthesis radiometers (ASRs). A new error receiver calibration method is presented for ASRs in this paper, which consists of a calibration matrix and an automatic calibration method for channel frequency response variation. The calibration matrix consists of the impulseresponses of ASRs measured in the antenna range. Most receiver errors except baseline fringe-washing error can be eliminated with the improved calibration matrix in the image reconstruction. The automatic calibration method can calibrate the channel amplitude and phase errors changing with time. This new calibration method can simplify the calibration procedures and decrease the additional errors introduced by calibration system. Simulations show the new calibration method can greatly improve the image quality of ASRs.