综合孔径微波辐射计信道误差分析与标定

Analysis and Calibration of the Channels Error of Synthetic Aperture Radiometer

本文首先建立了综合孔径微波辐射计的信道模型 ,在此基础上分析了信道的幅度相位不平衡以及信道间串扰对反演亮温的影响 ,并给出了系统仿真结果 .本文还提出了一种新的系统定标方案 ,与传统定标方法相比 ,该方法可以非常方便的获取高精度的系统调制G矩阵用于亮温反演 .

Theoretical channels model of synthetic aperture radiometer are presented. Based on this model, how amplitude imbalance, phase imbalance and mutual coupling between the different receiving channels effect brightness temperature retrieving is analyzed. The computer simulation results are also presented, in which the cause of the along-track streaks usually appeared in the retrieved image is identified. In addition, a new system calibration approach is introduced to solve this problem: using digital I-Q vector modulators to simulate the point source in the antenna range, we can get more accurate G Matrix to retrieve the brightness temperature image. This new approach, as compared with the existing calibration methods, is especially suitable for in situ use.