A solar calibration method for microwave Aperture Synthesis Radiometers

The calibration of a microwave Aperture Synthesis Radiometer (ASR) is necessary for high-quality passive microwave imaging. Existing external calibration methods have difficulties for calibration of ASRs with large arrays. In this paper, a data model of correlation matrix containing phase and amplitude errors is established. Based on the correlation matrix, a solar calibration method for ASR is proposed to solve the problem. In the method, the amplitude errors are calculated by using the diagonal elements of the correlation matrix, and the phase errors are computed by employing the eigenvalue decomposition. The performance of the method is validated with the HUST-ASR system. Experimental results show that the microwave brightness temperature images with good quality are achieved.