Research On Correction Of Phase Errors Caused By Ionosphere

This paper presents a new method to correct the phase error caused by ionospheric disturbance in the synthetic aperture radio imaging. Entropy is used to measure the quality of the image. Smaller entropy means better quality. The phase error is corrected such that the entropy of the image is minimized. Compared with the traditional methods, which always call for additional data such as the data from standard sources or the measurement at another frequency, the proposed scheme only uses the dirty map itself to correct the phase error. In this paper, the principle, the algorithm, and the results of the minimum-entropy method are discussed in detail.