Retrosynthetic aperture radar azimuth calibration method

The invention provides a retrosynthetic aperture radar azimuth calibration method which comprises the steps of carrying out range compression and translation compensation on imaging data, carrying out Keystone transformation correction linear range walking on a self-focused signal, determining medians of effective rotational speeds, a search interval and search point number, carrying out secondary phase term compensation on a signal after keystone transformation with each effective rotational speed to be estimated, carrying out azimuth imaging and obtaining an image entropy, after traversing all the effective rotational speeds to be estimated, searching the minimum image entropy, and taking the effective rotational speed corresponding to the minimum image entropy as the estimated effective rotational speed. After obtaining the estimated effective rotational speed, the search is carried out in a smaller interval near the value, the whole process is iterated for 3-4 times, and very high estimated accuracy can be achieved.