Obtaining Images in a Multiposition System of Synthetic Aperture Radars in the Case of Insufficient Accuracy of Navigation Data

We consider the influence of the navigation data on the radar-image quality in a multiposition synthetic aperture radar system. We propose algorithms for adaptive synthesis with additional focusing, which provide both refinement of the navigation data using the primary radar information and the synthesis of images with improved quality. The proposed algorithms are efficient for processing the radar information obtained as a result of both the multiposition and monostatic survey. Using an example of processing the radio holograms, which were obtained from an airborne synthetic aperture radar with inaccurate navigation information, we show the efficiency of the method of a posteriori focusing, determine its efficiency conditions, and conclude on the necessity of adaptation (a priori focusing) in the case of insufficient accuracy of the navigation data. We take into account that the laws of motion of a couple of carriers can formally be reduced to the law of motion of an equivalent monostatic carrier.