Radar image recognition by conjugacy criteria with selection of informative angles

We are exploring technology for recognizing radar images of objects observed from different viewing angles. To do this, we use many reference images corresponding to different viewing angles. As a measure of proximity, we use a conjugacy criterion, defined as the squared cosine of the angle between the current image vector and a space formed by the vectors of reference images. Based on the properties of the orthogonal decomposition of the conjugacy criterion, we also construct a computationally simpler approximate proximity criterion. Using the conjugacy criteria, we build a recognition technology with the formation of subsets of reference images corresponding to the most informative angles of the object in the sense of conjugacy criteria to the angle of the current (recognized) object. Results of comparative experiments using the open database of MSTAR radar images are presented, illustrating the quality of recognition with various modifications of the criterion and various sizes of the reference images subsets. Sizes of the reference image subsets are established for which the quality of recognition using the original conjugacy criterion exceeds the recognition quality provided by the familiar methods, with a simpler modified criterion also providing good results.