US Patent 10948588 Synthetic-aperture radar device

A synthetic-aperture radar device of the present invention is the one having: a focal point information storing unit storing a plurality of pieces of focal point information determining positions of focal points; an image reproducing unit reproducing each radar image corresponding to the plurality of pieces of focal point information stored in the focal point information storing unit from a reception signal of a radio wave applied from a moving platform to an observation target and reflected by the observation target; an index calculating unit calculating an index representing an image forming state of the radar image reproduced by the image reproducing unit for each predetermined area; and a synthesizing unit synthesizing the plurality of radar images on the basis of the index calculated from each of the plurality of radar images, enabling obtaining a clear radar image without using positional information of the observation target.