A transmission radar (1) divides each of multiple frequency bands in such a manner that differences between center frequencies in respective frequency bands after the division are equal, and transmits, in time division manner, transmission signals of which transmission frequencies are the center frequencies in respective frequency bands after the division; a rearrangement processing unit (13) rearranges each of the reception video signals converted by the reception radar (5) in such a manner that sets of reception video signals corresponding to the multiple frequency bands before being divided by the transmission radar (1) are arranged in a row; and a band synthesis processing unit (14) performs a band synthesis on each of the reception video signals rearranged by the rearrangement processing unit (13).