PURPOSE: To make effective use of the phase information which a synthetic aperture radar image possesses and to lessen the deterioration of resolving power with a geometric correction by receiving the complex number data after processing of a data compressing part as input and making the geometric correction in accordance with the suitable geometric coordinate transformation equation.

CONSTITUTION: A raw data input part 1 takes the raw data on the synthetic aperture radar into the device and sends the same to the data compressing part 2 which compresses the raw data 11 by correlative processing and forms image data 23. The geometric correction part 3 subjects the image data 23 obtd. in the part 2 to the geometric correction in accordance with the prescribed geometric coordinate transformation equation in the state of the data of the complex type and converts the same to image data 33. A multi-look circuit 4 decreases the speckle noise incorporated into the data 33 subjected to the geometric correction in the complex region and converts the complex number data to real number data. The image data is thereupon displayed on an image display 51 of an image processing part 5 and is recorded on a magnetic tape medium in a magnetic tape circuit 52.