PURPOSE: To make it possible to simultaneously correct display corresponding to the change in a visual field following rolling and image distortion following a visual angle, by changing a sampling interval in correspondence with the detection signal of the rolling angle of a flight body.

CONSTITUTION: The inclination degree of the flight body from a gyrocompass to ground line is inputted to MPU9 while converted by an A/D converter 8 and MPU9 calculates the address start value of ROM11 corresponding to inclination degree information while allows a counter 10 to store the start value of ROM11 corresponding to the start signal of the horizontal synchronous signal from an infrared camera 2 and allows a counter 5 to input modulation data from ROM11. The counter 5 applies the corresponding sample clock to an A/D converter 4 and the converted output of the camera 2 is stored in image data memory 14. The writing region of the memory 14 is enlarged for the sake of rolling correction. A reading start value is inputted to an address generating circuit 15 from MPU9 and horizontal reading is performed on the basis of the corresponding address value in a vertical direction while an image corresponding to a visual field changing by rolling is displayed.