Abstract: An image mapping radiometer mounted on a craft flying an orbit above an object zone. The radiometer includes main optics having in the visible field thereof a unit object zone defined by the swath width over the object zone and a distance in the direction of orbit, and a plurality of linear photoelectic detectors each being assigned to one of a plurality of observation spectral bands and located in the focal plane of the main optics, thereby sequentially imaging the unit object zone. A correcting section has correction optics for projecting a correction pattern onto the photoelectric detectors so as to correct the band-to-band registration, i.e., the positional deviation between the elements of the detectors. A movable mirror is provided for selecting either of the main optics and correction optics. When the correction pattern is projected, a lattice pattern having a pitch different from the element pitch is generated on the light-sensitive surfaces of the detectors.

Abstract: A radiometer mounted on an aircraft, satellite or similar flying body for observing reflections or radiations of visible rays or infrared rays from the land or the sea. The radiometer has optical means for receiving and converging the visible rays or infrared rays, light-sensitive elements to which the converged rays are incident, means for changing the optical distance between the light-sensitive elements and the optical means, and means for generating correction data while the focal distance of the optical means is deviated from the light-sensitive surface of the light-sensitive elements.