Absolute radiometric calibration of the DAIS-7915 thermal channels using sub-pixel targets

Utilization of sub-pixel targets for radiometric calibration of airborne and space-borne imaging sensors involves the uncertainty of their contribution to the pixel-integrated radiance. This contribution depends not only on the target area but also on an unknown location of the sub-pixel target within a sensor pixel. A technique is proposed to retrieve both the target radiance and its sub-pixel location from the target image, taking into account the effects of the sensor point spread function. The technique was used for in-flight calibration of the thermal channels of the airborne imaging spectrometer DAIS-7915.