RADIOMETRIC PERFORMANCE ENHANCEMENT OF EXTENDED AREA BLACKBODIES

摘要

An extended area “cavity type” blackbody for use as a radiometric reference for imaging systems may have a well in the form of a cube having four sidewalls and a back wall, and open at the front. The temperature of the back wall may be controlled independently of the temperature(s) of the sidewalls. This system may produce infrared radiance closer to an ideal radiator than typical extended area sources. A “simple” blackbody is disclosed, having a source plate with a front emitting surface; a ledge element disposed in front of and below the source plate for heating air in front of the source plate; and (optionally) another ledge element disposed in front of and above the source plate for cooling air in front of the source plate. A housing may support the source plate and ledge element, and a vent may be provided in front of and above the source plate. A resistive heater may be associated with the ledge element; and (optionally) TECs may be associated with the other (cooling) ledge element. Angles of the ledges may be adjustable to optimize the best uniformity for a particular implementation. Temperature control of the ledges may be in unison with or independent from the source plate.