THERMAL INFRARED IMAGING SYSTEM AND ASSOCIATED METHODS FOR RADIOMETRIC CALIBRATION

摘要

A thermal infrared (IR) imaging system and associated calibration methods are described. In various illustrative embodiments, techniques are provided for the stabilization and radiometric calibration of a thermal IR imager without stabilization of the device's focal-plane-array (FPA) temperature. In one embodiment, a scene image is corrected for FPA temperature to produce a FPA-temperature-stabilized image, to which radiometric calibration can optionally be added through additional calculations and prior device characterization. In another embodiment, the internal shutter of the thermal IR imager is used as an equivalent external blackbody source to cancel the FPA-temperature-dependent offset from a scene image Radiometric calibration can be included through additional calculations and prior device characterization. In some embodiments, these techniques are combined to correct for dependence on FPA temperature of both the imager's responsivity and its zero-radiance-scene offset.