On-board non-uniformity correction calibration methods for microbolometer focal plane arrays

A method of calibrating a microbolometer focal plane array (MFPA) having detector elements and that reside in a thermal camera that has a processing unit that is operably coupled to an external computer and a shutter, comprising:

• performing first calculations in the processing unit to generate a set of coarse correction bias voltages;
• applying the coarse correction bias voltages to the detector elements;
• collecting image data with the coarse correction bias voltages applied to the detector elements;
• performing second calculations in the external computer based on the image data collected by the thermal camera to generate a set of fine gain and fine offset correction values;
• downloading the fine correction values;
• and
• applying the fine correction values to the detector elements to establish a fine calibration of the MFPA;
• wherein performing first calculations is repeated at a plurality of ambient temperatures to calculate a plurality of coarse correction tables corresponding to various ones of the ambient temperatures, and wherein performing second calculations includes calculating fine correction values to create a plurality of fine correction tables corresponding to the various ones of the ambient temperatures.

A method of calibrating a microbolometer focal plane array (MFPA) having detector elements and that reside in a thermal camera that has a processing unit that is operably coupled to an external computer and a shutter, comprising:

• performing first calculations in the processing unit to generate a set of coarse correction bias voltages;
• applying the coarse correction bias voltages to the detector elements;
• collecting image data with the coarse correction bias voltages applied to the detector elements;
• performing second calculations in the external computer based on the image data collected by the thermal camera to generate a set of fine gain and fine offset correction values;
• downloading the fine correction values;
• and
• applying the fine correction values to the detector elements' output signals to establish a fine calibration of the MFPA;
• wherein:
• performing first calculations includes calculating detector non-uniformity corrections (NUCs);
• and
• collecting image data includes:
• collecting image data DL1 at a first ambient temperature and image data DH1 at a first calibration source temperature;
• and
• collecting image data DL2 at a second ambient temperature and image data DH2 at a second calibration source temperature, wherein the NUCs and image data DL1 are sent to the external computer before image data DH1, DL2, and DH2 are obtained.