|Laboratory spectral and radiometric calibrations are
performed by OKSI on all EO/IR sensors covering the spectrum from the
visible to the long wave infrared.
Radiometric calibration sources typically used include NIST traceable irradiance lamps and blackbodies.
Infrared calibration is often performed with nitrogen purge to remove
the absorption by CO2 and H2O in the air. This provides a true response
of a sensor over its entire range.
Spectral calibration is performed using a variety of lasers and gas
discharge lamps (e.g., He, Ar, Kr, Hg, etc.). Spectral calibration in
the infrared is performed using band pass filters.
As necessary, the calibration set up uses integrating
spheres and collimators to assure repeatability. Multiple sources are often used simultaneously
and injected directly into a collimator or an integrating sphere.