New reference sources for radiometric calibration

Reference light sources are key devices in a radiometric calibration system. To meet the calibration requirements of recently developed opto-electronic sensors with various spectral resolutions and operation modes, reference light sources are required to possess new functions such as spectral match, large dynamic adjustment range, fine scanning in wide spectrum, as well as the basic features such as high stability and uniformity. This paper gives a brief introduction of the design features, main performances and initial applications of a spectrally adjustable light source based on LED modules and a wide spectrum tunable monochromatic planar light source based on tunable lasers. Incorporated with detector-based transfer standards, these new reference light sources can meet specific calibration requirements and improve absolute calibration accuracy.