Light emitting diode as sensor for miniature multispectral radiometer

A methodology is proposed for studying the suitability of the light emitting diode (LED) as the optical sensor of a miniature multispectral radiometer. The optoelectronic properties of three commercially available LEDs of three different wavebands were standardized by measuring the open-circuit voltage and short-circuit currents at different light intensities and different wavelengths of incident radiation. A photoconductive measurement was found to be more useful for obtaining the appropriate optical response and was suggested as the suitable mode of sensing. The sensor performances were demonstrated for both solar photometry and surface reflectance measurements.