Freeform reflector design for uniform illumination in a space-based remote sensor calibration system

Abstract

A freeform reflector for illumination in a space-based remote sensor calibration system is designed to produce the desired patterns and improve efficiency. Owing to the excellent cosine properties and light source stability of the integrating sphere, it is widely used as the calibration source in optical remote sensing instruments. However, the light source cannot obtain uniform illumination on a large scale. Therefore, we propose a freeform reflector design for an integral sphere source, which generates an independent irradiance distribution and achieves large-scale illumination by arraying. The irradiance uniformity and efficiency obtained were greater than 98% and 90%, respectively.