Dr. Christian A. Gueymard, one of the partners of LuciSun, is a renowned expert in solar radiation and energy meteorology. He developed the Simple Model of the Atmospheric Radiative Transfer of Sunshine (SMARTS), widely used for simulating spectral solar irradiance under diverse atmospheric conditions, and the Radiation Enhancement Simulation Tool (REST), which evaluates cloud-induced radiation enhancements. His contributions have advanced the accurate assessment of solar radiation, improving the performance analysis of photovoltaic systems.