Nightglow studies at Onera for night-vision applications

Since 2010 Onera works on the characterization of the nightglow radiation for night-vision applications in moonless conditions. This radiation is mainly due to the deexcitation of hydroxyl molecules in the upper atmosphere (similar to 87km). It is present in the visible range and reaches its maximum value in the short wavelength infrared bands between 1.4 and 1.8 mu m (Meinel bands). Although few energy reaches the ground, this radiation is emitted over the whole sky and therefore may be an interesting additional light source for night vision systems in moonless or cloudy sky conditions. Moreover, observation of the nocturnal sky in the short wave infrared band gives access to dynamic processes studies, these processes perturbing emission of radiation. In this paper, we present works carried out at Onera about observation and modelling of nightglow radiation.