Ultraviolet imaging from space of the aurora under full sunlight

Abstract

This report presents the first successful global‐scale auroral images in full daylight. The vacuum ultraviolet (VUV) imager on board the recently launched HILAT satellite has demonstrated that clear images of the global auroral display over the local summer polar region under full sunlight conditions can be obtained, indicating that the earth’s albedo and dayglow background are not formidable obstacles to the global auroral imaging at the VUV wavelengths (135.6 ± 1.5 nm and 149.3 ± 1.5 nm). Some of the images of dayglow and auroras in daylight are presented and discussed.