Space systems: An auroral imaging spectrophotometer (vacuum ultraviolet and visible)

An imaging system is described that will provide spectrophotometric data of the Earth's aurora from a satellite-based platform. The instrument has two camera heads, one operating in the vacuum ultraviolet (12.0 to 200.0 nm) spectrum, the other operating in the visible/near ultraviolet (300.0 to 750.0 nm) spectrum. The camera heads are equipped with a variety of spectral bandfilters that are selectable from a filter wheel to define the auroral spectral band of interest. Each camera has a collapsible sunshade that is deployed after spacecraft launch. An illumination sensor is included to provide solar damage protection. Separate processing electronics exist for each camera head, but they are switchable between heads to provide selective redundancy. Each camera head uses the most recent developments in microchannel plate image intensifiers in conjunction with solid-state two-dimensional matrix sensors.