ALIS, Auroral Large Imaging System

ALIS consists of unmanned imaging stations located in Northern Scandinavia in a grid of about 50×50 km. Each station is equipped with an imager having a high-resolution monochrome 1024×1024 pixel CCD detector and a filter wheel with six positions for narrow-band interference filters. The field of view is 70 degrees diagonally for most imagers, but there are also two units with a 90 degrees field of view. The imagers are mounted in a positioning system and can be pointed so that several imagers can view a common volume. ALIS is operated on campaign basis. Filter sequences and pointing directions are freely selectable.