C. D. Anger

Intensified Charge-Coupled-Device Imager For Auroral Studies

A 100 X100 pixel charge-coupled-device (CCD) area detector combined with an image intensifier, all-sky optics, and a filter wheel has been developed to provide quantitative monochromatic images of the aurora. The design of the instrument provides for a variable exposure rate to accommodate the large dynamic range of auroral intensities, from a minimum of 20 ms up to several minutes. Standard auroral emission features are monitored by four selectable filters, normally at 6300, 5577, 3914, and 4278 A. Depending on the filter utilized, sensitivity can be from 180 to 250 R ADU-1 s-1. The instrument has been used successfully in support of balloon, rocket, and satellite campaigns.

An All-Sky Imaging Photometer

A versatile optical instrument capable of all-sky auroral imaging at low light levels is described. The All-Sky Imaging Photometer uses as a detector an image dissector photomultiplier tube operating in a photon-counting mode. A miniprocessor interprets commands entered interactively by the operator through a terminal, and controls data acquisition and display. A motorized filter wheel holding up to six interference filters permits monitoring of auroral emis-sions at monochromatic wavelengths.