Auroral height-measuring system designed for real-time operation

• Published in: Review of Scientific Instruments
• Main Author: Steen, Åke
• Format: Article in Journal/Newspaper
• Language: English
• Published: AIP Publishing 1988
• Subjects: Kiruna
• Online Access: http://dx.doi.org/10.1063/1.1139989; https://pubs.aip.org/aip/rsi/article-pdf/59/10/2211/19036967/2211_1_online.pdf

The altitude and altitude distribution of auroral emissions, such as the [N+2] λ427.8-nm emission, are one result of processes in the ionosphere and magnetosphere during periods of auroral activity. A bistatic height-measuring system (HMS) has been developed with the primary objective of determining the altitude and latitude of auroral emissions in the magnetic meridian plane through Kiruna, Sweden. Since significant morphological redistributions occur in the aurora within a few seconds, HMS was designed to measure auroral altitudes with a time resolution of 1.5 s. The base line between the two stations was short (13 km), which generated similar-looking meridian profiles of the measured auroral emissions. The meridian profiles were obtained with intensified photodiode arrays, operated in a monochromatic imaging mode. The hardware and software configurations of HMS and essential assumptions for the triangulation procedure are described. HMS is especially adapted to measure during periods of disturbances in auroral arcs, e.g., eastward-traveling folds. The estimated optimal accuracies of the determinations of the latitudinal position of an auroral arc and the altitude of an identified auroral point are ±0.01° and ±1 km, respectively.