Auroral all-sky camera calibration

• Published in: Geoscientific instrumentation, methods and data systems Vol. 3; no. 2; pp. 241 - 245
• Main Authors: Sigernes, F, Holmen, S. E, Biles, D, Bjørklund, H, Chen, X, Dyrland, M, Lorentzen, D. A, Baddeley, L, Trondsen, T, Brändström, U, Trondsen, E, Lybekk, B, Moen, J, Chernouss, S, Deehr, C. S
• Format: Journal Article
• Language: English
• Published: Gottingen Copernicus GmbH 10.12.2014; Copernicus Publications
• ISSN: 2193-0864; 2193-0856; 2193-0864
• DOI: 10.5194/gi-3-241-2014

A two-step procedure to calibrate the spectral sensitivity to visible light of auroral all-sky cameras is outlined. Center pixel response is obtained by the use of a Lambertian surface and a standard 45 W tungsten lamp. Screen brightness is regulated by the distance between the lamp and the screen. All-sky flat-field correction is carried out with a 1 m diameter integrating sphere. A transparent Lexan dome at the exit port of the sphere is used to simulate observing conditions at the Kjell Henriksen Observatory (KHO). A certified portable low brightness source from Keo Scientific Ltd was used to test the procedure. Transfer lamp certificates in units of Rayleigh per Ångstrøm (R/Å) are found to be within a relative error of 2%. An all-sky camera flat-field correction method is presented with only 6 required coefficients per channel.