Abstract

Variations in ground irradiance at frequencies higher than 0.1 Hz may severely degrade the performance of automatic imaging systems. For this reason measurements and analysis of fast variations in ground irradiance in the auroral region due to variable auroral emissions have been performed. The largest amplitudes and fastest variations are found to occur during the active phase of geomagnetic substorms and during pulsating auroral conditions, respectively. The power spectra of the variations show a rapid decrease toward higher frequencies. Pulsating auroral conditions contain more power at higher frequencies than do the active phase. On the average ~10% of the total power in the spectra is at frequencies higher than 0.3 Hz.

© 1984 Optical Society of America

Nocturnal ground irradiance at high latitudes

Hans K. Myrabø
Appl. Opt. 24(22) 3908-3913 (1985)

Absolute Calibration of Auroral Photometers and Ground-Based Measurements in the 3200–7500-Å Spectral Region

Kjell Henriksen
Appl. Opt. 13(5) 1196-1201 (1974)

Influence of ground scattering on satellite auroral observations

P. B. Hays and C. D. Anger
Appl. Opt. 17(12) 1898-1904 (1978)

Nocturnal levels of ground illuminance in auroral regions

H. K. Myrabø
Appl. Opt. 21(11) 1881-1882 (1982)

Cinematography of Spatial and Temporal Variations in Auroral Forms with an Image Orthicon TV System

Grady T. Hicks and T. Neil Davis
Appl. Opt. 4(2) 187-188 (1965)