keogram

plural keograms

1. A photographic method of capturing aurorae.

   A ewogram is similar to a keogram except that the vertical axis is magnetic longitude instead of magnetic latitude for a keogram.

   2011 June 21, William Liu, Masaki Fujimoto, “Part II Magnetotail Dynamics”, in The Dynamic Magnetosphere, illustrated edition, volume 3, Springer Science & Business Media, →ISBN, page 79

   4 more examples

   Various types of data formats can be obtained starting with the digitized data. One currently being used in combination with magnetospheric studies is the "keogram" picture⁽⁴⁾. This technique combines each intensity versus zenith angle scan on a horizontal time axis.

   1976, Douglas P. McNutt, Society of Photo-optical Instrumentation Engineers, Methods for Atmospheric Radiometry, August 26-27, 1976, San Diego, California, illustrated edition, volume 91, SPIE, →ISBN, page 69

   A diagram of the latitudinal variations with time is sometimes called a keogram. Neither scanning photometers nor cameras are sufficiently sensitive to record the most rapid fluctuations in the auroral emissions, but TV techniques, both monochrome and color, are more sensitive and have been applied very successfully to dynamic auroral photography in recent years. In addition to their scientific value, some of these auroral "videos" are possessed of no little esthetic interest (particularly if they are set to music). Figure 6.9 shows an example of a keogram composed from TV data.

   2007 September 10, R. D. Hunsucker, J. K. Hargreaves, “Chapter 6 The aurora the substorm and the E region”, in The High-Latitude Ionosphere and its Effects on Radio Propagation, Cambridge University Press, →ISBN, page 300

   In this paper we argue that the photometric keogram technique is more reliable and more accurate than all-sky cameras for cusp monitoring, and gives minute-by-minute time resolution not possible with satellite data.

   2012 December 6, Syun-Ichi Akasofu, “Dayside Aurora A Signature of the Dayside Cusp”, in Dynamics of the Magnetosphere: Proceedings of the A.G.U. Chapman Conference ‘Magnetospheric Substorms and Related Plasma Processes’ held at Los Alamos Scientific Laboratory, Los Alamos, N.M., U.S.A. October 9–13, 1978, illustrated edition, volume 78, Springer Science & Business Media, →ISBN, page 123

   Observation and classification results from the night of 22–23 October 2017. The middle panel shows a keogram, which is a time series of the north-south cross-section of the all-sky image, and the bottom panel is the classification result for the same period.

   2022 May 31, Sota Nanjo, et al., “An automated auroral detection system using deep learning: real-time operation in Tromsø, Norway”, in Nature, archived from the original on 03 Feb 2024