In this visualization, we present GOLD (in geostationary orbit around Earth) and ICON (in low Earth orbit). The colors over Earth represent model data from the IRI (International Reference Ionosphere) model of the density of the singly-ionized oxygen atom at an altitude of 350 kilometers. Red represents high density. The ion density is enhanced above and below the geomagnetic equator (not perfectly aligned with the geographic equator) on the dayside due to the ionizing effects of solar ultraviolet radiation combined with the effects of high-altitude winds and the geomagnetic field.
In the latter half of the visualization, the viewing fields of the various instruments are displayed. ICON has an EUV (Extreme Ultraviolet) and FUV (Far Ultraviolet) cameras (violet colored frustrums directed from spacecraft) pointing perpendicular to the orbit direction for detecting ionospheric emissions. Two Doppler interferometer cameras (blue) are directed at 45 degrees from this camera to detect ionospheric wind velocities.
GOLD has an imaging spectrometer (green) that periodically scans the disk of Earth with additional higher-resolution scans of the dayside limb.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0