Thermosphere Ionosphere Mesosphere Energetics and Dynamics (12/2001-present)

TIMED is a mission to investigate and understand the energetics of the Mesosphere and Lower-Thermosphere/Ionosphere (MLTI), the region in the Earth's atmosphere from about 60 to 180 km in altitude. The measurements of TIMED will provide data defining the basic states of the MLTI region and its thermal balance.  TIMED has four instruments. The Global Ultraviolet Imager (GUVI) is a spatial-scanning, far-ultraviolet spectrograph designed to globally measure the composition and temperature profiles of the MLTI region, as well as its auroral energy inputs. The Solar Extreme Ultraviolet Experiment (SEE) is comprised of a spectrometer and a suite of photometers designed to measure the solar soft X-rays, extreme-ultraviolet and far-ultraviolet radiation that is deposited into the MLTI region. The TIMED Doppler Interferometer (TIDI) is designed to globally measure the wind and temperature profiles of the MLTI region. A multichannel radiometer known as SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) is designed to measure heat emitted by the atmosphere over a broad altitude and spectral range, as well as global temperature profiles and sources of atmospheric cooling.

The solar measurements from SEE cover the full-disk solar irradiance from 0.1 to 200 nm using a grating pectrograph and silicon photodiodes coated with thin film transmission filters. The spectral resolution of the measurements is 0.4 nm above 25 nm and about 7 nm below 25 nm. SEE was designed and built primarily by LASP at University of Colorado, under contract with NASA.