TIMED Instruments

he Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) mission is providing a core set of measurements defi ning the basic states of the mesosphere and lower thermosphere/ionosphere (MLTI) region (approximately 60–180 km above the Earth’s surface) and its global energy balance. This article discusses the TIMED spacecraft’s suite of four remote sensing instruments designed to observe the parameters that defi ne the atmospheric basic state and energy inputs and outputs in the MLTI. The Global Ultra-Violet Imager (GUVI) is a spatial scanning far-ultraviolet spectrograph that measures composition and temperature in the lower thermosphere, as well as auroral energy inputs. The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument is an infrared radiometer that measures pressure, temperature, and infrared cooling rates in the stratosphere, mesosphere, and lower thermosphere. The Solar Extreme Ultraviolet Experiment (SEE) is a spectrometer and a suite of photometers measuring incoming solar irradiance. The TIMED Doppler Interferometer (TIDI), a Fabry-Perot interferometer, measures horizontal vector winds and composition in the mesosphere and lower thermosphere.