TIDI Science Team, Space Physics Research Laboratory, University of Michigan
Data Center Description
The TIMED Doppler Interferometer (TIDI) is investigating the dynamics and energetics of the Earth's mesosphere and lower-thermosphere. TIDI measurements allow us to obtain a global description of the vector wind fields, as well as important information on gravity waves, species densities, airglow and auroral emission rates and noctilucent clouds. TIDI provides basic information about global winds. TIDI also contributes to the study of energetics.
The TIDI interferometer (or Profiler) primarily measures horizontal vector winds from the Earth's limb, with a vertical resolution 2.5 km and with an accuracy that approaches ~3 m/sec under optimum viewing conditions. The TIDI design allows for 100% duty cycle instrument operation during daytime, nighttime, and in auroral conditions. TIDI views emissions from OI 557.7 nm and O2(0-0) to determine Doppler wind.
TIDI comprises three major subsystems: four identical telescopes, a Fabry-Perot interferometer with a CCD detector, and an electronics box. Light from the selected regions of the atmosphere is collected by the telescopes and fiber-optically coupled to the detection optics. The four fields of view are scrambled along with a calibration field input and converted to an array of five concentric circular wedges. This input then passes through a selected filter, then through a Fabry-Perot etalon, and is finally imaged onto a CCD via a circle to line imaging optic (CLIO) device.