High Resolution Dynamics Limb Sounder
HIRDLS MISSION OVERVIEW
The High Resolution Dynamics Limb Sounder (HIRDLS) instrument was designed to provide measurements of temperature, trace constituents and aerosols from the middle troposphere to the mesosphere, with key attributes of global sampling at high vertical and high horizontal resolution. The high horizontal resolution was to be achieved by making vertical scans at several azimuths across the satellite orbit track. Shortly after launch, a blockage over most of the aperture was discovered. Due to this blockage, HIRDLS has lost the ability to scan horizontally, but will still be able to make atmospheric measurements at one azimuth, with nearly global coverage on a daily basis. High vertical resolution measurements remain a key attribute for HIRDLS, and indeed HIRDLS observations at one azimuth will provide information on vertical scales that are unavailable from other Aura instruments. HIRDLS will measure a number of atmospheric constituents that are part of its original set of objectives. HIRDLS will also provide key measurements of atmospheric aerosols and cirrus clouds, as well as unique measurements of sub-visible cirrus.