Performance of the Multispectral Photoconductive HgCdTe Focal Plane/Dewar Assembly for the High Resolution Dynamics LImb Sounder (HIRDLS) Instrument

摘要

The HIRDLS instrument is part of the Chemistry Platform for NASA's Earth Observing System (EOS) Program. This infrared limb-scannign radiometer is designed for sounding the upper troposphere, stratosphere and mesophere at multiple azimuth angles to measure CO_2, O_3, H_2O, aerosols and other greenhouse trace gases in the 6.12 to 17.76 mum band. Spectral coverage is provided by a Focal Plane Asembly (FPA) consisting of 21 individual n-type HgCdTe photoconductive detectors whose cutoff wavelengths are selected to optimize sensitivity when operated in conjuction with individual bandpass filters mounted in close proximity. Near-BLIP sensitivities and highly linear response are required to achieve the science objectives. The FPA is integrated into a unique vacuum dewar that utilizes a sapphire rod interface to a mechanical cryocooler to operate the FPA at 65 K.