Technology advancements and concepts for IR grating spectrometer sounders for CubeSats and SmallSats at NASA JPL

Hyperspectral infrared sounding of the atmosphere has become a vital element in the observational system for weather forecast prediction at National Weather Prediction (NWP) centers worldwide. The NASA Atmospheric Infrared Sounder (AIRS) instrument was a technology and science demonstration of hyperspectral infrared observations and was designed to provide accurate atmospheric temperature and water vapor profile information in support of weather prediction. AIRS was launched in 2002 and continues to operate well today. The cost of AIRS was substantial, and has created the need to explore lower cost alternatives for the post-JPSS era. The high cost of AIRS and other legacy IR sounders prevents them from being launched into multiple orbits to improve temporal sampling.

JPL, with government and industry support, has led the development of grating spectrometer hyperspectral IR sounder technologies for the future including large format focal plane assemblies, wide field optics, immersion gratings, black silicon blackbodies, and active cryocoolers that enable a reduction in size, mass and cost of the legacy sounders. This technology has enabled JPL to begin development of a CubeSat Infrared Atmospheric Sounder (CIRAS). CIRAS employs only an MWIR spectrometer to achieve lower tropospheric temperature and water vapor profiles, but with comparable spatial, spectral and radiometric sensitivity in this band as AIRS and CrIS.

This presentation will discuss the status of the AIRS instrument after 17 years in orbit and the state-of-the-art in grating spectrometer IR sounder technology since AIRS and the CubeSat and SmallSat concepts JPL has developed that use this technology for future meteorological and research applications.