Technology Maturation Efforts for the Next Generation of Grating Spectrometer Hyperspectral Infrared Sounders

Abstract

As we look forward to the next generation of hyperspectral infrared (IR) atmospheric sounders, grating spectrometers hold promise for improved performance (e.g., horizontal and spectral resolutions) and more rapid revisit while reducing the size and complexity of the instrument. We briefly revisit the technology used in the Atmospheric Infrared Sounder (AIRS), recognizing that it was developed in the 1990's and has matured key technologies in the areas of IR detectors, optical coatings, gratings, and cryocoolers. AIRS has been an unqualified success not only as a science and operational mission but also as a technology demonstration of the reliability and simplicity of grating spectrometer IR sounding instruments. Advancements in focal plane arrays (FPAs) have enabled a new class of grating spectrometer IR sounders that offer more spectral channels on a single FPA, mitigating some of the issues seen in AIRS that used linear arrays. These improvements have been manifested in the CubeSat Infrared Atmospheric Sounder (CIRAS) brassboard instrument, developed at the California Institute of Technology Jet Propulsion Laboratory with industry partner Ball Aerospace. Further enhancements beyond those used in CIRAS enable the development of a new class of instruments with a very long-wavelength infrared response and a very high spatial resolution (<2 km) that can be used for the next generation of IR sounders. Grating spectrometers provide advantages over other methods, including smaller apertures due to the ability to use larger FPAs, having no moving parts or laser metrology systems to produce spectra, lower internal FPA readout rates, and lower overall system data rates.

The Earth‐Observing Aqua Satellite Mission: 20 Years and Counting

“…( 2003 ) and in Pagano et al. ( 2022 ), the latter also including the technology efforts aimed at the next generation of grating spectrometer infrared sounders.…”

“…Furthermore, each AIRS detector has a redundant backup, in case the primary detector fails, and the detectors are maintained at a stable temperature through an innovative cryocooler, resulting in the high level of stability that enables AIRS data to be used to accurately determine signals of climate change. More information on the AIRS instrument can be found in Aumann et al (2003) and in Pagano et al (2022), the latter also including the technology efforts aimed at the next generation of grating spectrometer infrared sounders.…”