Title of Presentation: Tropospheric Infrared Mapping Spectrometers (TIMS) for CO Measurements With Much Improved Vertical, Temporal and Spatial Resolution, Especially in the Lower Troposphere by Utilizing Both the 2.3 and 4.7 µm Regions
Primary (Corresponding) Author: John (Jack) B Kumer
Organization of Primary Author: Lockheed Martin Advanced
Co-Authors: A.E. Roche, R.L. Rairden, J.L. Mergenthaler and R.B. Chatfield
Abstract: The recently released report of the National Research Council " Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond" describes requirements for improved atmospheric measurements to gain crucial understanding for air quality, climate change, and weather. Improved vertical and horizontal resolution, temporal resolution and coverage are required. Our project is focused on demonstrating a technology; Tropospheric Infrared Mapping Spectrometers (TIMS) that would provide considerably improve measurements of CO, commensurate with the NRC report requirements. Nadir radiance acquired at high spectral resolution, the order a few tenths cm-1, in the regions of the CO bands near 2.3 µm (solar reflective, SR) and 4.7 µm (thermal emissive, TIR), together with the low noise design (signal photon statistics dominated) would provide for CO retrieval with improved vertical information, in three independent layers including the lowest several km layer. For LEO deployment the data are acquired on contiguous footprints the order 2 km (SR)and 4 km (TIR) at nadir, and swath widths the order 2800 km providing daily global coverage in the SR and twice daily in the TIR. In GEO deployment coverage area is traded for increased temporal resolution, e.g., several 1000 km on a side, repeatedly per hour. The primary measurement goal is CO, but the spectra contain information that facilitates retrieval of column CH4, and H2O partial columns including considerable improvement in the boundary layer. The technology uses low noise 2D arrays fed by a grating spectrometer. There are no moving parts. The design is compact. This facilitates, if desired, added spectral regions for measurements of additional species , e.g., tropospheric ozone partial columns in the 9.6 um band and/or CO2 column in a band near 2.1 µm. We will present the TIMS instrument and measurement concept, its heritage, ouyr demonstration appraoch, and preliminary test results.