AIRS Level-1C and applications to cross-calibration with MODIS and CrIS

Abstract

We introduce and illustrate applications of the AIRS Level-1C (L1C) data product. While each spectrum in the Level- 1B (L1B) calibrated radiances is represented by 2378 channels, each spectrum in the L1C product is represented by 2645 channels, with monotonically increasing frequency. Typically 2000 of the 2378 L1B channels are copied unchanged into the 2645 channel array used in L1C. The dead or noisy channels in the L1B and new channels in the spectral gaps of L1B are filled using a Principal Component technique. We illustrate two applications of AIRS L1C: 1) to integrate over the band of broadband instruments such as MODIS and 2) resampling to emulate other hyperspectral instruments such as CrIS. The L1C data product will greatly facilitate the use of AIRS data for cross-calibration with other instruments.