Use of Atmospheric Infrared Sounder high–spectral resolution spectra to assess the calibration of Moderate resolution Imaging Spectroradiometer on EOS Aqua

Abstract

[1] AIRS and MODIS on the EOS Aqua spacecraft collect global observations of the Earth's upwelling infrared radiance for numerous remote sensing and climate related applications. This paper presents comparisons of the AIRS and MODIS radiance observations and illustrates the utility of using high-spectral resolution observations to create a highly accurate assessment of broadband sensor calibration. In the analysis, the high-spectral resolution AIRS spectra are reduced to MODIS spectral resolution, and the high-spatial resolution MODIS data are reduced to AIRS spatial resolution for global data collected on 6 September 2002 and 18 February 2004. Spatially uniform scenes are selected, and the observed differences are characterized as a function of several parameters including scene temperature, sensor scan (view) angle, and solar zenith angle. The comparisons are in general very good with respect to the expected radiometric accuracies of the sensors, with mean brightness temperature differences of 0.1 K or less for many of the MODIS bands. Uncertainties of these determinations range from near 0 K for window region bands to as large as 0.2 K for other bands. For MODIS water vapor bands 27 (6.8 mm) and 28 (7.3 mm) and temperature sounding bands 34 (13.7 mm), 35 (13.9 mm), and 36 (14.2 mm), the differences exhibit a dependence on scene temperature, with peak differences exceeding 1 K for bands 27 and 36. Differences as a function of scan angle are 0.4 K or less for all bands, and scan angles but clear trends are defined. Results for the 2 days demonstrate good reproducibility with changes in mean differences of 0.1 K or less for most bands.

Resolving ice cloud optical thickness biases between CALIOP and MODIS using infrared retrievals

“…The calibration of the IR channels has been extensively validated and proven to have high accuracy, with uncertainties less than 0.5 K across a broad temperature range (Tobin et al, 2006). For ice clouds, the IR radiative transfer is dominated by absorption, and thus is less complex than for the VNIR retrieval.…”

Atmospheric parameters in a subtropical cloud regime transition derived by AIRS and MODIS: observed statistical variability compared to ERA-Interim

“…Combining the information obtained from the two sensors has resulted in advances in cross-sensor radiance calibration (Tobin et al, 2006;Schreier et al, 2010), synergistic multi-sensor cloud property retrievals (Li et al 2004a, b) and cloud phase characterization (Kahn et al, 2011a). It is also a useful source of information for radiative transfer calculations under cloudy conditions (Ou et al, 2013) and offers a promising basis for improvements in thermodynamic profile sounding (e.g., Maddy et al, 2011).…”

Inter-Comparison of S-NPP VIIRS and Aqua MODIS Thermal Emissive Bands Using Hyperspectral Infrared Sounder Measurements as a Transfer Reference

“…A number of approaches are used to independently track the performance of Aqua MODIS (hereafter MODIS) Level 1B TEB, which includes reference to near-surface temperature observations over Dome Concordia, Antarctica [8], comparison of the simultaneous nadir overpasses (SNO) measurements with the Infrared Atmospheric Sounding Interferometer [9] and the Atmospheric Infrared Sounder (AIRS) [10,11]. VIIRS on-orbit calibration methodology and early performance has been reported in several studies [12][13][14].…”