Inter-comparison of the longwave infrared channels of MODIS and AVHRR/NOAA-16 using simultaneous nadir observations at orbit intersections

Abstract

Near nadir observations in the 11µm and 12 µm bands of the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the TERRA spacecraft and the Advanced Very High Resolution Radiometer (AVHRR) onboard the NOAA-16 spacecraft are collected at their orbit intersections, where both MODIS and AVHRR view the Earth and its atmosphere at the same location within 30 seconds in the Arctic region. Sample data with 1 km resolution from spatially uniform areas are taken for direct inter-comparison of the scene radiance and brightness temperatures at around 270 K. Then a pixel-by-pixel match between the MODIS and AVHRR observations is performed to evaluate their correlation at different scene temperatures. The results show that MODIS and AVHRR observations agree well (difference less than 0.3 K) for both the 11µm and 12 µm bands, although their band correlation exhibits a slightly non-linear trend for scene temperatures greater than 285 K. The performance of MODIS is considered a good predictor of the performance of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) /Visible Infrared Imager/Radiometer Suite (VIIRS), the future replacement of AVHRR. The direct comparison of MODIS and AVHRR observations is therefore considered a risk reduction study for VIIRS.

Assess Calibration Consistency of MODIS and AVHRR Thermal Infrared Bands Using SNO Observations Corrected for Atmospheric Effects

“…The independent calibration of thermal bands between MODIS and AVHRR provides a valuable quality assessment of the performance of each instrument. A direct comparison of temperature obtained from near-simultaneous nadir overpasses (SNOs) shows that the differences are generally within 0.25 K at typical scene temperatures for the atmospheric window bands [8]- [10]. A clear dependence of the temperature difference on scene temperature has been found between MODIS and AVHRR and for most pairs of NOAA series AVHRR [11].…”

“…noaa.gov/oaJpod-guide/ncdc/docsJintro.htm), while coefficients for Terra and Aqua MODIS are derived using the same procedure [8), [9), [13). Basically, coefficients A and B are determined from the linear regression between TE and T, with T changing from 180 K to 320 K at an interval of 0.1 K. The theoretical value of TE is computed by convolving the RSR with the BB spectral radiance at T. The relative difference in T between MODIS and AVHRR is calculated by (3) where TMoDIS and TAVHRR are the effective temperatures for MODIS and AVHRR, respectively.…”

The International Satellite Cloud Climatology Project H-Series climate data record product

“…overall IR calibration adjusted for small gain error in AVHRR calibrations compared to MODIS for all AVHRRs on NOAA-15 and onward (Cao and Heidinger, 2002). …”

10. The Calibration and Characterization of Earth Remote Sensing and Environmental Monitoring Instruments

“…Frequent near nadir coincident views of snow, ice, and open ocean near the north and south poles by polar orbiting satellites have also been used in instrument crosscalibrations [259]. Examples of instruments cross-calibrated using these scenes include the 11 pm and 12 pm bands on MODIS and the AVHRRs on NOAA-16 [260] and the visiblehear infrared channels of GLI, MODIS, SeaWiFS, MERIS and the AVHRRs on NOAA-16 and 17 [261]. The stable, consistent albedos provided by deep convective clouds have also been used to cross-calibrate those same AVHRR instruments and MODIS on Terra and Aqua [262].…”