Suomi NPP/JPSS Cross-track Infrared Sounder (CrIS): Calibration Validation With The Aircraft Based Scanning High-resolution Interferometer Sounder (S-HIS)

The Cross-track Infrared Sounder (CrIS) on Suomi NPP, launched 28 October 2011, is designed to give scientists more refined information about Earth's atmosphere and improve weather forecasts and our understanding of climate. CrIS is an infrared Fourier transform spectrometer with 1305 spectral channels, and produces high-resolution, three-dimensional temperature, pressure, and moisture profiles. These profiles will be used to enhance weather forecasting models and they will facilitate improvements to both short and long-term weather forecasting.

For improved weather prediction and climate change monitoring, there is an established need for higher accuracy and more refined error characterization of radiance measurements from space and the corresponding geophysical products. This need has led to the use of direct tests of in-orbit performance, referred to as validation. Currently, validation typically involves (1) collecting high quality temporally and spatially co-located reference data from accurately calibrated airborne or ground-based instruments with traceability to absolute standards during the satellite overpass, and (2) a detailed comparison between the satellite-based radiance measurements and the corresponding high quality reference data. Additionally for future missions, technology advancements at University of Wisconsin Space Science and Engineering Center (UW-SSEC) have led to the development of an on-orbit absolute radiance reference utilizing miniature phase change cells to provide direct on-orbit traceability to International Standards (SI).

The first Suomi NPP dedicated airborne calibration validation campaign was conducted May 2013 with a primary objective of providing detailed validation of CrIS radiance observations and meteorological products. During this calibration validation campaign, the NASA ER-2 aircraft instrument payload included the UW-SSEC Scanning-High resolution Interferometer Sounder (S-HIS), the NPOESS Atmospheric Sounder Testbed-Interferometer (NAST-I), the NPOESS Atmospheric Sounder Testbed-Microwave Spectrometer (NAST-M), the NASA MODIS/ASTER airborne simulator (MASTER), and the NASA JPL Airborne Visible / Infrared Imaging Spectrometer (AVIRIS). Eleven ER-2 under-flights of the Suomi NPP satellite were conducted during the campaign.

This presentation will include (1) an overview of the radiance calibration approach and accuracy of the S-HIS validation data, (2) a detailed assessment of a single under-flight, and (3) a summary assessment of the CrIS spectral radiance observations for the underflights.