STAR Joint Polar Satellite System Algorithms & Data Products website National Oceanographic & Atmospheric Administration website NOAA Center for Satellite Applications and Research website

Cross-Track Infrared Sounder (CrIS)

Team Lead: Flavio Iturbide


The Cross-track Infrared Sounder (CrIS) is the first in a series of advanced operational sounders that will provide more accurate, detailed atmospheric temperature and moisture observations for weather and climate applications. This information will help significantly improve climate prediction and both short-term weather "nowcasting" and longer-term forecasting.

Measures upwelling infrared radiance at very high spectral resolution

  • 1,305 spectral channels (SWIR: 3.92-4.64µm; MWIR: 5.71-8.26µm; LWIR: 9.14-15.38µm) at nominal mode (NSR), with resolution at 0.625, 1.25, and 2.5 cm-1 for the LWIR, MWIR, SWIR bands, respectively
  • 2211 spectral channels at full spectral resolution (FSR) mode, with resolution at 0.625 cm-1 for all three bands.
  • Low noise levels (NEdN)
  • Much finer resolution for improved vertical soundings increasing both radiometric and spectral accuracy
  • Data is combined with ATMS to produce vertical profiles of the temperature, moisture, and pressure
  • Typical temperature retrieval accuracy well below 1K

Cross-track Infrared Sounder (CrIS) is a key sensor

  • Fourier Transform Spectrometer providing high resolution IR spectra:
    • Fields of Regard each 3 x 3 FOVs
    • Photovoltaic Detectors in all 3 bands
    • 4-Stage Passive Detector Cooler
    • On-board internal calibration target

Science heritage:

  • AIRS on EOS Aqua, IASI on METOP-A/B

CrIS truncated data products (NSR)

The normal spectral resolution (NSR, or truncated data) CrIS SDR data products for both S-NPP and NOAA-20 are Terminated on 11/02/2020 1540Z.

Cross-Track Infrared Sounder instrument from JPSS satellite

CrIS NSR unapodized channel response function

CrIS unapodized channel response function

CrIS NSR apodized channel response function

CrIS apodized channel response function


CrIS Specifications

Instrument Frequency Band Spectral Range (cm-1) Spectral Range (µm) Number of In-band Channel (Unapodized Channel) Spectral Resolution (cm-1) Effective Maximum Path Difference (MPD) (cm) Number of channels with Guard Bands Decimation Factor
CrIS NSR Longwave 650-1095 15.38-9.14 713* (717) 0.625 0.8 864 24
Mid-wave 1210-1750 8.26-5.71 433* (437) 1.25 0.4 528 20
Shortwave 2155-2550 4.64-3.92 159* (163) 2.5 0.2 200 26
CrIS FSR Longwave 650-1095 15.38-9.14 713* (717) 0.625 0.8 864 24
Mid-wave 1210-1750 8.26-5.71 865* (869) 0.625 0.8 1050 20
Shortwave 2155-2550 4.64-3.92 633* (637) 0.625 0.8 797 26

*: Apodized channel