Calibration of JPSS-1 and Suomi NPP Advanced Technology Microwave Sounders

Suomi NPP Advanced Technology Microwave Sounder (ATMS) has been operational since 2012. NOAA-20 ATMS has also been operational and both ATMSs have been achieved the validated maturity. ATMS is currently the best microwave sounder and will be one of the best microwave sounders in the future, to be launched on schedule in the fiscal year of 2022 for J2, 2026 for J3, and 2031 for J4. The future ATMS will be enhanced by the beneficial of new materials and new technology.

The ATMS is a cross-track scanner with 22 channels and provides sounding observations for atmospheric temperature, moisture, and clouds, as well as surface temperature, snow and ice. All channels are sampled every 1.1º at 96 scan positions, with a cross track swath width of about 2600 km, significantly wider than AMSU-A or MHS. ATMS channels 1 and 2 have a large beam width (low spatial resolution) of 5.5 degrees; channels 3 to 16 have a medium beam width of 2.2 degrees; and channels 17 to 22 have a small beam width of 1.1 degrees.

In this presentation, we will present the NOAA-20 ATMS performance such as noise, bias, channel noise correction, striping, and others. We will compare the ATMS performance between the NOAA-20 and Suomi NPP. The ATMS have been demonstrated great values. As examples, we will also show few of the ATMS products or environmental data records. Using the ATMS data, NOAA Microwave Integrated Retrieval System (MiRS) operationally generates atmospheric profiles of temperature and water vapor, cloud liquid water, ice water content, rainfall rate, snow cover and snow water equivalent, snow fall rate, surface temperature and microwave emissivity, and sea ice concentration. The MiRS is based on 1D-VAR retrieval algorithm which includes the Community Radiative Transfer Model (CRTM) for computing radiances and the gradient of radiance (or Jacobian), and a scheme for minimizing the cost function that weighs the relative contribution of background (a priori) information and satellite observations.