Performance of JPSS-1 and Suomi NPP ATMS Instruments

Suomi NPP Advanced Technology Microwave Sounder (ATMS) has been operational since 2012. JPSS-1 will be launched soon. In the space we will have both Suomi NPP and J1 ATMS measurements within a time frame of about 15 minutes. 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. Because of the relatively short time difference between Suomi NPP and JPSS-1 orbits, it will provide great opportunities to investigate scan-dependent bias asymmetry using a nadir observation from one satellite and an off-nadir observation from the other satellite. The collocated data will also be valuable to study and develop the limb-correction algorithm for the ATMS imagery.

We have analyzed the ATMS sensor response function (SRF) measurements and will present the impact of the SRF on the simulation of the ATMS brightness temperature. In the past, a box-cut approximated SRF is used in radiative transfer calculations since the SRF was often not measured or evaluated.

In this presentation, we will also present the JPSS-1 ATMS performance such as noise, bias, channel noise correction based on thermal vacuum TVAC measurements. The 3 parameters are critical to radiometric accuracy and they are the most important to users. Using the thermal vacuum TVAC measurements, we are also able to derive the channel noise correlation that plays a role in the satellite data assimilation and satellite product generation.