NOAA-21 ATMS Geolocation Performance Post-Launch Validation

For ATMS, the dominant contributions to static geolocation error are the antenna beam misalignment and the instrument mounting error. Even though these static error terms are measured in the prelaunch ground test and the corrections have been included in the geolocation process, residual errors may still exist due to the on-orbit thermal dynamic change and shift during the launch. Therefore, post-launch assessment and monitoring of static errors are necessary for improving the on-orbit geolocation accuracy. The Coastline Inflection Point (CIP) method as described by Zhou and Yang (doi: 10.1109/TGRS.2018.2887407) is used to perform post-launch assessment and monitoring of geolocation errors.

On 10 November 2022, the JPSS-2 satellite was launched and became NOAA-21 five days later on 16 November. On 21 November, NOAA-21 ATMS TDR and SDR products began to flow. For about 6 months after this, the NOAA-21 ATMS geolocation was assessed during the post-launch test (PLT) period. This presentation discusses general post-launch analysis of NOAA-21 ATMS geolocation performance, including pre and post Processing Coefficient Table (PCT) update analysis, and pre and post Permanent Pitch Adjustment (PPA) analysis. It also compares the performance of NOAA-21 ATMS geolocation relative to that of NOAA-20 and S-NPP ATMS units.