Landsat 9 Thermal Infrared Sensor 2 On-Orbit Calibration and Initial Performance.

The Thermal Infrared Sensor 2 (TIRS-2) on Landsat 9 (L9) was launched on September 27, 2021, and underwent a variety of tests during its commissioning phase to establish its postlaunch performance. We report on the calibration updates performed to maintain its calibration and generate high-quality imagery. This is done by transferring the SI-traceable prelaunch calibration to on-orbit while accounting for changes in the TIRS-2 response as detected through on-board calibrator observations. Additional empirical corrections were implemented to mitigate image striping observed on-orbit. The detector arrays were monitored through its commissioning phase to ensure that stable detectors were chosen for operations. TIRS-2 has demonstrated ~0.025% instability over its orbit, ~80-mK noise equivalent delta temperature (NEdT), and an absolute radiometric uncertainty <1.4% in its nominal temperature range enabling a wide array of Earth science applications. [ABSTRACT FROM AUTHOR]