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 similar to 0.025% instability over its orbit, similar to 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.

Automated summary

This paper reports on the calibration updates and performance testing results of the Thermal Infrared Sensor 2 (TIRS-2) on Landsat 9. By transferring the prelaunch calibration to on-orbit and implementing additional corrections, TIRS-2 is able to generate high-quality imagery. The experimental results show that TIRS-2 has an instability of approximately 0.025%, a noise equivalent delta temperature (NEdT) of around 80mK, and an absolute radiometric uncertainty of less than 1.4% within its nominal temperature range.