Pre-Launch Stray Light Characterization of the Landsat 9 Thermal Infrared Sensor (TIRS-2) Instrument
Abstract
The Thermal Infrared Sensor 2 (TIRS-2) payload for the Landsat 9 mission closely follows the design of the TIRS-1 instrument currently flying aboard Landsat 8. The TIRS-2 instrument, however, incorporates an important design change to mitigate the stray light issue that plagued the TIRS-1 instrument. Shortly after launch, calibration errors due to stray light artifacts were observed in Earth imagery from TIRS-1 up to magnitudes of 4% (10.8 micron band) and 8% (12.0 micron band). On-orbit out-of-field scans of the Moon were conducted to map out the angles from which out-of-field radiance was detected on the focal plane arrays. Reverse optical modeling of the lunar data identified the primary scattering sources within the TIRS-1 telescope and these results were then used to determine the locations and shapes of mitigating baffles for TIRS-2. The effect of the stray light design changes to the TIRS-2 instrument were confirmed through the initial thermal-vacuum (TVAC) characterization tests and the optical models were updated to be consistent with the measured data from the TVAC tests. Preliminary assessments of TIRS-2 indicate that the stray light effects have been drastically reduced to a total magnitude of approximately 1% or less.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A31L3081M
- Keywords:
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- 3359 Radiative processes;
- ATMOSPHERIC PROCESSESDE: 3360 Remote sensing;
- ATMOSPHERIC PROCESSESDE: 0525 Data management;
- COMPUTATIONAL GEOPHYSICSDE: 0594 Instruments and techniques;
- COMPUTATIONAL GEOPHYSICS