Correction of thin cirrus absorption effects in Landsat 8 TIRS Images using the OLI cirrus band on the same satellite platform

Authors: GAO, B - Naval Research Laboratory; LI, R - Naval Research Laboratory; YANG, YUN - Mississippi State University; Anderson, Martha

Submitted to: Sensors
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2024
Publication Date: 7/19/2024
Citation: Gao, B., Li, R., Yang, Y., Anderson, M.C. 2024. Correction of thin cirrus absorption effects in Landsat 8 TIRS Images using the OLI cirrus band on the same satellite platform. Sensors. 24/4697. https://doi.org/10.3390/s24144697.
DOI: https://doi.org/10.3390/s24144697

Interpretive Summary: Remotely sensed imagery in the thermal infrared bands provides valuable geospatial information about variations in land-surface temperature related to vegetation stress and water consumption rates, among other things. As such, remotely sensed surface temperature data are used in models used for drought monitoring, yield estimation, and water resource management. Landsat thermal data, at 100 m spatial resolution, are particularly valuable for applications – approaching the scale at which land and water are actively managed. However, thermal imagery is subject to cloud contamination, leaving features that must be masked out for the images to be useful. Most difficult to detect and mask are the thin cirrus clouds that form in the troposphere. This paper describes a simple method for removing cirrus features in thermal images, using information from a band that is sensitive to cirrus backscatter. The efficacy of the method is demonstrated using several cirrus-impacted Landsat thermal images. This method may be a beneficial complement to atmospheric correction methods currently used to create Landsat land-surface temperature products.

Technical Abstract: Data from the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS) instruments on board the Landsat 8 and Landsat 9 satellite platforms are subject to contamination by cloud cover, with cirrus contributions being the most difficult to detect and mask. To help address this issue, a cirrus detecting channel (Band 9) centered within the 1.375-˜m water vapor absorption region was implemented on OLI, with spatial resolution of 30 m. However, this band has not yet been fully utilized in the Collection 2 Landsat 8/9 Level 2 surface temperature data products that are publicly released by U.S. Geological Survey (USGS). The temperature products are generated with a single channel algorithm developed by Rochester Institute of Technology (RIT) and NASA Jet Propulsion Laboratory (JPL). The TIRS instrument has two IR bands centered near 11 and 12 ˜m, respectively. Temperature retrievals are made from the Level 1 top of atmosphere (TOA) products, such as the 11-˜m band brightness temperature (BT), the TOA reflectances, in addition to ancillary data that include Normalized Difference Vegetation Index (NDVI), surface emissivity, atmospheric profiles obtained from other sources. During the surface temperature retrievals, the effects of absorption of infrared radiation originating from the warmer earth’s surfaces by ice clouds, typically located in the upper portion of the troposphere and re-emitting at much lower temperatures (~220 K), are not taken into consideration. Through analysis of sample Level 1 TOA and Level 2 surface data products, we have found that thin cirrus cloud features present in the Level 1 1.375-˜m band images are directly propagated down to the Level 2 surface data products. The surface temperature errors resulting from thin cirrus contamination can be 10 K or larger. Previously, we reported an empirical and effective technique for removing thin cirrus scattering effects in OLI images, making use of the correlations between the 1.375-˜m band image and images of any other OLI bands located in the 0.4 – 2.5 ˜m solar spectral region. In this article, we describe a variation of this technique that can be applied to the thermal bands, using the correlations between the Level 1 1.375-˜m band image and the 11-˜m BT image for the effective removal of thin cirrus absorption effects. We expect that, if the cirrus-removed TOA 11-˜m band BT images are used for the retrieval of the Level 2 surface temperature (ST) data products, the errors resulting from thin cirrus contaminations in the ST products can be reduced to about 1 K for spatially diffused cirrus scenes.