Land Surface Temperature from Landsat 5 TM images: comparison of different methods using airborne thermal data
In this study, several methods to compute land surface temperatures (LST) from Landsat TM5 data are compared. Two different approaches are considered. An image based approach that takes into account atmospherically corrected data by using a dark object subtraction model (DOS-1) and computes the em...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Eastern Macedonia and Thrace Institute of Technology
2015-10-01
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| Series: | Journal of Engineering Science and Technology Review |
| Subjects: | |
| Online Access: | http://www.jestr.org/downloads/Volume8Issue3/fulltext83122015.pdf |
| Summary: | In this study, several methods to compute land surface temperatures (LST) from Landsat TM5 data are compared. Two
different approaches are considered. An image based approach that takes into account atmospherically corrected data by
using a dark object subtraction model (DOS-1) and computes the emissivity as NDVI function. The emissivity of a
surface is controlled by such factors as water content, chemical composition, structure and roughness; it can be
determined as the contribution of the different components that belong to the pixels according to their proportions. NDVI
method takes into account that vegetation and soils are the main surface cover for the terrestrial component. This
emissivity is used to compute the LST by the inversion of Planck function. The other approach applies atmospheric
correction to thermal infrared band and considers a constant emissivity of 0.95. Furthermore, the land surface temperature
is computed by hybrid methods that result from the merger of the two initially considered approaches. These results are
compared with the surface temperature measured by airborne Multispectral Infrared and Visible Imaging Spectrometer
(MIVIS). The LST measured by MIVIS sensor can be considered closer to the real surface temperature because the data
are acquired at an altitude of 1500 m and are not affected by significant atmospheric effects such as for satellite data,
acquired at 705 km from the Earth’s surface. The best results are obtained by considering variable emissivity. |
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| ISSN: | 1791-2377 1791-2377 |