Spatial resolution enhancement of the land surface thermal field imagery based on multiple regression models on multispectral data from various space systems

1Zyelyk, Ya.I, 1Chornyy, SV, 1Fedorov, OP, 1Pidgorodetska, LV, 1Kolos, LM
1Space Research Institute of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Kyiv, Ukraine
Space Sci. & Technol. 2023, 29 ;(1):03-14
https://doi.org/10.15407/knit2023.01.003
Publication Language: English
Abstract: 
The methodology has been developed for enhancement the spatial resolution of the land surface thermal field satellite imagery based on the following steps: coupling images in the visible, thermal and radar ranges into the single multispectral data product; constructing of regression models of the images relationship; performing the linear regression of the pseudo-thermal product with enhanced spatial resolution on the visible and radar ranges data. The methodology is implemented on the Google Earth Engine open cloud platform using the Earth Engine API and the software scripts created in the JavaScript language with the processing of multispectral image collections of various space systems at specified time intervals.
       The possibility of practical synthesis of the pseudo-thermal image with enhanced spatial resolution of 10 m based on the thermal image with the resolution of 100 m and the multispectral composite with the layers resolution of 10 m and 30 m is shown.
       The technology has been developed for synthesis and calibration of the land surface temperature product with enhanced spatial resolution and data providing rate everyday based on the brightness temperature product in the B10 band of Landsat 8 and linear regression on the MODIS, ASTER and Sentinel-1 products with data providing rate from everyday to moderate. The software in JavaScript has been developed and technology in the interactive web service form with open access on the Google Earth Engine Apps cloud platform has been implemented.
The final data product provides the satisfactory relative root mean square error of the brightness temperature recovery of not more than 6% according to the reference cross-calibration data of the B10 Landsat 8 band in the moderate thermal field (up to 100° C). The relative root mean square errors of the synthesized data according to the reference data on high-temperature sites (fire, hot lava) up to 28% are due to fact that the synthesized product contains information from high-temperature spectral bands (B07-B09 from ASTER), while the reference product (B10 from Landsat 8) does not contain such information.
       Technology implementation examples show that cross-calibration of the synthesized product can be performed during the year from March to October according to reference thermal images of natural or artificial objects. Objects selected for calibration must have stable thermal characteristics at the time of satellites flight during the data acquisition period.
Keywords: brightness temperature, data providing rate, Google Earth Engine, heterogeneous multispectral data coupling, land surface temperature, multiply linear regression, product cross-calibration, space resolution of imagery
References: 
1. Zyelyk Ya.I., Podgorodetskaya L.V., Chornyy S.V. (2019) Estimation of the thermodynamic temperature of the earth's surface using satellite data based on the land cover classification in the optical radiation range. Journal of Automation and Information Sciences. Begell House, V. 51, I. 6, 25-40.
2. Stankevich S.A., Filipovich V.E., Lubsky М.S., Krylova A.B., Kritsuk S.G., Brovkina O.V., Gornyy V.I., Tronin A.A. (2015) Intercalibration of methods for the land surface thermodynamic temperature retrieving inside urban area by thermal infrared satellite imaging. Ukrainian Journal of Remote Sensing, 7, 12-21.
URL: http://ujrs.org.ua/ujrs/article/view/59/77 (Last accessed: 2022.06.01) [In Russian].
3. Zyelyk Ya.I., Pidgorodetska L.V., Chornyy S.V. (2018) Estimation of the thermodynamic temperature field of the land surface using satellite data based on land cover classification. Astronomical School's Report, 14 (2), 70-77.
4. Zyelyk Yа., Chornyy S., Pidgorodetska L. (2017) Mathematical models of the joint calibration process and optimal filtration of integrated multispectral data products of space earth observations in visible, thermal and radio spectral bands. Abstracts of the 17th Ukrainian Conference on Space Research, Odesa, August, 21-25, P. 195.
5. Google Earth Engine. Linear Regression. URL: https://developers.google.com/earth-engine/guides/reducers_regression (Last accessed: 2022.06.01). 6. Google Earth Engine Apps. Thermal Images Processing to get 10 m Spatial Resolution by S1, L8 Data Regression. Developed by S. Chornyy, JS Code 1.