Evaluation of Collection-6 MODIS Land Surface Temperature Product Using Multi-Year Ground Measurements in an Arid Area of Northwest China

Lei Lu,Tingjun Zhang,Tiejun Wang,Xiaoming Zhou

doi:10.3390/rs10111852

Lei Lu, Tingjun Zhang + Show 2 more

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https://doi.org/10.3390/rs10111852

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Abstract

Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) products are widely used in ecology, hydrology, vegetation monitoring, and global circulation models. Compared to the collection-5 (C5) LST products, the newly released collection-6 (C6) LST products have been refined over bare soil pixels. This study aims to evaluate the C6 MODIS 1-km LST product using multi-year in situ data covering barren surfaces. Evaluation using all in situ data shows that the MODIS C6 LSTs are underestimated with a root-mean-square error (RMSE) of 2.59 K for the site in the Gobi area, 3.05 K for the site in the sand desert area, and 2.86 K for the site in the desert steppe area at daytime. For nighttime LSTs, the RMSEs are 2.01 K, 2.88 K, and 1.80 K for the three sites, respectively. Both biases and RMSEs also show strong seasonal signals. Compared to the error of C5 1-km LSTs, the RMSE of C6 1-km LST product is smaller, especially for daytime LSTs, with a value of 2.24 K compared to 3.51 K. The large errors in the sand desert region are presumably due to the lack of global representativeness of the magnitude of emissivity adjustment and misclassification for the barren surface causing error in emissivities. It indicates that the accuracy of the MODIS C6 LST product might be further improved through emissivity adjustment with globally representative magnitude and accurate land cover classification. From this study, the MODIS C6 1-km LST product is recommended for applications.

Highlights

Land surface temperature (LST) is a key parameter in the physics of land surface processes on regional and global scales [1]
For nighttime Terra Moderate Resolution Imaging Spectroradiometer (MODIS) LST, it is underestimated for all sites, and the root-mean-square error (RMSE) are smaller than those of the daytime LST, except for the SSW site with a large RMSE of 3.12 K
For LST from Aqua MODIS, the daytime values are underestimated for all sites, and the RMSEs are greater than those of the Terra MODIS LST (RMSEs of 2.91 K, 3.20 K, and 3.20 K for Aqua MODIS LST versus RMSEs of 2.26 K, 2.89 K, and 2.53 K for Terra MODIS LST at the GB, SSW, and HZZ sites, respectively)

Summary

Introduction

Land surface temperature (LST) is a key parameter in the physics of land surface processes on regional and global scales [1]. MOD11A1 (MYD11A1) and MOD11B1 (MYD11B1) are two standard daily LST products derived from the observations of the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra and Aqua satellites. These two LST products are retrieved separately by a generalized split-window (GSW) algorithm [8] and the day/night algorithm [9], which are available in their current collection of 4, 5, and 6 (or Version 4, 5, 6) starting from 2000 (for products from Terra observations) and 2002 (for products from Aqua observations), respectively. Validation of these products is important, and validation activities have been supported by the NASA’s Earth Observing System (EOS) project [12,13,14]

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