Status for: Land Surface Temperature and Emissivity (MOD21)

 
General Accuracy Statement

Stage 1 Validation has been achieved for the MODIS MxD21 Collection 6 LST&E product.

The MxD21 Land Surface Temperature and Emissivity (LST&E) product has been validated to Stage 1 using a combination of Temperature- and Radiance-based methods over select sites in the Southwest USA including two water sites (Lake Tahoe, Salton Sea), six desert sand dune sites (Algodones, Kelso, Great Sands, Killpecker, Little Sahara, White Sands), and two vegetated sites (Redwood forest, Texas grassland). These Stage 1 sites, although regional in scope, are representative of major global land cover types. Matchup data covered two different time periods from 2003-2005 and 2012-2014. Stage 2 validation will be achieved once a global set of sites are investigated over a longer time period of data acquisitions.

Results for the Stage 1 validation of MxD21 LST data over Southwest USA sites showed stable and accurate LST retrievals to within 1 K RMSE with negligible bias, and were independent of land cover type. Average emissivity differences between retrieved MxD21 emissivity spectra and the lab measured spectra were within 0.01 (1%) error at all sites.

Note to users: The Collection 6 (C6) Terra Level 2 and Level 3 MODIS LST products (MOD21) for the 2000-2005 time period are being released to the public with a provisional maturity status, as these products may have been negatively impacted by an optical crosstalk issue in the infrared bands (B27-B30).  Although the crosstalk issue was present from the beginning of the mission, the impact on the product is not significant until after 2005. Thus, the Terra LST products are not being produced beyond 2005. The Aqua MODIS data are not affected by this crosstalk issue and the MYD21 LST products are considered to be science quality data with a Stage 1 validation status.

Details of MxD21 C6 LST&E validation practices can be found in the MxD21 ATBD and in Malakar et al. 2016 (listed below).

LST Val MOD21 graphic
Example of MOD21/MOD11 Radiance-based LST validation at the Algodones Dunes (left) and a Temperature-based LST
validation at the Lake Tahoe (right) validation sites. The corresponding emissivity validation between retrieved MOD21
emissivity, MOD11 classification emissivity, and lab spectra are shown below.


Product status updated:  October 2019
Product version:  Collection 6
 
Supporting Studies:

Title: A Water Vapor Scaling Model for Improved Land Surface Temperature and Emissivity Separation of MODIS Thermal Infrared Data, Remote Sensing of Environment
Author: Malakar, N.K. and G. C. Hulley
Source: Remote Sensing of Environment, Volume 182, 252-264
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Title: Thermal-based techniques for land cover change detection using a new dynamic MODIS multispectral emissivity product (MOD21)
Author: Hulley, G., S. Veraverbeke, S. Hook
Source: Rem. Sens. Environ, 140, p755-765
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Title: Quantifying Uncertainties in Land Surface Temperature (LST) and Emissivity Retrievals from ASTER and MODIS Thermal Infrared Data
Author: Hulley, G. C., T. Hughes, and S. J. Hook
Source: J. Geophys. Res. Lett, 117, D23113, doi:10.1029/2012JD018506
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Title: A radiance-based method for estimating uncertainties in the Atmospheric Infrared Sounder (AIRS) land surface temperature product
Author: Hulley, G. C., and S. J. Hook
Source: J. Geophys. Res. Lett, 117, D20117, doi:10.1029/2012JD019102
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Title: Generating Consistent Land Surface Temperature and Emissivity Products Between ASTER and MODIS Data for Earth Science Research
Author: Hulley, G. C., and S. J. Hook
Source: IEEE Trans. Geos. Rem. Sens., DOI: 10.1109/TGRS.2010.2063034
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Title: Validation of the North American ASTER Land Surface Emissivity Database (NAALSED) version 2.0 using pseudo-invariant sand dune site
Author: Hulley, G. C., S. J. Hook, and A. M. Baldridge
Source: Remote Sens. Environ, 113, 2224-2233
View Abstract and Access Publication