气候变化领域集成服务门户(CCPortal): A multi-sensor approach to retrieve emissivity angular dependence over desert regions

CCPortal

DOI	10.1016/j.rse.2019.111559
	A multi-sensor approach to retrieve emissivity angular dependence over desert regions
	Ermida S.L.; Trigo I.F.; Hulley G.; DaCamara C.C.
发表日期	2020
ISSN	00344257
卷号	237
英文摘要	Land surface emissivity is a directional quantity and most natural surfaces are anisotropic emitters. Experimental studies show that for homogeneous surfaces like bare soils, the emissivity decreases with view angle. Translation of the directionality of emissivity as obtained from experiments or models to satellite spatial scales of kilometers or more is challenging given the natural heterogeneity of the land surface at those scales. We propose a multi-sensor approach to retrieve TIR emissivity angular dependence from satellite observations. The method is based on simultaneous radiance measurements over stable and homogeneous targets, performed by multiple remote sensing platforms in low-earth orbit (MODIS/VIIRS) and geostationary orbits (SEVIRI) with different viewing configurations. In the case of homogeneous scenes, we assume that differences in observed brightness temperatures are exclusively due to differences in the atmospheric optical path and in surface emissivity within each view angle, as surface temperature is the same for both sensors. We then use radiative transfer simulations to derive the emissivity changes between the sensors due to the viewing position. It is shown that emissivity values decrease with view angle for all thermal infrared channels considered, with the highest variations for channel centered at 8.7 μm, followed by 10.8 and 12.0 μm, respectively. The MODIS MYD21 product agrees with the multi-sensor approach for the 8.7 μm channel but shows negligible dependence on view angle for 10.8 and 12.0 μm bands. Results suggest that the emissivity calibration curve used in the MYD21 algorithm restricts the retrieval of the full angular variation of emissivity at these channels. A sensitivity analysis shows that the proposed multi-sensor method is robust, with reduced impact of the uncertainty of the atmospheric correction on the retrieval. The impact of emissivity angular dependence on retrieved LST may be as high as 3.0 and 1.0 K, respectively, for the GSW and the TES algorithms for angles up to 65°. © 2019 Elsevier Inc.
英文关键词	Angular effects; Anisotropy; Land surface emissivity; Multi-sensor; TES
语种	英语
scopus关键词	Anisotropy; Geostationary satellites; Orbits; Radiometers; Remote sensing; Sensitivity analysis; Surface measurement; Tellurium; Uncertainty analysis; Angular effects; Atmospheric corrections; Brightness temperatures; Land surface; Multi sensor; Radiative transfer simulations; Remote sensing platforms; Thermal infrared channels; Electromagnetic wave emission; algorithm; atmospheric correction; calibration; genetic algorithm; heterogeneity; MODIS; radiative transfer; remote sensing; sensitivity analysis; surface temperature; VIIRS
来源期刊	Remote Sensing of Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179535
作者单位	Instituto Português do Mar e da Atmosfera (IPMA), Lisbon, Portugal; Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal; NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
推荐引用方式 GB/T 7714	Ermida S.L.,Trigo I.F.,Hulley G.,et al. A multi-sensor approach to retrieve emissivity angular dependence over desert regions[J],2020,237.
APA	Ermida S.L.,Trigo I.F.,Hulley G.,&DaCamara C.C..(2020).A multi-sensor approach to retrieve emissivity angular dependence over desert regions.Remote Sensing of Environment,237.
MLA	Ermida S.L.,et al."A multi-sensor approach to retrieve emissivity angular dependence over desert regions".Remote Sensing of Environment 237(2020).