The optical trapezoid model: A novel approach to remote sensing of soil moisture applied to Sentinel-2 and Landsat-8 observations

REMOTE SENSING OF ENVIRONMENT

卷:198

Article

Sadeghi, Morteza¹  Babaeian, Ebrahim²  Tuller, Markus²  Jones, Scott B.¹ 

[1] Utah State Univ, Dept Plants Soils & Climate, Logan, UT 84322 USA

[2] Univ Arizona, Dept Soil Water & Environm Sci, Tucson, AZ USA

关键词: Satellite remote sensing;    Soil moisture;    Surface reflectance;    Sentinel-2;    Landsat-8;   

DOI  :  10.1016/j.rse.2017.05.041

来源: Elsevier

【 摘 要 】

The trapezoid or triangle model constitutes the most popular approach to remote sensing (RS) of surface soil moisture based on coupled thermal (Le., land surface temperature) and optical RS observations. The model, hereinafter referred to as Thermal-OptiCal TRAapezoid Model (TOTRAM), is based on interpretation of the pixel distribution within the land surface temperature - vegetation index (LST-VI) space. TOTRAM suffers from two inherent limitations. It is not applicable to satellites that do not provide thermal data (e.g., Sentinel-2) and it requires parameterization for each individual observation date. To overcome these restrictions we propose a novel Optical TRApezoid Model (OPTRAM), which is based on the linear physical relationship between soil moisture and shortwave infrared transformed reflectance (SIR) and is parameterized based on the pixel distribution within the SIR-VI space. The OPTRAM-based surface soil moisture estimates derived from Sentinel-2 and Landsat-8 observations for the Walnut Gulch and Little Washita watersheds were compared with ground truth soil moisture data. Results indicate that the prediction accuracies of OPTRAM and TOTRAM are comparable, with OPTRAM only requiring observations in the optical electromagnetic frequency domain. The volumetric moisture content estimation errors of both models were below 0.04 cm(3) cm(-3) with local calibration and about 0.04-0.05 cm(3) cm(-3) without calibration. We also demonstrate that OPTRAM only requires a single universal parameterization for a given location, which is a significant advancement that opens a new avenue for remote sensing of soil moisture. (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

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