Title
High-Precision Soil Moisture Mapping Based on Multi-Model Coupling and Background Knowledge, Over Vegetated Areas Using Chinese GF-3 and GF-1 Satellite Data.
Abstract
This paper proposes a combined approach comprising a set of methods for the high-precision mapping of soil moisture in a study area located in Jiangsu Province of China, based on the Chinese C-band synthetic aperture radar data of GF-3 and high spatial-resolution optical data of GF-1, in situ experimental datasets and background knowledge. The study was conducted in three stages: First, in the process of eliminating the effect of vegetation canopy, an empirical vegetation water content model and a water cloud model with localized parameters were developed to obtain the bare soil backscattering coefficient. Second, four commonly used models (advanced integral equation model (AIEM), look-up table (LUT) method, Oh model, and the Dubois model) were coupled to acquire nine soil moisture retrieval maps and algorithms. Finally, a simple and effective optimal solution method was proposed to select and combine the nine algorithms based on classification strategies devised using three types of background knowledge. A comprehensive evaluation was carried out on each soil moisture map in terms of the root-mean-square-error (RMSE), Pearson correlation coefficient (PCC), mean absolute error (MAE), and mean bias (bias). The results show that for the nine individual algorithms, the estimated model constructed using the AIEM (m(v1)) was significantly more accurate than those constructed using the other models (RMSE = 0.0321 cm(3)/cm(3), MAE = 0.0260 cm(3)/cm(3), and PCC = 0.9115), followed by the Oh model (m_v5) and LUT inversion method under HH polarization (m(v2)). Compared with the independent algorithms, the optimal solution methods have significant advantages; the soil moisture map obtained using the classification strategy based on the percentage content of clay was the most satisfactory (RMSE = 0.0271 cm(3)/cm(3), MAE = 0.0225 cm(3)/cm(3), and PCC = 0.9364). This combined method could not only effectively integrate the optical and radar satellite data but also couple a variety of commonly used inversion models, and at the same time, background knowledge was introduced into the optimal solution method. Thus, we provide a new method for the high-precision mapping of soil moisture in areas with a complex underlying surface.
Year
DOI
Venue
2020
10.3390/rs12132123
REMOTE SENSING
Keywords
DocType
Volume
soil moisture,multi-model coupling,optimal solution method
Journal
12
Issue
Citations 
PageRank 
13
0
0.34
References 
Authors
0
5
Name
Order
Citations
PageRank
Leran Han100.68
Chunmei Wang200.68
Tao Yu363.56
Xingfa Gu45436.00
Qiyue Liu552.53