SOIL MOISTURE CHARACTERIZATION USING MULTI-ANGULAR POLARIMETRIC RADARSAT-2 DATASETS

International audienceThe use of multi-angular polarimetric datasets instead of the standard single-angular data is considered to be a solution to improve the effectiveness of bare soil char- acterization. However, the potential of polarimetric pa- rameters derived from the multi-angular SAR datasets was studied little, particularly for the C band polarimet- ric datasets. In this study, the sensitivity of polarimetric descriptors from single and multiple incidence angle acquisitions is investigated against in situ soil moisture and surface roughness. The behaviours of polarimetric descriptors are compared with the simulations using integral equation model (IEM). The results show that the variation of polarimetric descriptors in term of soil moisture as well as surface roughness is in accordance with the IEM simulations; even though the variation scale is different between the real data and simulation (The simulation is more sensitive than the real data). The polarimetric sensitivity found in this study provides additional evidences for the potential utilization of multi-angular polarimetric SAR datasets for bare sur- face characterization

Sensitivity of Main Polarimetric Parameters of Multifrequency Polarimetric SAR Data to Soil Moisture and Surface Roughness Over Bare Agricultural Soils

International audienceThe potential of polarimetric synthetic aperture radar data for the soil surface characterization of bare agricultural soils was investigated by using air- and spaceborne data acquired by Radar Aéroporté Multi-Spectral d'Etude des Signatures (RAMSES), Système Expérimental de Télédétection Hyperfréquence Imageur (SETHI), and RADARSAT-2 sensors over several study sites in France. Fully polarimetric data at ultrahigh frequency, X-, C-, L-, and P-bands were compared. The results show that the main polarimetric parameters studied (entropy, α angle, and anisotropy) are not very sensitive to the variation of the soil surface parameters. Low correlations are observed between the polarimetric and soil parameters (moisture content and surface roughness). Thus, the polarimetric parameters are not very relevant to the characterization of the soil surface over bare agricultural areas

A potential use for the C-band polarimetric SAR parameters to characterise the soil surface over bare agriculture fields

The objective of this study was to analyze the potential of the C-band polarimetric SAR parameters for the soil surface characterization of bare agricultural soils. RADARSAT-2 data and simulations using the Integral Equation Model (IEM) were analyzed to evaluate the polarimetric SAR parameters' sensitivities to the soil moisture and surface roughness. The results showed that the polarimetric parameters in the C-band were not very relevant to the characterization of the soil surface over bare agricultural areas. Low dynamics were often observed between the polarimetric parameters and both the soil moisture content and the soil surface roughness. These low dynamics do not allow for the accurate estimation of the soil parameters, but they could augment the standard inversion approaches to improve the estimation of these soil parameters. The polarimetric parameter alpha_1 could be used to detect very moist soils (>30%), while the anisotropy could be used to separate the smooth soils

Two novel surface model based inversion algorithms using multi-frequency polSAR data

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