Potential of X-Band TerraSAR-X and COSMO-SkyMed SAR Data for the Assessment of Physical Soil Parameters

Remote Sensing

Azza Gorrab³  Mehrez Zribi³  Nicolas Baghdadi²  Bernard Mougenot³  Zohra Lili Chabaane¹  Yoshio Inoue⁴ 

[1] University of Carthage/INAT, 43 av. Charles Nicolle 1082, Tunis, Mahrajène Tunisie, Tunisia; E-Mail:;IRSTEA, UMR TETIS, 500 rue François Breton, 34093 Montpellier Cedex 5, France; E-Mail:;CESBIO (CNRS/UPS/IRD/CNES), 18 av. Edouard Belin, 31401 Toulouse Cedex 9, France; E-Mails:CESBIO (CNRS/UPS/IRD/CNES), 18 av. Edouard Belin, 31401 Toulouse Cedex 9, France;

关键词: soil moisture;    soil roughness;    TerraSAR-X;    COSMO-SkyMed;    SAR;    IEM;    Baghdadi-calibrated IEM model;    Dubois model;   

DOI  :  10.3390/rs70100747

来源: mdpi

【 摘 要 】

The aim of this paper is to analyze the potential of X-band SAR measurements (COSMO-SkyMed and TerraSAR-X) made over bare soils for the estimation of soil moisture and surface geometry parameters at a semi-arid site in Tunisia (North Africa). Radar signals acquired with different configurations (HH and VV polarizations, incidence angles of 26° and 36°) are statistically compared with ground measurements (soil moisture and roughness parameters). The radar measurements are found to be highly sensitive to the various soil parameters of interest. A linear relationship is determined for the radar signals as a function of volumetric soil moisture, and a logarithmic correlation is observed between the radar signals and three surface roughness parameters: the root mean square height (Hrms), the parameter Zs = Hrms²/l (where l is the correlation length) and the parameter Zg = Hrms × (Hrms/l)^α (where α is the power of the surface height correlation function). The highest dynamic sensitivity is observed for Zg at high incidence angles. Finally, the performance of different physical and semi-empirical backscattering models (IEM, Baghdadi-calibrated IEM and Dubois models) is compared with SAR measurements. The results provide an indication of the limits of validity of the IEM and Dubois models, for various radar configurations and roughness conditions. Considerable improvements in the IEM model performance are observed using the Baghdadi-calibrated version of this model.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.