Analysis of TerraSAR-X data sensitivity to bare soil moisture, roughness, composition and soil crust

• Published in: Remote sensing of environment Vol. 115; no. 8; pp. 1801 - 1810
• Main Authors: Aubert, M., Baghdadi, N., Zribi, M., Douaoui, A., Loumagne, C., Baup, F., El Hajj, M., Garrigues, S.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 15.08.2011; Elsevier
• Subjects: Animal, plant and microbial ecology; Applied geophysics; Biological and medical sciences; Crusts; Earth sciences; Earth, ocean, space; Environmental Engineering; Environmental Sciences; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects. Techniques; Incidence angle; Internal geophysics; Radar; Roughness; Sand; Slaking; Slaking crust; Soil (material); Soil composition; Soil moisture; Teledetection and vegetation maps; TerraSAR-X images; Within field plot scale; X-band; TerraSAR-X images; Within field plot scale; Soil moisture; Roughness; X-band; Soil composition; Slaking crust; risk assessment; Configuration; data; 2010; clay; Surface structure; 2009; agriculture; Loamy soil; roughness; Ground surface; Radar; water content; spatial resolution; behavior; clastic rocks; soil moisture; bare soils; incidence angle; crust; sedimentary rocks; Edaphic factor; sand; Sensitivity; signals; Environment; radar methods; TERRASAR-X IMAGES; SOIL COMPOSITION; RUGOSITE; X-BAND; HUMIDITE DU SOL; ROUGHNESS; SOIL MOISTURE; WITHIN FIELD PLOT SCALE; ANALYSE DE SENSIBILITE; PROPRIETE DU SOL; RADAR A SYNTHESE D'OUVERTURE; IMAGE SATELLITAIRE; SLAKING CRUST
• ISSN: 0034-4257; 1879-0704
• DOI: 10.1016/j.rse.2011.02.021

Soils play a key role in shaping the environment and in risk assessment. We characterized the soils of bare agricultural plots using TerraSAR-X (9.5 GHz) data acquired in 2009 and 2010. We analyzed the behavior of the TerraSAR-X signal for two configurations, HH-25° and HH-50°, with regard to several soil conditions: moisture content, surface roughness, soil composition and soil-surface structure (slaking crust). The TerraSAR-X signal was more sensitive to soil moisture at a low (25°) incidence angle than at a high incidence angle (50°). For high soil moisture (> 25%), the TerraSAR-X signal was more sensitive to soil roughness at a high incidence angle (50°) than at a low incidence angle (25°). The high spatial resolution of the TerraSAR-X data (1 m) enabled the soil composition and slaking crust to be analyzed at the within-plot scale based on the radar signal. The two loamy-soil categories that composed our training plots did not differ sufficiently in their percentages of sand and clay to be discriminated by the X-band radar signal. However, the spatial distribution of slaking crust could be detected when soil moisture variation is observed between soil crusted and soil without crust. Indeed, areas covered by slaking crust could have greater soil moisture and consequently a greater backscattering signal than soils without crust. ► Huge database for a reliable relationship between X-band signal and soil moisture. ► Effect of soil roughness on TerraSAR signal: weak and function of the soil moisture. ► The TerraSAR signal is not sensitive to slight differences in soil composition. ► Hydric state of slaking crust explain the signal variations at the within-plot scale.