soil moisture profile effect on radar signal measurement对雷达信号测量土壤水分剖面的影响.pdf

Sensors 2008, 8, 256-270 sensors ISSN 1424-8220 © 2008 by MDPI /sensors Full Research Paper Soil Moisture Profile Effect on Radar Signal Measurement Aurélie Le Morvan 1, Mehrez Zribi 1,*, Nicolas Baghdadi 2 and André Chanzy 3 1 CETP/CNRS, 10-12 av. de lEurope, 78140 Vélizy, France; E-mail: Aurelie.LeMorvan@cetp.ipsl.fr 2 Bureau de Recherches Géologiques et Minières (BRGM), 3- av. C. Guillemin, B.P. 6009, 45060 Orléans cedex 2, France 3 INRA-Avignon, Centre de Recherches dAvignon Domaine Saint Paul , Site Agroparc 84914 Avignon cedex 9, France * Author to whom correspondence should be addressed. Tel.: +33 1 39 25 48 23; Fax: +33 1 39 25 49 22; E-mail: zribi@cetp.ipsl.fr Received: 22 November 2007 / Accepted: 8 January 2008 / Published: 21 January 2008 Abstract: The objective of this paper is to analyze the behaviour of a backscattered signal according to soil moisture depth over bare soils. Analysis based on experimental vertical moisture profiles and ASAR/ENVISAT measurements has been carried out. A modified IEM model with three permittivity layers (0-1cm, 1-2cm, 2-5cm) has been developed and used in this study. Results show a small effect of moisture profile on the backscattered signal (less than 0.5dB). However, measurements and simulations have provided a more detailed insight into the behaviour of the radar signal and have shown that it was important to consistently use the same protocol when performing ground truth measurements of soil moisture. Keywords