The Living Planet Program : Soil Moisture and Ocean Salinity (SMOS)

have a look at the SMOS Blog:
the news of the CESBIO SMOS team



For any questions or
comments on this mission, please contact :
Yann Kerr at CESBIO

© Copyright 2009 CESBIO, 
Tous droits réservés



SMOSREX (Surface Monitoring Of Soil Reservoir Experiment) is conducted in the framework of preparation for the SMOS mission (Soil Moisture and Ocean Salinity).

SMOSREX use simultaneously:

  • (1) L band ( LEWIS instrument),
  • (2) multi-frequencies measurements ( L, IRT, PIR, VIS),
  • (3) soil measurements (meteorology, soil, vegetation) and soil moisture at different depths.

(4) modelling of surface processes and radiative transfer. SMOSREX (2003-2010) will consider a wide range of weather, hydrology, phenology variables and their interactions.

The experimental site is located on the ONERA site (43°23'N, 1°17'E, altitude 188m), 30km south of Toulouse. SMOSREX is conducted with the CNRM, ONERA and INRA-Bordeaux. It is a part of the PIRRENE program : Programme Interdisciplinaire de Recherche sur la Radiométrie en Environnement Extérieur


Conducted jointly with the airborne campaign COSMOS, SMOSREX can consider both theoretical issues related to remote sensing of soil moisture and its applications to modelling. For this this field campaign, there is several objectives :

  • (1) on one hand to develop and improve direct and inverse algorithms with L-band
  • (2) secondly to study the contribution of remote sensing of soil moisture for understanding and modelling soil-plant-atmosphere processes

L band Radiometer for Estimating Water In Soils " (LEWIS)

In the framework of the SMOS mission, an experimental site was developed and installed. The main objective is to test and evaluate the algorithms used to estimate the surface moisture. The site has been equipped with the "L band Radiometer for Estimating Water In Soils instrument" (LEWIS)

With measurements (brightness temperatures, weather) we will :

  • study the soil moisture during weather events such as frost, dew ....
  • influence of the vegetation on the measured signal in L band
  • to estimate soil moisture in root zone.

For this purpose, a site near Toulouse was equipped with two types of surfaces (Bare soil and grass).


A structure has been built with a pointing system and data acquisition to carry the L-band radiometer After a testing period, the system is now operational.

LEWIS"L band Radiometer :

  • High Quality Ground based radiometer1.4 GHz,
  • H & V sensitivity 0.1 K,
  • Stability < 0.05K,
  • main lobe 12.5 @3db, 22° beam efficiency 0.986,
  • No « visible » back lobes
Operational since 23/1/2003
  • Design and Test of the Ground-Based L band Radiometer for Estimatingring Water In Soils ( LEWIS) 
  • Exemple de cycle diurne de la température de brillance acquis par l'instrument LEWIS en polarisation H/V sur un sol nu et sur un couvert herbacé. image

Scientific works around SMOSREX

  • Escorihuela, MJ, Chanzy A.,, Wigneron J.-P. and Kerr, YH (2010) Effective soil moisture sampling depth of L-band radiometry: A case study, Remote Sensing of Environment, vol 114, pp995-1001.
  • Etude des effets de la rugosité sur l'émission en bande-L du sol nu
    MIALON Arnaud, WIGNERON Jean-Pierre, DEROSNAY Patricia, Escorihuela M.-J.KERR Yann
    Présentation poster à la conférence : MICRORAD 2008, Florencia, Italy abstract   poster
  • Escorihuela, MJ and Kerr, YH and de Rosnay, P. and Wigneron, J.P. and Calvet, J.C. and Lemaitre, F., 2007. A Simple Model of the Bare Soil Microwave Emission at L-Band, Geosc. Remote Sens., vol.45 (n7 Part 1),p 1978-1987.image
  • de Rosnay P., Calvet J.-C., Kerr Y., Wigneron J.-P., Lematre F., Escorihuela M.J., Muoz-Sabater J., Saleh K., Barri J., Bouhours G., Coret L., Cherel G., Dedieu G., Durbe R., Fritz N.E.D., Froissard F., Hoedjes J., Kruszewski A., Lavenu F., Suquia D., Waldteufel P. : "SMOSREX: A Long Term Field Campaign Experiment for Soil Moisture and Land Surface Processes Remote Sensing" Remote Sensing of Environment, 102, 377-389, 2006 doi:10.1016/j.rse.2006.02.021 image
  • Rapport du workshop EGU du 27 avril 2005 a Vienne :

1 - introduction image
2 - A Brief Overview of Passive Microwave Experiments over Land - image
3 - SMOSREX: A Long Term Field Campaign Experiment for Soil Moisture and Land Surface Processes Remote Sensing. image
4 - L-Band Radiometry Experiments with ELBARA image
5 - NAFE - National Airborne Field Experiment image
6 - Assimilation: field and airborne campaigns SMOSMANIA image

  • SMOS Rex Case Study : Determination of the effective Temperature for L-band  Radiometry,  (EGU-2004)
     P. de Rosnay, T. Holmes., J.P. Wigneron Y. Kerr, J.C. Calvet, M.J. Escorihuela, K. Saleh,   F. Lemaître image
  • SMOSREX : Surface Monitoring Of the Soil Reservoir EXperiment  Experiment design and results (EGU-2004)  M.J. Escorihuela, P. de Rosnay, Y. Kerr, J.C. Calvet, F. Lemaitre,  J.P. Wigneron, J.P. Waldteufel, N.E.D. Fritz image
  • Télédétection de l'humidité des sols. Présentation de l'expérience SMOSREX
     P. de Rosnay, Y. Kerr, J.C. Calvet, F. Lemaître, M.J. Escorihuela, J.P. Wigneron image
  • Expérience SMOSREX  Télédétection de l'humidité des sols
     P. de Rosnay, Y. Kerr, J.C. Calvet, F. Lemaître, R. Duirbe, J.P. Wigneron, M.J. Escorihuela,  N.E.D. Fritz, F. Lavenu, T. Holmes image
  • Préparation de la mission SMOS Extraction de l'Humidité du soll à partir des données LEWIS- Maria José Escorihuela (juin 2003) DEA MICROONDES ET TRANSMISSION OPTIQUE image



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