Diurnal variations of the radiometric signal of a natural fallow at L-band

HAL Id: hal-02819980

https://hal.inrae.fr/hal-02819980

Submitted on 6 Jun 2020

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Diurnal variations of the radiometric signal of a natural fallow at L-band

Maria-José Escorihuela, Yann H. Kerr, Patricia de Rosnay, Jean-Pierre Wigneron, Jean-Christophe Calvet

To cite this version:

Maria-José Escorihuela, Yann H. Kerr, Patricia de Rosnay, Jean-Pierre Wigneron, Jean-Christophe Calvet. Diurnal variations of the radiometric signal of a natural fallow at L-band. 6. SMOS Workshop, May 2006, Copenhagen, Denmark. 1 p., 2006. �hal-02819980�

Abstract Title

Diurnal variations of the radiometric signal of a natural fallow at L-Band Abstract Text

The SMOS mission aims at delivering global fields of sea surface

salinity and surface soil moisture using L band radiometry. Its overpass times are scheduled at 6 am and 6pm were dew and temperature gradients

might play an important role in emission. In the framework of the SMOS Mission preparation, the intensive and long term field experiment

SMOSREX is taking place in the south of France since 2001. A precision L-band dual polarization radiometer was especially designed for the experiment, and monitorizes continuously a natural fallow under

different incidence angles. Hence, SMOSREX provides an unique several

year dataset to study diurnal variations of vegetation radiometric signal. In this context, this study aims at (i) better understanding of the different effects influencing microwave signal at diurnal scale (ii) quantifying the effects of internal and external water content on

vegetation emission at L-band. For that study, field instrumentation was completed for the purpose of dew detection and with an optical sensor providing vegetation water content. We present a comparison of the different measurement techniques, describe the characteristics of the vegetation emission at diurnal scale and finally we quantify the effects of internal and external water content at the L-band emission.

Scientific Topic

04 Physics of the measurements Presentation Type

Poster Keywords

Keywords vegetation

Keywords dew

--- List of Authors

Escorihuela, M.J., CESBIO, FRANCE; de Rosnay, P, CESBIO, FRANCE;

Saleh,

K, INRA, FRANCE; Kerr, Y, CESBIO, FRANCE; de Jeu, R, Vrije Universiteit,

NETHERLANDS; Wigneron, JP, INRA, FRANCE; Calvet, JC, CNRM,

FRANCE