Publications des scientifiques de l'IRD

Fatras C., Borderies P., Frappart F., Mougin E., Blumstein D., Nino Fernando. (2018). Impact of surface soil moisture variations on radar altimetry echoes at Ku and Ka bands in semi-arid areas. Remote Sensing, 10 (4), p. art. 582 [23 p.]. ISSN 2072-4292.

Titre du document
Impact of surface soil moisture variations on radar altimetry echoes at Ku and Ka bands in semi-arid areas
Année de publication
2018
Type de document
Article référencé dans le Web of Science WOS:000435187500094
Auteurs
Fatras C., Borderies P., Frappart F., Mougin E., Blumstein D., Nino Fernando
Source
Remote Sensing, 2018, 10 (4), p. art. 582 [23 p.] ISSN 2072-4292
Radar altimetry provides information on the topography of the Earth surface. It is commonly used for the monitoring not only sea surface height but also ice sheets topography and inland water levels. The radar altimetry backscattering coefficient, which depends on surface roughness and water content, can be related to surface properties such as surface soil moisture content. In this study, the influence of surface soil moisture on the radar altimetry echo and backscattering coefficient is analyzed over semi-arid areas. A semi-empirical model of the soil's complex dielectric permittivity that takes into account that small-scale roughness and large-scale topography was developed to simulate the radar echoes. It was validated using waveforms acquired at Ku and Ka-bands by ENVISAT RA-2 and SARAL AltiKa respectively over several sites in Mali. Correlation coefficients ranging from 0.66 to 0.94 at Ku-band and from 0.27 to 0.96 at Ka-band were found. The increase in surface soil moisture from 0.02 to 0.4 (i. e., the typical range of variations in semi-arid areas) increase the backscattering from 10 to 15 dB between the core of the dry and the maximum of the rainy seasons.
Plan de classement
Bioclimatologie [072] ; Télédétection [126]
Description Géographique
MALI ; SAHEL ; AFRIQUE DE L'OUEST ; ZONE SEMIARIDE
Localisation
Fonds IRD [F B010073602]
Identifiant IRD
fdi:010073602
Contact
  • Coordonnées :
    IST / IRD Ile-de-France
    32 avenue Henri Varagnat
    93140 Bondy Cedex
    France
    Horizon Pleins textes
  •