On the Use of X-Band Weather Radar for Wind Field Retrieval in Coastal Zone

Abstract : This paper documents the study of the radar signature of the sea surface on the images collected by an X-band weather radar and its application to remote sensing of the coastal zone. The main radar parameters considered here are the reflectivity factor [which was converted into a normalized radar cross section (NRCS)], the differential reflectivity, and the mean radial velocity. Measurements of the NRCS in the vicinity of an instrumented offshore buoy allowed for identifying its variations with wind speed and relative direction, which are found to be consistent with the Georgia Institute of Technology (GIT) model and other measurements. A more accurate empirical model for the NRCS is developed. For moderate to strong winds, the mean radial velocity is linearly related to the radial component of the wind speed, showing the potentiality of weather radars to map the radial surface wind speed at the scale of a basin. The influence of surface currents is weak here but should be likely taken into account in other places with stronger currents. Measurements of the differential reflectivity are also consistent with other measurements made elsewhere for the polarization ratio. The analysis of radar data over the entire coverage could also be performed using surface wind estimates from a meteorological model. Similar but less accurate results are obtained for the NRCS and the mean radial velocity. The extra spatial variability not due to wind speed variations is identified. An inversion procedure is proposed to recover the wind vector field from radar measurements after calibration of the NRCS values. Results are promising and pave the way to the concept of weather radar for ocean remote sensing.
Type de document :
Article dans une revue
Journal of Atmospheric and Oceanic Technology, American Meteorological Society, 2016, 33 (5), pp.899-917. 〈10.1175/JTECH-D-15-0206.1〉
Liste complète des métadonnées

https://hal.archives-ouvertes.fr/hal-01443606
Contributeur : Valerie Michotey <>
Soumis le : lundi 23 janvier 2017 - 11:39:45
Dernière modification le : jeudi 7 février 2019 - 15:50:48

Identifiants

Citation

P. Forget, M. Saillard, Charles-Antoine Guérin, J. Testud, E. Le Bouar. On the Use of X-Band Weather Radar for Wind Field Retrieval in Coastal Zone. Journal of Atmospheric and Oceanic Technology, American Meteorological Society, 2016, 33 (5), pp.899-917. 〈10.1175/JTECH-D-15-0206.1〉. 〈hal-01443606〉

Partager

Métriques

Consultations de la notice

141