Journal of Geodesy and Geoinformation Science ›› 2021, Vol. 4 ›› Issue (1): 30-37.doi: 10.11947/j.JGGS.2021.0104

• Special Issue • Previous Articles     Next Articles

SAR Azimuth Cut-off to Estimate Wind Speed under High Wind Regimes

Valeria CORCIONE1(),Ferdinando NUNZIATA1,Marcos PORTABELLA2,Giuseppe GRIECO3,Xiaofeng YANG4,Maurizio MIGLIACCIO1   

  1. 1. Università degli Studi di Napoli Parthenope, Dipartimento di Ingegneria, Naples 80133, Italy
    2. The institute of Marine Sciences (ICM-CSIC), Barcelona 08003, Spain
    3. Koninklijk Nederlands Meterologisch Instituut (KNMI), De Bilt 3731, The Netherlands
    4. State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2020-10-10 Accepted:2020-12-25 Online:2021-03-20 Published:2021-04-06
  • About author:Valeria CORCIONE (1989-), female, post?doctoral student, majors in electromagnetic modeling, SAR data analysis, and ocean remote sensing. E-mail: valeria.corcione@uniparthenope.it

Abstract:

In this study, the azimuth cut-off method, typically used for SAR moderate wind speed estimation purposes, is analyzed under high wind regimes. Firstly, the importance of the pixel spacing, the size of the boxes selected for Synthetic Aperture Radar (SAR) image partitioning and the image texture in terms of homogeneities are discussed by considering their influence on the azimuth cut-off (λc) estimation. Secondly, a quality control analysis of the reliability of λc is carried out by evaluating the distance between the autocorrelation functions (ACF) and their correspondent fittings. This analysis points out the importance of filtering out the unreliable and unfeasible λc values in order to improve the wind speed estimation. The quality control procedure is based on a x2 test, applied on a large Sentinel-1A dataset. The soundness of the test is verified by an increment in terms of correlation between λc estimations and wind speed values. This approach is, then, applied under high wind regimes, i.e., tropical cyclones.

Key words: SAR; wind speed; azimuth cut-off; significant wave height