Preliminary validation of the NSCAT-5 Geophysical model function

• Main Authors: Lin, Wenming, Portabella, Marcos, Stoffelen, Ad, Verhoef, Anton, Wang, Zhixiong
• Format: Report
• Language: unknown
• Published: 2017
• Subjects: Indian; Sea ice
• Online Access: http://hdl.handle.net/10261/158565

16 pages, 8 figures Recent developments on the wind geophysical model function (GMF) of Ku-band scatterometers include a sea surface temperature (SST) dependent term. It has been found that the SST effects on the radar backscatter are wind speed dependent and more pronounced in vertical polarization (VV) than in horizontal polarisation (HH) at higher incidence angles, and are mainly relevant at radar wavelengths smaller than C-band. The new Ku-band GMF, NSCAT-5, is based on a physical model and RapidScat radar backscatter measurements, which are only available at two incidence angles, i.e., 48.8⁰ and 55.2⁰, for HH and VV beams, respectively. The aim of this study is to perform a preliminary verification of the NSCAT-5 GMF at similar incidence angles, using data from the recently-launched Indian SCATSat-1, which operates at 49.1⁰ (HH) and 57.9⁰ (VV) incidence angle. A more comprehensive validation will be carried out later in 2017, as part of a follow-on CDOP-3 VSA activity, including a more recent calibration version (1.2.3) and so-called stress-equivalent winds The work has been funded under the EUMETSAT Ocean and Sea Ice (OSI) Satellite Application Facility (SAF) Associated Scientist project (reference OSI_AVS_17_01) Peer Reviewed