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Improving the accuracy of sea surface salinity retrieval using GNSS‐R data to correct the sea state effect
Author(s) -
Valencia E.,
Camps A.,
RodriguezAlvarez N.,
RamosPerez I.,
BoschLluis X.,
Park H.
Publication year - 2011
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/2011rs004688
Subject(s) - gnss applications , remote sensing , sea state , environmental science , brightness , brightness temperature , reflectometry , radiometry , meteorology , computer science , geology , global positioning system , geography , physics , optics , telecommunications , time domain , computer vision
Reflectometry using GNSS signals of opportunity (GNSS‐R) has stood as a powerful technique for ocean remote sensing. Particularly, the use of these techniques has been proposed to retrieve sea state information (i.e. sea surface roughness) among other applications. Precise knowledge of the sea state is a key issue to process L‐band radiometric measurements for sea surface salinity retrieval. It has been recently shown that GNSS‐R data can be directly linked to the brightness temperature variations caused by the sea state effect, without the use of emission/scattering models or sea spectra models. In this study, this approach is applied to CoSMOS 2007 flights data. Firstly, the radiometric and GNSS‐R data sets are presented. Secondly, measured brightness temperature is corrected using the collocated GNSS‐R data. In particular, the area under the normalized waveforms is used to directly compute the required brightness temperature correction. Thirdly, the salinity retrievals are presented (achieving an error reduction from 2.8 psu for the raw measurements down to 0.51 psu). Finally, the obtained results are compared with the WISE correction approach, based on the wind speed correction, and the conclusions of this work are presented.