Paper Info
Title
An angular-dependent split-window equation for SST retrieval from off-nadir observations
Abstract
An angular-dependent split-window equation is proposed for determining the Sea Surface Temperature (SST) at any observation angle, including large viewing angles at the image edges of satellite sensors with wide swaths. The proposed equation takes into account the angular dependences of the atmospheric correction and also the emissivity correction. An explicit dependence on the SSE is considered in an independent term. The inclusion of such a term is not common in the current operational SST algorithms but we consider it appropriate taking into account the non-blackness of the sea surface emission for large angles and also the dependence on wind speed. The equation has been adapted to the Moderate Resolution Imaging Spectrometer (MODIS) on board EOS-Terra and EOS- Aqua, with at surface observation angles up to 65deg, and to the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board MSG, with even larger observation angles. Angular- dependent coefficients were estimated for the atmospheric and emissivity terms using synthetic data generated from a series of cloud-free, latitude-equally distributed radio sounding profiles. The use of the proposed expression requires as input data: at- sensor brightness temperatures for the split-window bands, the observation angle at each pixel, an estimate of the water vapor content and accurate SSE values for both channels. A comparison of the results of the equation for MODIS with in-situ measurements gathered from different NOAA ships and buoys placed around the world showed an accuracy of about plusmn 0.3 K for any observation angle, including off-nadir viewings, while the MODIS operational algorithm leaded to an error of plusmn 0.7 K at large angles. The proposed technique is mainly recommended to retrieve SST from observations at large viewing angles, since similar values are obtained by the current operational algorithms for nadir viewings.
Year
DOI
Venue
2007
10.1109/IGARSS.2007.4422948
Barcelona
Keywords
Field
DocType
atmospheric humidity,atmospheric optics,ocean temperature,oceanographic techniques,seawater,wind,EOS-Aqua,EOS-Terra,MODIS,SST retrieval,atmospheric correction,emissivity correction,moderate resolution imaging spectrometer,off-nadir observations,radio sounding profile,sea surface emission,sea surface temperature,split window equation,water vapor content,wind speed,MODIS-EOSTerra/Aqua,SEVIRI-MSG,Sea surface temperature,sea surface emissivity,split-window equation
Nadir,Atmospheric correction,Atmospheric optics,Satellite,Sea surface temperature,Depth sounding,Computer science,Remote sensing,Emissivity,Brightness
Conference
ISSN
ISBN
Citations 
2153-6996
978-1-4244-1212-9
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Niclòs, R.100.34
César Coll29216.27
Vicente Caselles313922.32
María José Estrela400.34