DocumentCode :
2666332
Title :
Synchronous atmospheric correction and SST retrieval by AATSR data
Author :
Wenjie, Fan ; Zhaoliang, Li ; Xiru, Xu
Author_Institution :
Peking Univ., Beijing
fYear :
2007
fDate :
23-28 July 2007
Firstpage :
1000
Lastpage :
1003
Abstract :
The water vapor is the main absorb substance of the atmosphere in thermal infrared bands, but the distribution of water vapor amount in the ground varied greatly, so one radio sounding couldn´t represent the water vapor distribution of different pixel in one image. AATSR (Advanced Along-Track Scanning Radiometer) sensor could provide radiance measurements of two channels at two observation angles. So it is possible to retrieve the atmosphere parameters and SST (Sea Surface temperature) synchronously. In order to make the system of equations determined, the two atmosphere parameters that could express whole atmosphere profiles must be confirmed. As the retrieval accuracy is requested, the surface reflected atmospheric downward radiance effect couldn´t be ignored. A climatologically data set of 1761 different radio soundings, the SATIGR database, have been used to develop a new atmospheric correction method, the two atmosphere parameters have been proved that could represent the transmittance, atmospheric upward radiance and downward radiance of different wave band and different view angle, they are the transmittance and atmospheric upward radiance of 11 mum at the nadir view angle. Introducing the appropriate sea surface BRDF model, the emissivity and the reflected downward radiance can be calculated precisely. So the SST, wind speed, and two atmosphere parameters are retrieved by Broyden iteration method, when the initial values are found using LUT (look up table) method. Simulations showed :(1) the physics-based algorithm described in this paper could provide more accurate calculation of atmospheric effect. Compared with split window method, the retrieval error of SST is little. (2) The new downwelling atmospheric radiance correct method described in this paper could provide more precise calculation of atmospheric effects. The field test using ATSR-2 (Along-Track Scanning Radiometer- 2) DATA proved this new algorithm can improve the retrieval accuracy significant- ly
Keywords :
atmospheric humidity; atmospheric optics; atmospheric radiation; atmospheric techniques; infrared imaging; ocean temperature; radiometers; remote sensing; AATSR; Advanced Along-Track Scanning Radiometer; Broyden iteration method; SATIGR database; SST retrieval; atmospheric upward radiance; look up table method; radio sounding; sea surface BRDF model; sea surface temperature; surface reflected atmospheric downward radiance effect; synchronous atmospheric correction; thermal infrared imaging; water vapor distribution; wind speed; Acoustic sensors; Atmosphere; Atmospheric modeling; Atmospheric waves; Information retrieval; Infrared imaging; Ocean temperature; Pixel; Radiometry; Sea surface; AATSR; Atmospheric correction; SST;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Geoscience and Remote Sensing Symposium, 2007. IGARSS 2007. IEEE International
Conference_Location :
Barcelona
Print_ISBN :
978-1-4244-1211-2
Electronic_ISBN :
978-1-4244-1212-9
Type :
conf
DOI :
10.1109/IGARSS.2007.4422969
Filename :
4422969
Link To Document :
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