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TitleImpact of variable atmospheric water vapor content on AVHRR data corrections over land
AuthorCihlar, J; Tcherednichenko, I; Latifovic, R; Li, Z; Chen, J M
SourceIEEE Transactions on Geoscience and Remote Sensing (Institute of Electrical and Electronics Engineers) 39, 1, 2001 p. 173-180, Open Access logo Open Access
Alt SeriesEarth Sciences Sector, Contribution Series 20042778
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Mediapaper; on-line; digital
File formatpdf
AbstractThis paper explores the impact of the precipitable water content (PW) on the atmospheric corrections of optical satellite data over land. First, simulation runs are used to quantify the trends in red and near infrared parts of the electromagnetic spectrum. Second, Advanced Very High Resolution Radiometer (AVHRR) measurements obtained over Canada during the 1996 growing season, together with reanalyzed PW content data are employed to determine the actual impact of constant PW values. Third, various options in characterizing PW for atmospheric corrections of AVHRR composites are examined. It was found that, as expected, PW affects near-infrared radiation substantially more than red, although the latter is also altered; that additional, subtle interactions take place between PW, radiance levels, and viewing geometry that influence the retrieved surface reflectance; that spatial and temporal variation in PW caused changes in the normalized difference vegetation index up to 7.5% in relative terms during the peak green period; and that PW varies so substantially that pixel- and date-specific values need to be used for the atmospheric correction of AVHRR data. At the present, sub-daily gridded PW data sets from atmospheric data reanalysis projects are the only candidate source for such purpose.

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