期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2007
卷号：XXXVI-7/C50
出版社：Copernicus Publications
摘要：A new instrument for passive remote sensing of sunlight-induced fluorescence took part in a series of airborne measurements during the summer 2005 (SEN2FLEX campaign). It measured for the first time the chlorophyll fluorescence emission over a succession of cultivated fields. The sensor is based on the Fraunhofer line discrimination principle, applied to the atmospheric oxygen absorption bands at 687nm and 760nm. Nadir viewing measurements made at various altitudes (300m-3000m) showed a continuous increase of the band depths when increasing the altitude. Among several radiative transfer models of the atmosphere, MODTRAN 4 was chosen to account for these altitude effects, because of its resolution (2cm-1) and its capability to describe multiple scattering. In order to validate the model, a data base was build up using ground measurements of the depth of the oxygen absorption band at 687 and 760 nm during a diurnal cycle. In this paper, we compare depths measured at the ground level with the MODTRAN 4 predictions. Local aerosol contents were retrieved from spectroradiometric measurements and included in the model. It is conclude that MODTRAN 4 is able to accurately describe the variation of the atmospheric oxygen absorption bands at 760 nm. The depth variation at 687 nm are also retrieved, but with a lower accuracy, due in part to the uncertainties of the spectral characteristics of the sensor. The sensitivity to several parameters, including aerosols, water content and ozone was studied
