Gerhard Meister

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The Collection 6 (C6) MODIS (Moderate Resolution Imaging Spectroradiometer) land and atmosphere data sets are scheduled for release in 2014. C6 contains significant revisions of the calibration approach to account for sensor aging. This analysis documents the presence of systematic temporal trends in the visible and near-infrared (500 m) bands of the(More)
The polarization correction for the Moderate-Resolution Imaging Spectroradiometer (MODIS) instruments on the Terra and Aqua satellites is described. The focus is on the prelaunch polarization characterization and on the derivation of polarization correction coefficients for the processing of ocean color data. The effect of the polarization correction is(More)
The NASA ocean color products of SeaWiFS and MODIS Aqua have been reprocessed in 2009 and 2010, respectively. This paper describes the changes to the calibration approach for MODIS Aqua. Due to a significant downward trend in the operational MODIS Aqua water-leaving radiances at 412nm, the previous calibration approach was no longer sufficient. The new(More)
Remotely sensed images with a pixel size of about 1 m can nowadays be acquired by airborne scanners and in the near future also by high resolution satellites. With such a high spatial resolution, remotely sensed data of urban areas can resolve structures like a roof into the different surface segments with different inclinations, e.g. in the case of a(More)
The Ocean Biology Processing Group (OBPG) at NASA's Goddard Space Flight Center is responsible for the processing and validation of oceanic optical property retrievals from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the Moderate Resolution Imaging Spectroradiometer (MODIS). A major goal of this activity is the production of a continuous ocean(More)
This paper presents results from analyzing hyperspectral BRDF data of grass lawn and watercress. The intensity of the hotspot as a function of wavelength is determined from fitting an empirical (or rather phenomenological) model to the data. The model consists of a lambertian, bowlshape, hotspot and forward scattering component. An analytical, theoretically(More)
{ Field-observed BRDFs for diierent land cover types are employed to derive a global BRDF/albedo database from land cover classiications. In a second step, AVHRR reeectance observations are used to reintroduce within-class variations into this database by tting the eld-observed BRDFs to the observed bidirectional re-ectances. These databases are useful(More)
I Abstract The reflectance of a surface usually depends on the angles, at which the surface is illuminated and viewed. The dependence can be described by the Bidirectional Reflectance Distribution Function BRDF. In this study, the BRDFs of several samples typically found in urban areas (roof tiles, asphalt, etc.) were measured at the European Goniometric(More)
Scanning radiometers on earth-orbiting satellites are used to measure the chlorophyll content of the oceans via analysis of the water-leaving radiances. These radiances are very sensitive to the atmospheric correction process, which in turn is polarization dependent. The image created by a scanning radiometer is usually composed of successive scans by two(More)