Surface reflectivity spectra derived from GOME data

AUTHORS:
Robert Koelemeijer (1), Piet Stammes (1), and Daphne Stam (1,2)

(1) Royal Netherlands Meteorological Institute (KNMI)
    P.O. Box 201, 3730 AE De Bilt, The Netherlands
(2) Faculty of Physics and Astronomy, Free University (VUA),
    De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands


ABSTRACT TEXT:

Knowledge of the spectral surface albedo of the Earth is important for the
interpretation of satellite measurements and for understanding the Earth's
radiation budget. Differences between the spectral behaviour of the surface
and that of the atmosphere are often used in satellite retrieval
algorithms, in particular in cloud detection algorithms.
In April 1995, the Global Ozone Monitoring Experiment (GOME) was launched on
board of the ERS-2. GOME is a spectrometer measuring the Earth's reflectivity
between 240 and 790 nm with a spectral resolution of 0.2-0.4 nm.
In this presentation, spectral reflectivity measurements from GOME are
shown for four typical cloud-free scenes, namely over the Saharan desert,
the Atlantic Ocean, ice-snow (Greenland), and rain-forest (Brazil).
For the derivation of surface reflectivity from the spectra measured at the
top of atmosphere, atmospheric correction is necessary.
Therefore, atmospheric radiative transfer calculations have been performed
with the Doubling-Adding KNMI (DAK) model. Using these calculations, surface
reflectivities have been derived at a number of wavelengths.
We will show the GOME data can be used to derive spectrally resolved surface
reflectivities on a global scale.


KEY WORDS:
ERS-2, GOME, spectral, reflectivity, surface

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry