GRAS provide satellite data in near real time as well as archive data
from various medium to low resolution satellite sensors, e.g. MODIS
Aqua and Terra, ENVISAT MERIS, NOAA, Meteosat and other medium to low
resolution sensors. Based on data from these sensors it is possible to
derive a numbers of different products. A few selected is described
below.
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True and false colour composites
Very
often a simple colour composite is just as valuable as a derived
product. GRAS can deliver global near real-time quicklooks of e.g. MODIS
typically within a few hours after acquisition.
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Sea Surface Temperature (SST)
Sea
Surface Temperature can be used for a wide range of applications e.g.
location of fronts and currents, assimilation and validation of
oceanographic models, meteorological modelling and temporal analysis of
Sea Surface Temperature for global change studies. |
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Chlorophyll-a concentration (for algae
monitoring)
Chlorophyll-a maps can be used for a wide range
of applications e.g. indicator of water quality, warning systems for
harmful algae blooms, assimilation and validation of oceanographic
models and temporal analysis of algae distribution patterns as
indicators of changes to the aquatic environment e.g. due to
eutrophication. |
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Diffuse attenuation coefficient (secchi depth)
The
diffuse attenuation coefficient (K490) is an indicator of the turbidity
of the water column – how visible light in the blue-green part of the
spectrum penetrates the water column. The diffuse attenuation
coefficient maps can be used for a wide range of applications related to
water quality and turbidity. |
The parameters mentioned above are especially suitable for monitoring
the marine environment where low resolution satellites can monitor
larges areas several times a day.
GRAS has profound expertise in handling and automating the routines
involved in data processing. Procedures such as calibration, geometric
rectification and format conversion are performed automatically and the
data can be available to the client as soon as 30 minutes after the
satellite overpass. The data are transferred via ftp and email alerts
are sent out when new data become available. All data delivered in the
format requested by the client and is ready for any further GIS
analysis.