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Special oceanographic demands, processing and distribution 
  
Oceanographers can use RS data at three moments: 
- before an expedition for planning, 
- during an expedition to be sure to be.at the right spot, 
- after an expedition, to "fill in the gaps" between their 
point or line measurements. 
"Before" and "after", means using retrospective data; "during the 
expedition" means using either an on-board receiving system or 
information given from land-based receiving stations by telephone, 
fac-simile or telex. 
Since the contrasts sought are sometimes very small, care should 
be taken in the processing to preserve these small differences 
and to be able to reproduce them in the format required. 
Concerning formats, it is also important to keep in mind that one 
of the activities of oceanographers is to compare data from 
different areas and from different time periods. The format of RS 
data should be as such as to maintain a constant quality over a 
iong period of time and should be compatible with formats from 
other sources. 
Before retrospective data can be ordered, the oceanographer needs 
a good and cheap quick-look to see whether the phenomenae he is 
looking.for, are actually present in that.image. 
The first experience 
  
Imagery from Landsat, Skylab and other US platforms 
indication of the potential of RS for oceanography. 
Landsat data can be very useful, if the appropriate enhancement 
can be made. In the Netherlands, a small project is under way to 
investigate whether it is possible to find a standard enhancement 
for Landsat data over the Southern North Sea. 
The optical sensors seem to detect chlorophyll, sediments and 
pollution. Infrared sensors give the distribution of the Sea 
Surface Temperature (SST). 
SEASAT gave a tremendous amount of data, in spite of its short 
lifetime of 100 days. Still much of the data is not analysed. 
data indicated the possibility of obtaining data on waves, 
currents and winds by the use of microwave techniques. The 
Synthetic Aperture Radar showed interesting but largely yet 
unexplained patterns over the sea. 
gave a first 
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For the oceanographers today two alternatives exist, besides 
Landsat: 
- the experimental NIMBUS-7 with the Coastal Zone Color Scanner, 
a multispectral scanner intended to analyse the color of the 
sea to obtain chlorophyll,sediment and yellow outstance content. 
It took one year after the launch to get the first CZCS data to 
the oceanographers. Much of the data is yet unanalyzed, partly 
because of the lack of appropriate processing algorithms for 
Specific sea areas. CZCS data of Europe is split over three 
archives at this moment of which the contents are not all known. 
- The operational meteorological satellites, producing visible and 
infrared data. This data is available through most meteorolo- 
gical offices. The enhancements, necessary to make the data 
useful for oceanography, are applied only in a few cases. 
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