In the identification of European interest and in the 
definition of the elements of a European remote sensing space 
programme, ESA activities have concentrated on the following 
four aspects 
- definition of mission objectives and measurement 
requirements (1); 
- gaining access to already available remote sensing 
satellite data through the Earthnet programme(2); 
- preparation of remote sensing experiments for use in 
Spacelab (4, 5); 
- definition of the elements of the future European remote 
sensing satellite peogrammes (6). 
Each of these aspects is described in detail in the 
following sections. 
2. OVERALL MISSION OBJECTIVES 
  
Many different types of remote sensing satellite systems 
can be envisaged for both regional and global applications; 
these include 
a) Regional satellites 
  
- to monitor dynamic features in developed regions such 
as Europe; 
- to provide basic resources information for developing 
regions to be used within the framework of develo»- 
ment aid programmes. 
b) Global satellites 
  
- to monitor the global oceans; 
- to monitor the global atmosphere, in particular with 
respect to the climate and climate changes, and air 
quality measurements; 
- to map global resources such as basic food supplies, 
soils and forests. 
The extent of European involvement will depend on inter- 
nal European priorities; it seems clear, however, that high 
priority will be given initially to the implementation of 
regional space systems providing data that can be applied 
both in Europe and within the framework of development aid 
programmes. The key missions for such a satellite system 
are 
      
  
  
     
   
    
    
    
    
    
    
     
     
    
   
   
    
   
   
     
  
      
ii