OVERALL DESCRIPTION OF EARTHNET AND RELEVANT. ARRANGEMENTS 
MADE BY THE EUROPEAN SPACE AGENCY (ESA) 
H.Kaltenecker, ESA, Toulouse, France 
l. Earthnet - description of tasks and present situation 
  
Earthnet has been set up as the European network for the acquisition, pre- 
processing, archiving and distribution of data from remote sensing satellites. 
At present the system is oriented towards the acquisition of data supplied 
by US satellites but it will have to be the nucleus of the ground segment 
of the future European remote sensing space programme. Its aim is to provide 
a coherent service of all activities from acquisition of raw data to 
distribution of preprocessed data and to promote in this way the creation 
of a strong and well-structured user community. 
Logically, the activities of the first few years are focused on the 
establishment of a basic network of acquisition stations and on the provi- 
sion of a limited set of standardised products to the users. The result of 
this initial effort should be the establishment of a basic European 
capacity to handle data from remote sensing satellites, both American and 
European. 
Once the basic capacity established, the effort will have to be switched 
to the provision of higher standard products tailored to the needs of the 
users. Operational use of satellite remote sensing data will require the 
possibility for accurate comparison of images from different times and 
from different sensors and/or satellites and, therefore, the establish- 
ment of a precision preprocessing capability. The level of investments 
necessary for setting up this capability will possibly result in the nead 
for setting up a centralised precision preprocessing facility. Technical 
considerations could also require the creation of a centralised remote 
sensing data archive. (Attachment 1). 
In setting up the basic network of acquisition stations, Earthnet aims 
at covering three basic types of remote sensing satellites: 
a) Satellites focusing primarily on land applications and working, at 
least until 1985, in the visible and infrared parts of the spectrum. 
In this field the Landsat series of satellites have been providing 
data for more than 5 years and, through the launches of Landsat-C 
(5 March 1978), Landsat-D (1981) and Landsat-D' (1984), continuous 
supply of this type of data is assured up to the late 1980s. The 
main development trend for future spacecraft is towards higher ground 
resolution and, consequently, higher data rates. The stations covering 
the Landsat satellites (Fucino * Kiruna) will also have to acquire 
data from future European remote sensing satellites. In view of this 
long term involvement, a basic Earthnet investment in the Fucino and 
Kiruna stations is justified. Details of Earthnet's implication in the 
Fucino and Kiruna set-ups are given in Chapter II.