THE ESA EARTHNET PROGRAMME 
The Earthnet programme (Fig.1) was created to be the European Space Agency's 
focal points around which European scientists, technologists, and potential 
users of remote-sensing products could gather. To this end Earthnet's Lerms 
of reference include the acquisition, archiving, preprocessing and 
distribution of satellite remote-sensing data. The Earthnet-Programme 
Office (EPO) sited at the ESA-ESRIN establishment near Frascati in Italy, is 
responsible for programme management, monitoring of the network, user 
interface, data distribution, and preparation for the future activities in 
the remote-sensing disciplines. All the ESA Member and Associate-Member 
States (Austria, Belgium, Canada, Denmark, Federal Republic of Germany, 
France, Ireland, Italy, Netherlands, Norway, Spain, Sweden, Switzerland and 
the United Kingdom) take part in the programme. 
The data-acquisition and preprocessing facilities integrated into the 
network comprises three receiving and processing stations and two centres 
for processing Synthetic Aperture Radar (SAR) data. The stations at Fucino 
(Italy), Kiruna (Sweden) and Maspalomas (Canary Islands, Spain) acquire data 
from the Landsat system, and the station at Maspalomas data from the 
Nimbus-7 satellite (Fig.2). The two centres processing SAR data are at the 
Royal Aircraft Establishment (RAE), Farnborough (UK), and the German 
Aerospace Research Establishment (DFVLR), Oberpfaffenhofen (FRG). 
The Earthnet network characteristics can be summarised as follows : 
- The network is decentralised and relies on national facilities integrated 
into it. 
- Data acquisition, archiving and pre-processing is handled at the 
stations. (For ERS-1, archiving and off-line processing will be 
performed in ad-hoc facilities.) 
- Data are archived in raw form. Pre-processing is handled upon user 
request. 
- Quality control of products and software maintenance for the network are 
carried out at the facilities in Frascati. 
AVAILABLE DATA PRODUCTS 
After acquisition, the data are archived at the stations on high-density 
digital tapes (HDDTs), and are preprocessed only at the request of users. 
Data preprocessing, which is one of Earthnet's main tasks, is done at the 
Fucino and Kiruna stations for the Landsat, and at Maspalomas for Nimbus-7. 
Seasat data acquired aby the Oakhanger Station (UK) are converted into 
digital and photographic products at the RAE (UK) and DFVLR (FRG) processing 
centres (Fig.3). 
The 'standard' Earthnet products include digital data, on computer- 
compatible tapes (raw and system corrected), and photographic images 
(black-and-white films and prints, colour composites, optical enlargements 
at various scales). More complex and elaborate products can be supplied 
through the Earthnet distribution system. 
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