of various forms may require several different types of 
reduction before presentation for the evaluation. The fi- 
nal form of the data is another important consideration. 
Especially, for computer uses, a digital listing is the 
best. 
Certainly a very important aspect of any reduction pro- 
gram is the eonsideration of the flow of information.This 
area includes the planning of handling from receiving sta- 
tions to the processing centre and its facilities and then 
to the final user. Research is conducted in the whole tech 
nological flow of information. 
The most important investigations are: /1/ on board 
processing, and image data compression using different 
transformations /i.e.: Fast Fourier, Hadamard/; /2/ hard- 
vare development and modification; /3/ to overcome the fu- 
ture data overload, system requirements — including data 
relay satellites - are investigated. 
PHOTOIN TERPRETATION 
The rapid rise in the use of remote sensors has crea- 
ted a continuously increasing problem of a data overload 
which is entirely beyond the capabilities of human manipu- 
lation. As an example, about 80% of the data generated by 
spaceborne remote sensors are not used. Sophisticated com- 
puter interpretation techniques are considered as a possi- 
ble solution to this problem, however, no algorithm exists 
for the time being, which is capable of entirely deserib- 
ing intelligent human benaviour. To optimize the advanta- 
ges and shortcomings of man and machine, recent researches 
are oriented to create complex in*eractive systems for ima- 
ge analysis. Such systems involve real-time decision ma- 
king with man as an essential part of the system. Although 
many problems are encountered in designing a multifunc - 
tion system, they will not be considered in detail since 
they exceed the scope of this paper The major problems 
are related to the four phases of the evaluation process 
of a remote sensing system:/1/ definition of the objec- 
tive; /2/ ground data collection; /3/ statistical test