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(including SAR) imaging from automatic spacecraft is very large. They have 
been given full coverage in large numbers of scientific and technical reports 
and publications. This is particularly true for aerial photography, a mature 
technique, which is used on a routine basis for all kinds of purposes in 
almost all parts of the world, except in those areas where prevailing 
climatological conditions limit the possibilities for photography. In those 
cases, non-photographic imaging techniques suited for all-weather conditions 
are used (SLAR and SAR). 
Satellite remote sensing of the environment and non-photographic airborne 
remote sensing (MSS, TIR, SLAR or SAR) do not replace aerial photography as 
such, even though they are better suited for some applications than conventional 
aerial photography. They permit better planning and optimization of aerial 
photography to suit specific purposes, to which has to be added an 
information content in part not obtainable by other observation methods 
(Refs. 2, 3). No wonder, that official documents highlight the prospects 
of remote sensing (Ref. 4) and that scientific conferences are held under 
titles as "Matching remote sensing technologies and their applications' or 
!'The Promise of Remote Sensing! (Refs. 5, 6). Even so, understanding of the 
full potential of remote sensing - for surveying and monitoring natural and 
human resources, the natural environment and the interaction between man 
and environment. - still has a long way to go before possibilities and 
limitations of the new technology can be accurately determined. To look 
upon remote sensing as a modified kind of aerial phetography involves at 
best the hazard to overlook new resource management opportunities (Ref. 3). 
To neglect consideration of the impact the new technology, in combination 
with new informatics and communication technologies,may have on administration, 
management structures and society creates risks for undesired societal 
transformations and disruptive developments (Refs. 2, 7). 
The relative value of satellite remote sensing data (as compared to other 
data collection techniques including aerial photography and airborne remote 
sensing) depends upon the nature of the phenomena to be: observed and the 
action to be undertaken by man. This is illustrated in Table 1, which gives 
a classification of subjects, processes and human categories in broad 
activities-(Refs. 2, 8, 9): 
Table 1; Relevance of satellite data for surveying the earth 
SURVEYING ACTIVITY 
  
  
static : dynamic dynamic 
MAPPING & CHANGE 
FIELD op MONITORING 
INVENTORY DETECTION 
detection, updating "maps", natural resources 
identification, studving processes, for resource 
description, civil defence, utilization, crop yield 
localization policing, rescue and prediction, environmental 
relief planning management of 
DISASTER HUMAN 
SURVEYING ACTIVITIES 
Liquid earth * ME +. 
Solid earth “sx %% ** 
Built-up earth de Ra oe od of oe 
Living earth ae ke ke 4 ea PII 
Volatile earth * v ** 
  
Activities refer to: what is where/what has happened/what is going on/what is going wrong 
Legend: **** very relevant — *** relevant — ** partially relevant — * slightly relevant 
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