604 
purchasing power of nations varies widely. Per capita gross national product is one 
expression of purchasing power of a country, which in 1984 throughout the world ranged 
from $190 to $11,430 (US dollars), and the spread in these figures is increasing. It should 
be noted that many of the countries with lower per capita GNP are those that would 
(potentially) benefit most from resource monitoring tools, yet the price barrier effectively 
discourages their use of remote sensing data products [Specter, 1988]. At present, the 
shortage is covered to some extent by aid agencies, although this seems a fragile, arbitrary, 
inefficient, and unsatisfactory solution in the long run. If the General Assembly of the 
United Nations really means "non-discrimination" in spirit, then there is a need for 
improvement. In response, terms of availability for remote sensing data to be used for 
active environmental monitoring or sustainable development should move away from the 
market place approach, and move towards a progressive policy embodying a more 
reasonable cost basis for developing countries. 
Even though France, the United States, the European Space Agency, Canada, the 
Soviet Union, etc. base remote sensing data access on the market place approach, many of 
these same entities provide weather data to the public free of (direct) cost, and sell maps 
(some having been made from remotely sensed sources) for only a few dollars. These 
services are justified based on the large number and the distributed nature of the potential 
beneficiaries ... in short, a "public good" argument. For such data, the market place is not 
accepted as an appropriate forum for information supporting the public good. The rather 
fine distinction between remote sensing and weather data in this arena has been debated 
for many years. The differences would seem to be important when remote sensing data is 
used for resource exploitation by private firms who directly gain from their data cost 
investments. For environmental preservation and management, however, the situation is 
different. It would seem to us that no matter how technically differentiated in the past, the 
distinctions between weather and remote sensing data diminish in the context of active 
environmental monitoring: both serve the broader public interest. 
An Interim Conclusion 
The market place would seem to be justifiable for many applications of remote 
sensing. It should be evident from the foregoing discussion, however, that the market place 
is not rationally defensible in the context of active global environmental monitoring. It 
follows that the fundamental basis for availability of remote sensing data deserves to be 
reexamined and reformulated so as to more adequately account for the realities implied in 
respect of the public good. 
4. CONSTRUCTIVE TRENDS 
The underlying question of remote sensing data policy is the following: through what 
mechanism is the required quantity of data to be provided? It is reasonable to conclude 
that neither substantial nor wide-scale use of remote sensing data for active environmental