This has an extremely important consequence. So far, in 
several countries, notably developing countries, digital image 
processing facilities, if at all available, are or were in a central 
place, usually in the capital. 
Access is difficult for a number of reasons, but one is that 
those around these facilities have become a class of 
knowledgeables, who guard their exclusive status. 
"Knowledge = power" and therefore they are not very eager to 
impart their knowledge onto others who might become 
competitors. The very high price of large image processing 
systems and spare parts was a safeguard to their exclusive 
status. It meant that (semi) (government) agencies and private 
consultants and other enterprises were dependent on the central 
facility. 
This is now changing: Image processing facilities of 
stand-alone capability based on PC's are now within the 
budgetary reach of institutes like the soil survey, the bureau 
of agriculture, the geological survey, but also the national 
mapping agency, the national planning bureau, and also the 
offices of local authorities. 
They can become independent of the central facility. Hard-and 
software developments are such that many of the functions are 
routine and hardware-based operations, more or less 
fool-proof, and do not require a special operator. The interpreter 
or the user can now do his own processing. 
It may be taken for granted that the industry will take care of 
market penetration, but that market is not the market of image 
processing and GIS. It is the market of the Personal Computer 
in general usage, complete with its collection of easy-selling 
software (games !, bookkeeping, spreadsheets, textprocessing). 
Only through their massive production and marketing these 
PC's have become affordable and increasingly powerful. 
Adaptation of these systems to digital image processing and 
GIS has resulted in an ample choice of systems available for the 
user today. ■ 
8.2 Base map updating 
Another interesting aspect is that topographic maps are often 
years out of date. If available, they are mostly the base on 
which interpretation data and other pertinent information is 
plotted. It becomes now possible - with the high resolution 
SPOT and IRS 1C and D data- to do rapid map updating, and 
the national mapping agency is no longer the only one who can 
do that! It can be done right at the resource agency (soils, 
geological, forestry services, regional and local planning offices 
etc.) It means that resource managing agencies at the local and 
regional (district, province) level, can do their own rapid map 
updating and produce reliable field maps as well as base maps 
for plotting the results of their surveys. 
8.3 Data supply 
RS data is now available on an operational basis, in the sense 
that the supplier guarantees continuity of the data stream for a 
given period. That means that for the first time now, it becomes 
a sensible proposition for mapping agencies, to use RS data 
(SPOT or Landsat) as an data source. So far, there was no 
question of it, as we were still in experimental and 
proof-of-concept phases. Still, the situation is rather uncertain 
as to the real operational continuity in data supply, especially 
from the Landsat series. 
8.4 Monitoring changes 
A new aspect, and a problem, is our inexperience in handling 
changes in situations or configurations at the earth's surface. 
We are used to the mapping of an existing situation, -which, by 
the way, is shown on a map that appears months if not years 
after the survey-, but not to the "mapping" (monitoring) of 
changes. 
Remote sensing, certainly in combination with scanned air 
photos and GIS, is capable of monitoring changes by the 
repetitivity of observations, and of showing them. 
8.5 Commercialisation 
Along with operationalisation comes commercialisation: 
Data are no longer being paid for by the (US) taxpayer, but by 
the user. That has given rise to a substantial increase in prices, 
bringing them to a realistic level from the almost-free level of 
the early days. Still, per square kilometer RS data is in the 
order of US$ 0.50 as against about US$ 2.50 for normal 
high-altitude aerial photography. 
But the number of sq. km per satellite scene is a constant, and 
the user may not need all of them. 
Users in Developing Countries usually complain about the cost 
of the data. It should be realized however, that the cost of image 
processing equipment has decreased dramatially. 
It should be noted that aerial photography retains, of course, its 
fully operational status as a data source. 
8.6 Resistance to institutional change 
In any established mapping or resource management, or 
planning agency, vested patterns of authority, (in)competence 
and job security coupled with bureaucracy are natural factors 
resisting change. 
Even if satellite data would be a reliable flow of basic data, then 
still it takes long and patient pushing before established routines 
in an agency are changed. 
Pushing too hard will also backfire. 
8.7 Security hocus-pocus. 
One way of exercising authority is declaring air photos and/or 
satellite or radar data of strategic value and imposing security 
restrictions on their use. Many potential users fight an uphill or 
losing battle against often senseless restrictions, and eventually 
give up. 
This happens in many countries and is an important reason for 
the under-utilization of aerospace remote sensing data in the 
widest sense, for purposes of mapmaking, resource evaluation 
and environmental management. 
The feeling of the present author is that international scientific 
associations and agencies in the field of remote sensing 
applications, are not enough aware of these factors. They