An airborne thermal scanner was designed in 1960 at the Swedish National Defense Research Institute and 
another scanner is the Thermovision equipment developed by AGA. In close co-operation with the Universities 
of Lund and Stockholm, studies have been carried out in the fields of urban planning, national resources, 
heated water, pollution problems, etc. 
In the field of multispectral measurements a 4-band Hasselblad “Package” is in use at the Geographical Survey 
Office in a project involving the universities and other organizations interested in studies of vegetation, water 
pollution, etc. At the University of Umea a research group is developing an instrument for determining spectral 
radiation signatures for use in ecological and oceanographical studies. Concerning RADAR, the Defense 
Research Institute is engaged in atmospheric sounding using 10 cm radar for studies within atmospheric 
physics, meteorology, etc. 
Techniques are being developed to detect moisture in the form of dew and atmospheric pollutants using 
tunable lasers. 
11. Geerders, P.J.F. 
Netherlands 
ELECTRONIC IMAGE ENHANCEMENT TECHNIQUES IN REMOTE SENSING 
Nowadays most information obtained by remote sensing techniques is recorded on photographic material. 
Although computers are employed to read and interpret photographs, the results of these experiments are not 
quite positive. The time necessary to perform the interpretation is rather long and the programmes are quite 
complicated. Visual interpretation is necessary in applications where time delay cannot be accepted. As the 
original information is transformed in such a way that it fits more the properties of the human visual system, 
electronic image enhancement can achieve better results in interpretation. Moreover this technique can be used 
to perform data reduction; a reduced" picture can therefore be read into the computer, if necessary. Although 
operational systems already are tested much work is still to be done. Some of these systems tested are: a 
contour-adder, which adds equal density lines to TV pictures; gamma-correction circuits, which change the 
grey scale; black and white to colour converters, which identify each grey level of the original picture with a 
colour and colour expanders, which expand an interesting part of the colour spectrum over the whole 
spectrum. 
The results of the tests made were very promising. 
12.  Gimbarzevsky, P. 
Canada 
THE ROLE OF AERIAL PHOTOGRAPHY IN THE DEVELOPMENT 
OF CANADIAN LAND CLASSIFICATION 
The Canada Land Inventory program initiated in 1963-64 was designed to provide a basis for resource and 
land use planning. Due to the extensive area involved (approximately one million square miles, or 1,600,000 
km?) extending through several physiographic regions from the Atlantic to the Pacific, the intensive use of 
aerial photographs has played an important role in the systematic land classification. The mapping of 
capability classes was based on photointerpretation of physical land characteristics and the land's capacity 
within a climatic region to produce a specified amount of field crops, forest products, to support a wildlife 
habitat, or to serve for recreation purposes. 
The photo interpretation techniques used in mapping of present land use and capability classification for 
agriculture, forestry, wildlife and recreation are briefly described and illustrated with typical working 
examples. 
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