FINLAND 5 
Topographic Map 1: 100000 
The revision of the production method of the Topographic Map 1 : 100 000 is 
just now going on, but the sheets which have been published until this are made 
in the same way which was described in the previous Report. The mapping of 
contour lines is now carried out mostly with Stereotop instruments. The reformation 
of the graphic form of the Topographic Map is also under consideration. 
The annual production has been recently 6—10 sheets, 1200 km? each. 
A sample of the Topographic Map is shown in the appendix (picture 8). 
General Map 1 : 400000 
This map is mostly derived from larger-scale maps, but during the last years 
some sheets have also been made directly from controlled mosaics. A sample of the 
General Map in its recent printed form is shown in the appendix (picture 7). 
Mapping for development planning 
Maps on which the development plans of rural agglomerations are based are 
made in the scale 1 : 2000 with 1 meter contour interval. These maps are produced 
by the Plan Survey Division of the General Survey Office as well as by some private 
surveying companies. 
The ground control of these maps consists of triangulation and traverse points 
(about 20 points per km?). Control points and boundary marks are signalized before 
aerial photography so that they can be identified on photographs. 'The photographs 
are taken mostly in scale 1 : 7000—1 : 10 000 with a wide-angle camera. During 
the reporting period the stereoscopic plotting method has become taken into use 
almost exclusively, and the maps are plotted with autograph Wild A8. Photograph 
interpretation is done in the field on enlarged copies, and such features and boundary 
marks which cannot be seen on photographs are surveyed by using the field methods. 
Some completion levelling must also be done on thickly wooded areas. 
During the years 1956—59 total 1117 km? has been mapped for development 
planning by using stereoscopic plotting instruments. The evolution shows a strong 
increase in stereoscopic mapping, so that e.g. in the year 1959 345 km? was mapped 
by using this method, compared with only 152 km? in 1956. 
During the last years some mappings for urban development plans have been 
made in the scale 1 : 500 with 1 meter contour interval. The results of these works, 
which were commissioned by some cities and towns, were very favourable. The 
photographs for this purpose were taken in the scale 1 : 3000 with a normal-angle 
camera and the plotting was made with stereoplanigraph or autograph A8. 
Cadastral Surveys 
Before the year 1956 the photogrammetric methods were not employed in 
cadastral surveys, except in some test works. During the reporting period a 
considerable development has taken place in this line, although the methods and 
organization of the mapping works still require more thorough investigation. 
The largest objects of the photogrammetric mapping in cadastral survey have 
been the areas where a new division of farm land shall be accomplished. The largest 
of such areas comprise hundreds of square kilometres. The ground control is made 
with triangulation and completed with traverse points until a density of about one 
point pro three stereo models has been obtained. The control points and boundary 
marks have been signalized and the photographs were taken in scale 1 : 8000— 
1:20 000 with a normal-angle or a wide-angle camera depending on the local 
circumstances. The control extension is made with a stereoplanigraph, and at the 
same time also the coordinates of all boundary marks are measured.