B) MAPS ON SCALE SUPERIOR TO 1:25 000.
1. Cadastre and similar applications.
a) The photogrammetry is used in great extence in making maps
for taxation and planning of estates.
b) The scale used in these cadastral maps is 1:4000 and has been
proved by test to have an accuracy of + 0,2 % G.m.e. in open relati-
vely flat ground.
The taxation maps are single rectified photographs in suitable di-
vision of sheets without contour lines and coordinates. The only sup-
plementary measurements needed on the ground are the scale check
lines about one per each photo. Contents required in the maps or the
photo sheets as they are called, are: boundaries and bound stones of
estates, record numbers of estates and soil classification of open and
woodland ground.
c) The estate maps 1:4000 are gradually completed by above men-
tioned photo sheets.
2. Other topographie maps for various purposes.
a) The base scale of topographic maps in Finland is 1:20 000 with
equidistance of the contour lines 5 m. All topographic maps at present
are based on the controlled mosaic, contour lines and details being mea-
sured and investigated on the terrain. The mosaics are made on scale
1:10 000. The accuracy in height has proved to be about + 1,3 m G.m.e.
and in position about + 7 m G.m.e.
b) Maps for region and town planning have been made partly
by redressing of single photographs assembled to controlled mosaics
and by restitution of couples of stereoscopic plates (films) in Zeiss Ste-
reoplanigraph. In the former case the compilation scale usual has been
1:5000 and final maps on scale 1:2000 and 1:5000. In the latter case the
scale of final maps is usual 1:2000 or 1:4000 with the equidistance of
contour lines 1,0 and 2,5 m respectively. The accuracy in position of the
mosaic is about + 3,5 m and of the stereoscopic works about + 1 m.
The accuracy in height is about + 0,5 m.
c) Same as in point E.1.6.
d) Not at all.
e) In forestry there are used maps like mentioned in points
B.1.b.) and E.2.4).
f) In geology there are used maps equal with the former point.
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