For maps at the scale of 1 : 10,000 and 1 : 25,000 photographs 
are taken with aerial film cameras. Plotting is carried out from diaposi- 
tives prepared immediately after taking photography in order to preserve 
the originals and avoid errors due to film distortion. On diapositives pro- 
duced in such a way picture contrast is a little better than usual. 
Aerial survey photographs for large scale plans are taken on 
glass plates. The most convenient scale is determined according to plotting 
scale and is expressed by the formula Rs = 200 } Rk, with minor devi- 
ations depending on the type of camera and plotting instrument. 
From 1955 to the end of 1959, for various cartographic and 
economic purposes a total area of about 17,860 km? has been photographed, 
of which about 1,980 km? was for rectification purposes and 15,880 km? 
for stereophotogrammetric plotting. 
The equipment used for photogrammetric plotting and recti- 
fication of aerial photographs includes the following instruments: 
Autograph Wild A5, A6, A7 and A8 
Stereoplanigraph C8, Zeiss — Aerotopograph 
Stereoplanigraph, Carl Zeiss — Jena 
Stereotopograph Poivilliers, type B 
Stereotop Zeiss 
Rectifier Wild E-2 
First and second order instruments are used for photogrammetric plotting 
and production of maps and plans at the scales of 1 : 25,000, 1 : 10,000, 
1:5,000 and 1 : 2,500 
Photographs were usually taken at the scales of: 1 : 35,000, 
1 : 30,000, 1 : 20,000, 1 : 15,000, 1 : 12,000, 1 : 10,000 and 1: 8,000. First order 
stereoplotting instruments are also used for aerialtriangulation as well as 
for the plotting of terrestrial pairs of photographs. 
Third order instruments are used for special purposes in 
forestry, geology, etc. 
For 1:25,000 scale maps aerial photographs were usually 
taken at a scale of about 1 : 30,000 to 1 : 35,000, and for 1 : 10,000 scale 
maps photographs were taken at scales of 1 : 20,000 — 1 : 25,000. To pro- 
duce 1:5,000 plans, the scale for 18 X 18 picture size is 1:11,500 on 
films, and 1 : 14,000 for 14 X 14 picture size on plates. This depends on 
the size of standard sheet used for mapping (sheet size 45 X 60 cm). If 
the photographs are taken in the north-south direction, then two parallel 
strips with lateral overlap of 25°/o cover one sheet, while when they are 
taken in the east-west direction three strips of photographs cover two 
sheets. For 1 : 2,500 cadastral plans, the scale for 18 X 18 picture size on 
film is 1 : 8,500, and on plates 14 X 14 cm the scale is 1 : 10,500, which 
also depends on the size of the original sheets used for mapping. 
The method of Prof. Gruber is mostly used for relative orien- 
tation. In some specific cases the methods of Helmert, Poivilliers, Bach- 
mann, Jerie, Braum and others are also used. 
The existing triangulation network serves as a ground con- 
trol for stereoplotting and rectification. Control points are determined 
numerically by the antersection method, sometimes by traversing based 
on previously determined points. In some cases control points are marked 
before taking photography with white-washed stones (in rocky and carst 
ground) or with some other means (special marks). For topographic maps