— Coordinated aerial survey have been used for various 
purposes in our country. In this we have had to coordinate the scale of 
the photographs, the season when the photographs were taken, types of 
photomaterials, the use of filters etc. For such porposes efforts are being 
made to realize a detailed specific signalisation in forest areas. 
— Independent mapping works (maps at the sceales of 
1:10,000 and 1: 20,000) are carried out with the aid of approximate plot- 
ting instruments (camera lucida — Zeiss, Stereoscope with parallax bar, 
Stereotop), for areas where 1:10,000 and 1:20,000 scale maps did not 
yet exist. 
— The use of aerial photographs for interpretation purposes, 
such as descriptions of forest strands, vegetational mapping, soil map- 
ping etc. 
The use of aerial photographs for geological purposes has 
been on the increase since 1956, especially in connection with regional 
geological mapping at the scale of 1 : 50,000. For the preparation of preli- 
minary photogeological maps as guides for field work, photographs on 
the scale of about 1 : 30,000 are stereoscopically examined. The results of 
the photogeological examination are most frequently transferred visually 
to the topographic map, or in some cases a regular photogeological map is 
made by means of radial triangulation (slotted templets method) and 
sketchmaster. As a basis for field mapping, enlargements at the scale of 
about 1:13,000 are in wide use, serving instead of topographic maps. 
Photogeological methods are making rapid progress, and a small center 
for their development is now in construction. 
The basic characteristic of photogrammetric activity in our coun- 
try in the period since 1956 has been the extensive application of photo- 
grammetry in making cadastral maps on the scale of 1:2,500 with topo- 
graphy shown by contour lines, at 2,5 m contour intervals. In this period, 
with the aid of photogrammetry, cadastral maps have been made for an 
area of 1,000.000 ha and thus the photogrammetric method has become 
almost the only method used in cadastral surveying.