3.6. Land Consolodation Maps 
For the needs of the land consolidation which began in 
1911 but was carried out on a mass footing in Bulgaria 
during the period 1932-1942, land consolidation maps at 
scale of 1:2000 are compilated for some lands with total 
area of about 1.5 thousand sq. km. 
4. PHOTOGRAMMETRY 
4.1. The Beginning 
Bulgaria was probably the first country on the Balkan 
Peninsula to begin to apply photogrammetry. Terrestrial 
photogrammetric photographs were taken during 1907- 
1908 and were plotted in the Vienna Cartographic 
Institute by Eduard von Orel by means of a 
Stereoautograph designed by him. During the Balkan 
War (1912) and the World War | (1914-1918) aerial and 
terrestrial photographs were taken for military 
reconnaissance and road construction. 
More considerable attempt to apply terrestrial 
photogrammetry for the purpose of compilation a 
topographic map at scale of 1:25 000 was done in 1928. 
For the same purpose in 1930 began the implementation 
of single-image aerial photogrammetry and in 1940 of 
aerial stereophotogrammetry. For large-scale mapping 
single-image photogrammetry was applied after the end 
of World War ll and stereophotogrammetry - since 1954. 
4.2. Current Practice 
The aerial photogrammetry for civil production purposes 
in Bulgaria is concentrated in the following state 
enterprises: 
Geoplanproject Co., Sofia, 
Geodesia Co., Plovdiv, 
National Center of Cadastre Ltd., Sofia, 
Research in Geodesy and Photogrammetry Ltd., 
Sofia, 
Patproject Ltd. Sofia, 
Transproject Ltd. Sofia. 
Geoplanproject and Geodesia implement analogue 
stereoplotting of aerophotographs for compilation and 
revision rural and urban topographic maps at scales of 10 
000 up to 1:500. The National Center of Cadastre makes 
orthophotomaps at scales of 1:10 000 up to 1:2000. 
Research in Geodesy and Photogrammetry Ltd. 
accomplishes mainly specific photogrammetric works. 
Patproject and Transproject make maps at scales of 
1:2000, 1:1000 and larger, as well as digital models for 
the purposes of design and reconstruction of motor-ways 
for the purposes of design and reconstruction of motor- 
ways, railways and structures as well as for inventory of 
the road and railway network. 
4.3. The Place of Photogrammetry 
The place of photogrammetry in the land reform and 
cadastre in Bulgaria is determined mainly by six of its 
82 
multiple potentials: 
(i) Use of retrospective aerial photographs taken over the 
territory of Bulgaria for compilation of the topographic 
map at 1:25 000 scale before pooling of private farms 
into large collective farms. These aerial photographs 
are taken by normal-angle aerial survey camera (focal 
length 21 cm, format 18x18 cm) and are at 
approximate scale of 1:20 000. In the prevailing cases 
real boundaries of ownership at that time in mountain 
and hilly regions can be distinguished on them, i.e. 
where presumably these boundaries have been 
preserved up to now. 
(ii) Production of large scale orthophotomaps without 
contours as basis of the rural cadastre. The 
orthophotomap is cheaper and is produced 
considerably faster than the conventional topographic 
map which make it more up-to-date. The semantic 
information contained on it is of the same quality and 
quantity as that on the aerial photographs from which 
it is made. 
(il) Production and revision of very large-scale 
topographic maps in graphical and digital forms as 
basis of urban cadastre. This is a slower and more 
expensive process but it is inevitable in view of its 
high precision necessary for the compilation and 
updating of the respective graphical and digital maps. 
(iv) Production of photomosaics and other intermediate 
photogrammetric products for the purposes of the 
land reform. The photogrammetry has the advantage 
that from the instant of taking the aerial photography 
up to the production of the final product for which it is 
intended, several intermediate products can be made 
with different accuracy, serving some intermediate 
phases of the land reform. 
(v) Determination of terrain points by aerial triangulation 
for the needs of land reform and cadastre. 
Photogrammetry disposes of powerful means for high 
precision determination of points on the terrain. 
(vi) Numerical mapping of aerial photographs for 
compilation of land maps at scale of 1:5000 and 
larger, necessary for the restitution of ownership of 
agricultural lands in the existing real boundaries 
mainly in mountain and hilly regions of the country. 
Here one should add also the topographic map at scale 
of 1:5000 which is produced and periodically updated by 
aerial photogrammetry. 
4.4. Basis of Rural Cadastre 
The orthophotomaps without contours at scales of 
1:5000 and 1:10 000 serve as basis for the rural 
cadastre. For this purpose aerial photographs are taken 
by a wide-angle aerial camera (focal length 15 cm and 
format 23x23 cm) from altitude 2.4 or 4.5 km above the 
terrain where aerial photographs are obtained at 
approximate scale of 1:16 000 or 1:30 000 respectively. 
The orthophotoscopy is accomplished by the systems 
Zeiss Topocart-Orthophot and Topomat. The necessary 
control points for absolute orientation of stereomodels 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B6. Vienna 1996 
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