Aerial surveying and photogrammetry are the prin- 
cipal methods of topographical study of the territory of 
our country. The topographical I s 100 OO0 maps compiled 
from aerial photographs are used for development of all 
branches of our national economy. At present,most atten- 
tion is being paid to large-scale mapping of regions of 
industrial construction and intensive agriculture. This 
problem is being solved under utilization of aerial 
survey methods and modern photogrammetric equipment 
produced by home industry. 
Of great importance for mapping the country has been 
the differential method of stereotopographic surveying 
developed by Soviet photogrammetrists together with spe- 
cial equipment satisfying the requirements of the said 
method ( aerial cameras provided with lenses designed by 
prof. M.M.Rusinov;the topographical stereomreter by prof. 
F.V.Drobyshev, and later on - the stereoprojector by 
prof. G.V.Romanovsky and the stereograph by prof. F.V. 
Drobyshev). A new progress in making topographical maps 
of the country with the help of the etereotopographical 
method was achieved with introduction of photographic 
office interpretation and visual identification from 
helycopters. | 
On prof. A.N.Lobanov's initiative, an analytical me- 
thod of spatial phototriangulation with precision stereo- 
comparators and electronic computers has been developed 
and put into practice, which method has contributed to 
raising efficiency and accuracy of plotting of photo- 
graphs. A radiogeodetic method of determination of coor- 
dinates of the projection centres, the gyrostabilized 
mounting, radioaltimeter, and other modern facilities of 
home production have found wide application in aerial 
surveying. 
All topographical maps of the USSR compiled by ste- 
reotopographic methods must satisfy the unified specifi- 
cations that are obligatory for all mapping organizations 
and departments; in this way high quality of produced