V. SUKHOV
TECHNIQUE AND METHODS OF SOVIET CARTOGRAPHY
Soviet cartographic factories use a variety of methods to compile and produce maps
depending on their content, availability of equipment and accepted technology. In a
short article it is impossible to discuss every aspect of map making, and so I shall con-
fine myself to the technical aspects of mapping.
In its making a map goes through the following stages:
a) construction of the cartographic grid on the original;
b) transfer of the model from the cartographic material to the original; and c)
generalisation.
Before delineating the cartographic grid on the original, a calculation is made of the
common points, namely, the points of intersection of the parallels and the meridians,
the grid lines, junctions and the Vertexes of the grade frames.
In constructing the cartographic grid, point transformation may be determined by
analytical formulas, in particular by two equations of the cartographic projection:
x E(Q,a); y f2(Q,a)(1)
expressing the functional relation of the surface of a spheroid and the rectangular co-
ordinates of a plane. In this case, the co-ordinates of the surface are latitude Q and
longitude a, while the co-ordinates of the plane (i.e. the map) are absciss x and Ordi
nate y; with f-L and f2 being continuous and finite within the limits of a defined area.
There are several dozen projections differing in deformation and geometrical properties,
such as: a) equiangular transverse cylindrical projection for topographic maps; b) Mer-
cator's projection for marine navigation charts; c) Kavraisky's linear equidistant conical
projections for most small-scale maps of the Soviet Union, etc. The uniform System of
co-ordinates established in 1942 is used for all maps of the country's territory. The
initial data for this system are as follows:
Krasovsky's ellipsoid with semi-major axis
a 6,378,245 m, and a flattening of 1/298.3;
At Pulkovo the height of the geoid over the ellipsoid is zerothe geodetic co-ordinates
of Pulkovo Observatory (centre of signal "A") are
latitude 59°46' 15.359"
longitude 30°19' 28.318".
In Order to facilitate calculations, special tables of co-ordinates have been compiled
for many projections. In compiling topographical maps use is made of special tables
of co-ordinates by Gauss-Krüger for Krasovsky's ellipsoid. There are tables for com
piling marine navigation charts and many small-scale maps, such as the tables of the
Central Research Institute of Geodesy, Aerial Photography and Cartography. Thus, the
calculation of co-ordinates is highly simplified and consists of picking up the corres-
ponding values of the co-ordinates from the tables.
The c o-o rdinatograph
These data are used to construct the cartographic grid on the original with the aid
of a co-ordinatograph. Electric co-ordinatographs are widely used in cartographic pro-
duction. Their main principle is motion in two strictly perpendicular directions with
the aid of high precision screws, in place of the gear racks used in the old designs.
The register and the flywheels which set the screws in motion are mounted in the
driver unit, which also houses the electrical device for the marking (setting) of points
