Each such sign consists of a contour, i.e. a planned outline of the represented object and the filling explanatory designation in the form of background coloring, color shading or a grid of the badges, identical on the drawing specifying a sort, a kind of object.
Extra large-scale or dot conventional signs represent the small-sized objects (wells, constructions of tower type, separate trees, etc.) which are not expressed on the scale of the card and therefore they can be presented on it only in the form points.
Cumulative reading conventional signs: conventional signs of the studied objects should be considered it is not isolated, and in an interconnection with the image of a relief, etc. district elements, determining by that joint influence of all these objects on performance of a task in relation to which the district is studied.
The reduced signatures accompanying some conventional signs explain properties of the represented objects, reporting about them data, it is impossible to display graphically. So at conventional signs of the industrial enterprises and some objects they specify a sort of object or production. For example,. - engineering plant, - a, etc.
To declare inquiry and to tell that in order that it is full and correct to use cards as measuring documents, it is necessary to understand well their geometrical essence and the mathematical principles of their construction.
Topographic maps of foreign countries. Topographic maps of various states are not identical on projections and scales, and also according to the contents and registration. However the principle of creation of the cartographical drawing of the district and a graphic representation of a and its elements are similar and therefore language at topographic maps to a certain extent can be considered international. However it is necessary to consider that scales of foreign cards can be formed in inches, miles, etc. The land relief on the majority of topographic maps of the foreign states is represented also as well as at us. Almost all states apply the same colors to registration of cards as well as at us. The considerable difficulty can cause only inscriptions in foreign languages.
Linear subjects like roads, streams, etc. which have only length in scale also belong to extra large-scale signs, and the cannot be represented in scale. The provision of such objects on the district corresponds to a longitudinal axis of a sign on the card.
Color registration of cards. Cards for the best readability in paints. Thanks to it the image of the district as if on separate elements, each of which is distinctly allocated in the color.
The geographical position of points on a terrestrial surface is defined, as we know, by their coordinates. Therefore the mathematical of creation of the cartographical image consists in designing and representing a spherical surface of Earth on a (card), strictly observing thus unambiguous compliance between coordinates of points on a terrestrial surface and coordinates of their image on the card.
Explanatory inscriptions and digital designations. On cards the full and reduced signatures are applied. Completely names of settlements, rivers, mountains, and certain natural boundaries are signed. Fonts of signatures of names of settlements and rivers at the same time serve also as a symbol as they supplement with the sizes and a tracing the characteristic of these objects.
Each leaf of the card has the nomenclature and for more convenient selection of the card from several sheets to have one leaf of the card enough and to determine the others by it. For this purpose on each leaf of the card on a frame from 4 parties the nomenclature of the next leaf is signed.
Thanks to the geographical grid which is been the basis for division of the card into sheets location on the globe of any site of the district represented on this leaf of the card is defined. Besides coincidence of the parties of a frame to meridians and parallels defines their arrangement in relation to the parties of the horizon; the top party of a leaf of the card - the North, lower – the South, other parties of the horizon. (shows on sheets of the card).