Map Compilation Procedures

the operations involved in preparing the compilation and printing originals of maps. Map compilation procedures include editorial and preparatory work, compilation, and the preparation of map originals for publication (map design).

Editorial and preparatory work includes collecting, systematizing, studying, and scientifically collating cartographic source material. Depending on the purpose and nature of the map, a map montage model is made, and the scale, cartographic projection, and cartographic methods of representation and symbols are chosen. The decisions on these questions, together with the technical instructions for the method to be followed in compiling, preparing for publication, and publishing the map, are described in an editing plan, or map program. The editing plan is supplemented either by a series of graphic charts and a section with the color pattern or by the author’s model. Editorial and preparatory work concludes with the computation of the cartographic projection, the construction of geographic and coordinate grids, and the entering of geodetic control points, indications of areas adjoining the map margin, the marginal representation, and the basic cartographic material.

Compilation consists in transferring the cartographic data from the source materials to a prepared base in order to make a compilation original.

The basic process in map compilation is known as cartographic generalization—the selection and simplification of the material that is to be mapped. The data are transferred from the source material to the compilation original by photoreproduction, by photo conversion, by projection through an epidiascope or optical drawing instruments, by photoelectronic conversion, or by mechanical writing methods, such as using the pantograph and perspectograph or graphic procedures (compilation by use of a grid). These methods may be combined. The topographic elements to be shown on the map are entered on the compilation original in a sequence. First, the control points and ground features serving as landmarks are entered, followed by hydro-graphic objects, population centers, road network, relief, vegetation, soils, and boundaries. The specialized data of thematic maps are compiled on a separate copy. Geographic names are entered immediately after depicting the items to which they refer. When nonstandard maps are being compiled, the compilation original is supplemented with a copy of the map’s color pattern indicating the colors that are to be used in printing all tone elements of the map, such as the hypsometric coloring, the colors of bodies of water and vegetation, and special data.

The finished compilation original of a map sheet is edited and corrected. Since it is an author’s original, its graphic qualities do not meet map printing standards and it must be prepared for publication. The publishing original is prepared either by drawing on a paper or plastic base or by scribing on specially coated plastic. An outline obtained from the compilation original is used.

The drawing is done in strict conformity with standard symbols. The drawing may be composite (all hachures entered on one copy), partially separated (one element of the map drawn on one copy and the rest on a second copy), or completely separate (individual publishing originals prepared for each hachure element). Only separate publishing originals are prepared when drawing on plastic.

The lettering is prepared by photocomposition and is usually glued directly onto the drawn originals (contour, hydrography, relief); sometimes the lettering is a separate publishing original. When map originals are being prepared for publication by scribing on plastic, separate engravings are made for each hachure element of the map. The work is done with special scribing tools. From negative engravings, diapositives are obtained onto which the typeset lettering is glued. When publication originals are being prepared either by drawing or by scribing on plastic, special masks of transparent plastic are usually made for the color pattern of the map. The work is checked visually and by preparing a line original on paper or plastic. When composite or partially separate drawings on paper are used, the process of preparing map originals for publication concludes with making separate scanning models and color (lithographic) models. The former serve as guides during retouching, and the latter are used to make the printing plates for the maps’ color pattern.

In analyzing the current trends toward improving map production a number of basic directions may be identified: the development of techniques for compiling and preparing maps for publication; mechanization of photocomposition; introduction of microfilming, electrophotography, and photoluminescence; improvement of photocopying operations; automation of computing and constructing the mathematical base of the map with computers and the automatic coordinatograph; and automation of the preparation of publishing originals and the process of generalization.