Map preparation method and process

Section 1 Methodology and Process of Map Preparation

1. Different methods of map compilation <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br> To sum up, there are mainly the following methods of drawing.

1.1 Field mapping and photogrammetric mapping is a method of using the general ground measuring instruments or aerial photography and ground stereo photogrammetry instruments to measure the map. This method can be used to measure large-scale topographic maps, water conservancy maps, engineering plans, city plans, etc., and the measured maps are detailed and accurate, with high geometric accuracy. Currently, global positioning system positioning and digital mapping technologies have been widely used, including ground total station digital mapping and aeronautical and satellite digital photogrammetry techniques to measure cadastral maps and topographic maps. Among them, aerial and satellite photogrammetric maps must have 40 to 60% of the image overlap. At the same time, ground and aerial and satellite photogrammetry cartography must have a certain number of geodetic and level control points in order to carry out various corrections according to control points and finally pass An optical three-dimensional terrain model or a digital three-dimensional model is established, and a large- and medium-scale topographic map measurement system is completed by a stereo measurement and a digital analysis and mapping apparatus.

1.2 Field Survey Mapping is to conduct field observations, investigations and investigations in the field, conduct observations and analysis, and fill in the professional content and outline contours on the existing topographic maps. So this method is also called field mapping. In the field investigation and investigation, some specimens (such as rocks, plants, soil, etc.) need to be collected for indoor qualitative and quantitative analysis, which helps to correctly classify the types. On the basis of mapping in the field, the interior will be further extrapolated by geographic extension, and the professional content and outline boundaries of the entire region will be drawn. This is the main method for compiling large- and medium-scale geological maps, landforms, soils, vegetation, land use and other thematic maps.

1.3 Data data mapping is the use of various observation record data (including fixed or semi-stationary stations, indefinite station, aviation or remote observation observations), statistical data (including population census, economic statistics), after analysis and calculation, Compiled into various maps.
This is the main method for compiling geomagnetic, seismic, meteorological and climatic, hydrological, marine, environmental pollution, and various demographic and economic statistical maps. The meteorological and hydrological element stations have accumulated relatively long-term observation data, and such elements are generally cyclical and have a certain degree of change. Therefore, it is necessary to take multi-year averages, and sometimes to supplement semi-local observation data. The data data mapping needs to select indicators and patterns that reflect the quantitative characteristics of the mapping objects according to the level of detail of the data content and the purpose of the map, and then reasonably select the quantitative grading and gradient ruler to perform calculation processing and map compilation.

1.4 Map Data Mapping refers to the method of using map data to compile maps. It is one of the main methods for the preparation of small and medium-scale maps, including:
(1) Using the medium-to-large scale map data to draw down similar small and medium scale maps. Mainly use large-scale topographic maps to compile medium-scale topographic maps and medium-small scale ordinary maps; use medium and large scale thematic maps to compile small and medium scale thematic maps.
(2) The use of topographic maps or other maps to calculate the data, the preparation of the form of quantitative maps, such as the ground slope map, the map of the degree of cutting landscape, water density maps.
(3) Use single factor analysis maps to compile comprehensive maps, compose maps, or use maps of different periods to compile dynamic changes (changes) maps.

1.5. Text data mapping is a method of compiling maps using literature data (including historical data, archaeological data, local records, etc.). For example, historical earthquake records are compiled using historical earthquake records (arranged according to local records). Historical maps, population distribution maps in historical periods, and animal distribution maps in historical periods are compiled using archaeological and historical documents.

1.6 Remote Sensing Data Mapping is the use of aerial and satellite imagery to map. Generally, it uses black and white, multi-wave spectrum, multi-frequency radar, infrared and other aviation or satellite images. Based on indoor analysis and interpretation, it is field-proven and uses the established image interpretation (interpretation) markers to compile various thematic maps. At present, it is also possible to improve the ability of image analysis and interpretation and the accuracy of content rendering by means of image false color synthesis, image enhancement and density segmentation and other optical instrument processing and optical three-dimensional rotation. The use of computers and image processing equipment, the use of digital images for automatic classification through unsupervised classification, supervised classification or other image analysis models, and matching with topographic maps or geographical base maps have become the main methods for compiling various thematic maps.

1.7 Computer graphics is a method of automatically compiling maps using computers and certain input/output devices. Generally through the three basic processes of data input, computer processing, and graphic output. According to the form of input data, it can be divided into map data, data data and image data.
The data data can be directly input into the computer, and the graphics and images must first be converted by numbers. The map product is generally output through a screen display, a plotter, a color inkjet plotter, and a color electrostatic plotter. Computer graphics can greatly increase the speed of drawing and expand the scope of drawing. It is the main drawing method in the information age.
Currently these seven mapping methods are often used in combination. For example, the combination of field survey mapping and remote sensing mapping, the combination of data mapping and computer graphics, the combination of map data mapping and computer graphics, and the combination of remote sensing mapping and computer graphics. In short, remote sensing mapping and computer graphics have become the most important method of drawing today.

2. Division of map preparation process and phases <br> Regardless of which drafting method, the general process of map compilation usually includes map design and editing preparation phase, map preparation and compilation phase, and map finishing phase. , map printing stage (Figure 7.1). Although computer map mapping has been widely used, the computer mapping process is very different from conventional conventional map compilation. Map editing and map finishing are combined into one, and the map making process is also greatly simplified. In particular, the map electronic publishing system makes map design, compilation and plate making more integrated. This aspect will be specifically described in the chapter "Computer Graphics and Map Publishing System." However, it is still necessary to understand the general map preparation process. Because part of the preparation process and methods of conventional maps are still applicable to computer graphics, at the same time, the problems existing in traditional and conventional drafting method technologies and the development process of cartographic method technologies are also helpful in further improving the level of computer graphics. Therefore, this chapter still describes the general map making process and methods in more detail.

2.1 The map preparation and editing preparation stage mainly completes the preparations before the map design and the formal compilation of the map. Generally include the selection of topics, contents, indicators, and map scales and map projections of the map according to the purpose and use of the map; collecting and analyzing the map data; understanding the characteristics and distribution rules of the familiar drawing area or drawing object; selecting the expression method and Develop symbol legends; determine the principle requirements for drawing synthesis and the drawing process. For thematic maps, the requirements for the compilation of base maps and the principles for classification and grading of thematic content should also be proposed and the drafting method should be determined. Finally, a map preparation design document—drawing outline or map preparation design book—is written, and a specific work plan for completing the map preparation is formulated.

2.2 The preparation and drafting of maps mainly completes the drafting and editing of maps. It usually includes data processing, drawing and drawing mathematics, and re-drawing and compiling map contents. In the compilation process, a map summary (cartographic synthesis) is required, that is, the selection and generalization of map contents. Of course, in the editing preparation stage, the classification, classification, and illustration of the map also include a certain map summary, but the mapping section of the map compilation outline is always implemented. Map compilation is a creative work. The final result of the compilation phase is the compilation of the original map. The so-called drafting of the original map is done according to the drafting outline or drafting specification. The maps are in compliance with the final draft requirements in terms of map contents and accuracy. For thematic maps, the original artwork (author's draft) is usually compiled by professional staff before the map is officially edited and edited by the drafting staff to complete the formal drafting of the original image.

2.3 The map finishing stage is mainly based on the map printing requirements to complete the preparations before printing. Including line drawing, symbol drawing (or engraving), and clipping note according to the requirements of the printing plate making, and completing the line drawing and annotation version of the original printing (original drawing). At the same time making color samples and color separation reference maps.

2.4 The map printing and printing stage mainly completed map printing. Including the original copy of the original photo or reprint, sub-coating, plate proofing, on-machine offset printing, binding and so on.

At present, the computer graphics and automatic platemaking integration system (computer map publishing production system) has reduced map editing, editing, finishing, and platemaking to a stage, namely, computer design, editing, and automatic color separation, output film, and direct plate making. Printing on the machine.