Glossary
1 , Map: according to certain rules of mathematics and general principles of the unique system of symbols and mapping the natural and socio-economic phenomenon of the earth's surface reduced representation across the plane, which reflects the mapping of the spatial distribution of the phenomenon, the combination of contacts and in changes and developments in terms of time and space.
2 , map projection: follow a mathematical law, the graticule earth ellipsoid onto a respective projection plane.
3 vectoring: vectorization means for converting vector data into raster data process.
4 , layers: a user or according to certain criteria need to certain related objects together, we call layers. As a geographic map configured in the aqueous layer, a layer constituting the rail and the like.
5 , histograms: a different chart statistics. The range of measured values is divided into several partitions, to a bottom section, the number of measurements in each segment is high, a plurality of rectangular configuration, the configuration of FIG these rectangles are called histogram.
- Metadata: geographic datasets used to describe the content, quality, representation, spatial reference, management and other features of the data set, it is one of the core standard implementation of geospatial information sharing.
- Of GIS: establishing the geographical coordinates of the point of the earth ellipsoid (λ, φ) plane corresponding to the functional relationship between the coordinate point (x, y) on a plane:
- Map projection: management and analysis of spatial data application engineering, but also across the earth science, information science and applied basic space science disciplines. The technical system consists of computer hardware, software, and related methods consisting of processes to support spatial data collection, management, processing, analysis, modeling and display, in order to solve complex planning and management problems.
- Quadtree coding: is the most effective one raster data compression coding method. The basic idea is to first put a raster image or a map divided into four parts and the like, to check if a promoter region genitive network contain the same value (or gradation property value), then the sub-region is not subdivision down; otherwise, then this area is divided into four sub-regions, and recursively divided until each sub-block contains only up to the same gray value or attribute.
- Data processing: the input data QA and correction, graphic data inputted finishing process
The vector map MAPGIS divided into three categories according to the basic elements of geometric features: point data, line data and area data (i.e., data plane). Correspondingly files into three basic categories: point file (* .WT) Line files (* .WL) and zone files (* .WP).
Point file: the map data point is the midpoint of the substance referred to, symbols or comments is determined by the position of a control point. It is not a simple point, but includes various comments (English, Chinese characters, numbers, etc.) and special symbols (including circles, arcs, lines, and other five-pointed star symbol). All point primitive data is stored in the point file (* .WT) in.
Line item: map middle line is the substance collectively. Various MAPGIS linear (e.g. dot chain line, provincial boundaries, boundaries, contour lines, roads, embankments) in units of lines as the edit line primitives. All data is stored line primitives online file (* .WL) in
Area File: often said surface region, which is connected end to end by the arc composed of a closed figure, and the color and patterns to fill a closed region pattern is formed. Such as lakes, residential areas and so on. All zones primitive data is stored in the zone file (* .WP) in.
Project: a project requires a lot of file editing, processing and analysis. Engineering is a description of these files and manage information content of these documents MAPGIS file type, which contains all the files in a project.
Map: according to certain rules of mathematics and general principles of the unique system of symbols and mapping the natural and socio-economic phenomenon of the earth's surface reduced representation across the plane, which reflects the mapping of the spatial distribution of the phenomenon, the combination of contacts and in terms of time and space changes and developments.
Window: a rectangular region of the user coordinate system.
(1) layers: a user or according to certain criteria need to combine some of the geographical entity, called layers.
(2) control points: the position refers to the planar surface elevation and the known point, it is possible to control the graphics processing shape pattern, reflecting the pattern position.
(3) dot elements: Element point is referred to as point features, sometimes referred to as points, so-called dot pattern element is a means to determine its position by the control point has a determined shape. It includes several types of characters, strings, sub-picture, circles, arcs, line segments and the like.
(4) arc: arc includes a series of rules, a sequence of set points, which may be formed with a contour area. It is a curve with two different concepts, the former belongs to the bin, which belongs to the line element.
(5) region / area; region / area is closed figures arcs connected end to end, or from the same direction thereof.
(6) TOPOLOGY: Accession correlation coefficient, refers to a mathematical method be structured spatial relationship primitives points, lines, and other areas. Including: Rank adjacent contact resistance and arcs area definition region.
(7) digital: digital means for converting the graphics, text and other computer recognizes the analog information becomes, handling, storage of digital information process.
(8) vectorization: vectorization means for converting vector data into raster data process.
(9) rasterizing: rasterizing means for converting vector data into raster data process.
(10) the node: a node is the end point of the arc, or the number of intersections between the arcs.
(11) adjustment node (vertex matching): originally the same node, since the digital error, or several arcs not closed at the anastomotic junction intersections i.e., leaving a gap, for this purpose they are at the intersection endpoint according to certain matching radius kneaded together, the process of becoming a real node, called nodes adjustment.
(12) TIN: is established by a set of irregularly spaced points having X, Y and Z coordinate values of the adjacent triangles disjoint, including nodes, lines and triangular faces, is used to describe the surface of the facet region.
(13) a digital elevation model (DEM): the digital terrain model terrain elevation property is referred to as digital elevation model.
(14) Digital Terrain Model (DTM): is a digital representation of the terrain surface morphology attribute information, is described with the spatial position of the digital terrain features and characteristics of attributes. It consists of a series of ground points X, Y position and Z is the elevation associated components.
Projection: establishing point is (Q, λ) of the process of the functional relationship between the points (x, y) on different planes and the earth's surface;
Projection transformation: is the process different map projections functional relationship transformation;
Gauss Projection: tangential and the horizontal axis is an isometric projection elliptical cylinder, by the German mathematician Gauss, and after expansion by the formula for calculating Kruger, so called Gauss - Krüger, referred Gauss projection. It is assumed that a cylinder with an elliptical cross-earth ellipsoid decent a certain meridian, latitude and longitude lines at equal angular conditions within the central meridian east and west each 3 ° or 1.5 ° longitude range is projected onto elliptic cylinder, and the elliptic cylinder obtained by flatly developed.