| GLOSSARY | |
| BANCHE SIT DATABASES | Databases that collect, treat and represent territorial or "geographic" data in the strict sense, that is those characterized by the simultaneous presence and the mutual link of a "geographic component" (one or more pairs of geographic coordinates) that allows to describe them and locate them in the space geographical and a possible "descriptive component". |
| MAP GEOGRAPHICAL | A geographical map is a graphical representation of geographical elements or other spatial phenomena (lakes, rivers, roads, cities ...) which provides two types of information about the area represented:
the position and the aspect. The position allows us to understand where a particular geographical element is on the surface of the earth and what its relations are with the other elements. The aspect shows us both the qualitative characteristics (name, type ..) and the quantitative ones (area, length ...) of the element represented. Each map in addition to spatial and descriptive information, it presents some features techniques that define it and determine its use. These features include the scale, accuracy, the projection system, the coordinate system. |
| DIGITAL CARTOGRAPHY | In the digital version of a traditional map, the position and description
of the elements are stored in a series of computer files. To identify
the position of the geographical elements, a system of
Cartesian coordinates x, y or x, y, z is used: each point is represented with a single pair of x, y coordinates;
each line is stored as an ordered series of x, y coordinates; each area is stored as an ordered series of coordinates x, y which define the perimeter segments of the closed figure. With the coordinates x, y it is possible to represent points, lines and polygons as coordinate lists, rather than as a drawing. In most cases, the storage of geographical elements uses real-world coordinates: these coordinates they represent a real location on the surface of the earth, in one of the many coordinate systems. The relationships between geographical elements are expressed, on a digital map, with the use of topology. The characteristics of the geographical elements are stored in the computer in a file, generally called a table, as a set of numbers and characters. |
| CARTOGRAPHY BASIC | It is the set of cards that relate to a certain territory, built with topographic and photogrammetric techniques, which represent the plans (waterways, roads, railways, bridges, houses, etc.) and the altimetry composed of listed points or level curves. |
| CLIENT | The term client indicates the program used by the user to connect to the mapservices available on the Intranet server. |
| LEVEL CURVE | It is the set of lines at a constant altitude that describe the planimetric course of the ground, generally obtained by manual interpolation or automatically starting from a TIN, DEM or DTM. |
| DATABASE | By database (database, database or archive) we mean a set of information of different types. These data are organized according to precise criteria that allow a quick consultation. |
| SPACE DATA | Geometric data characterized by a geographical reference. |
| DEM (Digital Elevation Model) | It is a raster data model that represents the elevation of the terrain. It can be generated from quoted plans or contour lines and is generally used to conduct visibility analysis, generate longitudinal profiles, perform slope and exposure analyzes, cliviometries, etc. |
| DIGITAL | A digital data is information that can be expressed by whole numbers that can be stored in a magnetic medium. |
| DTM (Digital Terrain Model) | Literally digital model of the terrain, raster or vector, see DEM and TIN. |
| GAUSS-BOAGA | It is a coordinate system in inverse cylindrical projection typically used for cartography of the territory in Italy (IGMI, Catasto, Regional Technical Maps, etc.). |
| GEOTAG | Software procedure which consists in positioning, by means of points with known coordinates (control points), vector data or a raster image in the respective area of the real territory according to a given reference system. |
| GIS (Geographical Information System) | A complex set of hardware, software, human and intellectual components to acquire, process, analyze, store and return in graphical and alphanumeric form data referring to a territory. |
| GPS (Global Positioning System) | It is a system that allows, by means of a receiver, a dedicated software and a constellation of satellites, to determine the position on the ground and the altitude of a point, with an accuracy that varies from a few millimeters to a few meters depending on the type of equipment and relevant operating procedures. |
| GRAFO | It is an interconnected set of arcs which in a GIS generally describes a network (road, hydrographic, technological, etc.). GIS softwares generally have functions of analysis and modeling of networks based on a graph (optimal path, optimization of stops, localization analysis, etc.). |
| GRID | It is the name of the ESRI ARC / INFO extension that processes databases in raster format and is also used to define the corresponding data format. |
| RASTER | Any image can be thought of as consisting of a set of small equal areas (pixels), arranged according to lines and columns, such as to constitute a matrix. The values associated with each cell can express both graphic information (color, gray tone, etc.) and descriptive information (temperature, slope, etc.). |
| INTRANET | INTRANET it is a reduction of the Internet, applied to a business field. It is an "internal" network, which allows it to be used only by a certain number of selected users. To understand, we can call Intranet any Internet network not open to the general public, but limited and closed. |
| LAYER | See information layer. legend: it is a tool present on the cards that associates the graphic symbols used to the single themes, to allow their reading. |
| MAPSERVICE | Project present on the Intranet server corresponding to a specific thematic map (Orthophoto, Viability ...). Within this map are inserted various themes having different formats: TIFF images, arcs, polygons. |
| MOSAICKING | It is the set of operations that, within the GIS framework, allows for the merging of multiple maps in digital format to achieve territorial continuity. |
| ORTOFOTOGRAFIA | Technique for the production of orthophotocards that uses tools and procedures capable of providing a metric representation of the terrain in the form of photographic images. |
| OVERLAY | Spatial analysis procedure that allows information layers (layers) to be superimposed and intersected, thus combining the information associated with each of them to produce a new synthesis layer. |
| PIXEL | Contraction of picture element, it is the elementary component of a raster image characterized by an associated value. |
| PLUG-IN | Plug-ins are software programs that "plug in" to a main program, implementing additional specific functions. |
| POLYGON | A closed area bordered by arches. |
| METRIC PRECISION | It is a local quality parameter of a cartography, defined as the difference of the position of a point on the cartography with respect to its real position in the national cartographic reference system. |
| GEOGRAPHIC PROJECTION | It is a global projection system, used historically first, based on the subdivision of the earth into meridians and parallels. Its reference system, latitude / longitude, measures the angular distances starting respectively from the reference plane of the equator and from that of the Greenwich meridian. |
| POINT | Geometric element used to define the position of elements that are point-like in the acquisition scale, defined by a pair of coordinates (x, y) and possibly a dimension (z). |
| QUERY | Set of SQL statements that allow you to extract geographical and alphanumeric information from the database. |
| RASTERIZATION | Operation that automatically allows to obtain a raster image from vector data or paper documents (scanner). |
| RECORD | Group of contiguous positions (fields) of information, even inhomogeneous, which can be accessed in different ways. |
| AEROPHOTOGRAMMETRIC RETURN | Process that allows, using special instrumentation (analog or digital photo editor), to build a cartography (both on paper and digital) of a portion of land from stereoscopic aerial photos. |
| RESOLUTION | It is a local quality parameter of a cartography and corresponds to the dimensions of the smallest detail represented in the vectorial cartography and to the length of the side of the cell (pixel) in the raster format. |
| NOMINAL SCALE | It is a parameter that defines the reference scale of a numerical cartography according to the corresponding scale of a traditional cartography realized following the same metric precision requirements. |
| SCALE | The scale of a geographical map indicates, in practice, how many times a portion of the earth's surface has been reduced to be represented on a sheet of paper. It is generally expressed as the ratio between a distance on the map and the corresponding distance on the ground. The scale ratio used for a map determines the information content and the size of the area that can reasonably be represented. Large-scale cards (1: 500, 1: 1000, 1: 2000) are defined, on a medium scale (1: 5000, 1: 10000) and on a small scale (from 1: 25000 onwards). |
| SERVER | The term "server" may refer to the physical computer, network operating system (eg Windows 2000 Server) or applications running on a network operating system. |
| SERVIZI WMS - Web Map Service | The term indicates a specific technique defined by the OGC. Through this specification, spatially referenced data maps are reproduced starting from geographic information. The WMS service can be called by GIS clients (Open Source or Commercial) by inserting a simple URL, thus allowing to load the data present in the chosen service. |
| PROJECTION SYSTEM | They are systems that allow us to represent the almost spherical surface of the Earth on a plane while maintaining certain conformances (isogony, equivalence, equidistance, etc.): the best known are the Geographical, the UTM, the GAUSSBOAGA, the LAMBERT, others are the Conica , the Polar, the Stereographic, the Cylindrical and the Planar also variously combined. |
| REFERENCE SYSTEM | Each projection has its own reference system, from which we start to calculate distances. For example, the Geographical Projection has as its references the intersection between the Greenwich meridian and the Equator, the UTM foresees predetermined segments of six degrees called fusi, which are in turn divided into zones (Italy is straddling spindles 32, 33 and 34), the all-Italian GAUSS-BOAGA, parteda Monte Mario (in Rome) and uses conventionally measured kilometers from 1500 to the left and from 2520 to the right of the reference meridian. |
| INFORMATIVE SYSTEM | Set of equipment, procedures and people who have the task of collecting, organizing, selecting, storing and communicating data concerning the activity of an organization. Its goal is to make available to operational decision makers all the information necessary to make the best possible choices. |
| TABLE OF ATTRIBUTES | Tables are an integral part of the information layer. Each table is related to a homogeneous group of geographical elements of the map (roads, rivers, contour lines, etc.) and consists of a variable number of rows and columns. Each line (record) contains the description of a single element geographic and each column (field or attribute) stores a specific type of information. The characteristics of the geographical elements are generally translated into numerical or alphabetical codes, before being inserted in the relative table. |
| THEMATISM | Representation of a raster or vector map in which points, lines or surfaces are associated with symbols, screens or colors that represent the result of a quality analysis (land use, zoning, traffic intensity on a road, etc.) .). |
| TIFF | It is a standard format for the interchange of raster data. |
| TOOLBAR | Panel present in the HTML viewer, including several buttons corresponding to various functions to move, query and print the contents of the mapservice. |
| UTM | It is an inverse cylindrical projection adopted worldwide. |
| VECTOR | It is a graphical data storage system according to which objects are stored based on the Cartesian coordinates of the points and lines that compose them. |
| VECTORIZATION | Operation that allows in automatic or semiautomatic way (that is with the assistance of an operator) to obtain a set of vectors starting from a raster image. |
| VIEWER HTML | Visualization program of the various mapservices. |
| ZOOM | Video enlargement or reduction function (in, out) present among the potentialities of most graphic software. |