Geoinformation technologies, the main characteristics of modern GIS. Geoinformation systems and technologies Geoinformation technologies in brief

Geoinformation systems and technology

Geographic Information System (GIS) is a multifunctional information system designed for collection, processing, modeling and analysis of spatial data, their display and use in solving computational problems, preparing and making decisions. The main purpose of GIS is to form knowledge about the Earth, individual territories, terrain, as well as to bring the necessary and sufficient spatial data to users in a timely manner in order to achieve the greatest efficiency of their work.

Geoinformation Technologies (GIT) are information technologies for processing geographically organized information.
The main feature of a GIS, which determines its advantages in comparison with other AIS, is the presence of a geoinformation basis, i.e. digital maps (CC) that provide the necessary information about the earth's surface. At the same time, the Central Committee must ensure:
accurate binding, systematization, selection and integration of all incoming and stored information (single address space);
complexity and clarity of information for decision-making;
the possibility of dynamic modeling of processes and phenomena;
the possibility of automated solution of problems related to the analysis of the characteristics of the territory;
the ability to quickly analyze the situation in emergency cases.
The history of the development of GIT goes back to the work of R. Tomleson on the creation of the Canadian GIS (CGIS), carried out in 1963-1971.
In a broad sense, GIT is data sets and analytical tools for working with coordinated information. GIT is not information technology in geography, but information technology for processing geographically organized information.
The essence of GIT is manifested in its ability to associate with cartographic (graphic) objects some descriptive (attributive) information (primarily alphanumeric and other graphic, sound and video information). As a rule, alphanumeric information is organized in the form of relational database tables. In the simplest case, each graphical object (and usually point, line and area objects are distinguished) is assigned a table row - an entry in the database. The use of such a connection, in fact, opens up such rich functionality for the GIT. These capabilities vary from system to system, of course, but there is a basic set of functionality that is typically found in any GIT implementation, such as the ability to answer "what is this?" questions. indicating the object on the map and "where is it?" selection on the map of objects selected by some condition in the database. The basic can also include the answer to the question "what's next?" and its various modifications. Historically the first and most universal use GIT is information retrieval, help systems.
Thus, GIT can be considered as a kind of extension of database technology for coordinated information. But even in this sense, it is new way integration and structuring of information. This is due to the fact that in the real world most of the information relates to objects for which their spatial position, shape and relative position play an important role, and therefore, GIT in many applications significantly expand the capabilities of conventional DBMS, since GIT is more convenient and intuitive to use. and provide the DL with their "cartographic interface" for organizing a query to the database, along with the means of generating a "graphical" report. And finally, GIT adds a completely new functionality to conventional DBMSs - the use of spatial relationships between objects.
GIT allows you to perform operations on sets of cartographic objects similar to ordinary relational ones (JOIN, UNION, INTERSECTION). Operations of this group are called overlays, since they use in different versions the spatial imposition of one set of objects on another. In fact, overlay operations have a great analytical potential, and for many areas of application of GIT are the main ones, providing the solution of applied problems (land use, integrated assessment of territories, and others).
GIT offers an entirely new path for the development of cartography. First of all, the main disadvantages are overcome ordinary cards: static data and limited capacity of "paper" as a carrier of information. In recent decades, not only complex specialized maps such as ecological maps, but also a number of ordinary paper maps have become "unreadable" due to information overload. GIT solves this problem by managing the rendering of information. It becomes possible to display on the screen or on a hard copy only those objects or their sets that the user needs at the moment. That is, in fact, a transition is being made from complex complex maps to a series of interconnected private maps. At the same time, better structured information is provided, which allows it to be used effectively (manipulation, data analysis, etc.). Obviously, there is a tendency for the role of HIT to increase in the process of activation information resources, because huge arrays of cartographic information can be effectively converted into an active machine-readable form only with the help of GIT. Also, in GIT, the map becomes a truly dynamic object.

The latter is due to the following new features of the GIT:
scalability;
transformation of map projections:
by varying the object composition of the map;
"interrogation" through the map in real time of numerous databases containing changeable information;
by varying the symbology, that is, the way objects are displayed (color, line type, etc.), including the definition of symbology through the values of the objects' attributes, which allows you to synchronize the visualization with changes in the database.
It is now widely understood that GIT is not a class or type software systems, but the basic technology (umbrella technology) for many computer applications (methods and programs) that work with spatial information.
Since DCMs are data sets of a complex structure, it is advisable to present them in various formats. The DCM format is understood as a specially introduced system of classification and coding of terrain data. The efficiency of solving functional tasks (FL) in military control systems largely depends on the adopted format of the CCM. So, for example, in the case of representing the terrain with contour lines, the calculation of the terrain profile takes thousands of times more time than when representing the terrain in the form of a matrix of heights.
One of the most important and most common types of information need for geoinformation is the construction of an image of a map section on the AWP screen (map visualization). But the means of displaying the MSC on the screen of the workstation, along with the above requirements for access means, must also meet a number of specific requirements due to the need for human perception of information. In essence, these are the following ergonomic requirements, which should be considered in conjunction with others:
according to the "readability" of the situation (i.e., to have sufficiently high characteristics of the speed and reliability of a person's perception of information from the operational situation against the background of the map);
according to the "readability" of the map (i.e., to have sufficiently high characteristics of the speed and reliability of the perception of the actual cartographic information by a person);
according to the "comfort" of perception (i.e., the form of data display should not cause excessive stress on a person when perceiving information and irritation of his senses in order to ensure the required duration of maintaining his working capacity).
The federal law requires various data about the terrain for its solution. According to the authors, the whole set of these tasks can be divided into four main classes according to the nature of the use of the CCM:
tasks that require the issuance of a map image to devices I/O automation tools and using it as a background for displaying the operational situation (OCF);
tasks using information about the nature and profiles of the terrain (OHPM);
tasks using road network information (RDS);
tasks that use information about the location of an object within the territory of the state, the zone of responsibility or neutral territory (WMO).
The tasks of the OKF are all tasks that reflect the operational situation on the ground in the process of dialogue with the user. These tasks can display "above the map" information about the groupings of friendly and enemy troops, zones of radioactive, chemical, biological contamination, continuous destruction, fires, floods, directions and lines of action, areas of concentration, etc. is the need to quickly display the map image on the AWS screen at various scales.
The tasks of the OHPM include the tasks of choosing a deployment site for radio relay stations (RRS), tropospheric stations (TRS), radar stations (PJIC), electronic intelligence, electronic warfare, etc. The tasks of assessing the protective properties of the terrain in the areas of deployment of command posts (CP) and communication centers (CS), planning fire impact, etc. also belong to the OHPM class. A feature of the OHPM problems is the need to determine the characteristics of the terrain in the vicinity of a point with arbitrary coordinates at a high speed.
The tasks of the RDS include, in particular, the tasks of determining the route and planning the order of movement of military formations, optimal planning of the transportation of supplies or mail, and some others. These tasks use DSM data on the road network, which must be presented in a special form - in the form of a graph in which all intersecting roads have a common vertex at the intersections.
The MPO tasks use data on state (land and sea) and other borders in the MSC, which are specified in a special form - in the form of closed contours.
According to the type of information needs, many federal laws can be attributed to several different classes at once. In particular, the task of determining the optimal RRS deployment area may have the properties of the OHPM and RDS classes, and in the process of solving for organizing a dialogue with the user, the properties of the OKF class.

In connection with the deep interpenetration of GIS and other information technologies, it is advisable to consider the relationship of GIT with other technologies.

First of all, this graphic technology computer-aided design (CAD), vector graphic editors and, on the other hand, relational DBMS technologies. Most implementations of modern GIT are, at their core, an integration of these two types of information technology. The next type of related information technology is the image processing technology of raster graphic editors. Some GIT implementations are based on a bitmap representation of graphical data. Therefore, many modern general-purpose GIS integrate the capabilities of both vector and raster representation. In turn, a number of image processing technologies designed to work with data from aerial and space surveys are very closely adjacent to GIT, and sometimes partially perform their functions. But usually they are complementary to GIT and have special tools for interacting with them (ERDAS LiveLink to ARC / INFO)

Closely related to GIT are cartographic (geodesic) technologies used in processing data from field geodetic surveys and building maps based on them (when building maps from aerial photographs using photogrammetric techniques and when working with a digital terrain model). Here, too, there is a trend towards integration, as The vast majority of modern GIS include coordinate geometry tools (COGO), which allow you to directly use the data of field geodetic observations, including directly from instruments with digital registration or from satellite receivers. global system positioning (GPS). Photogrammetric packages are usually oriented towards working with GIS and in some cases are included in GIS as modules.

The essence of GIT is manifested in its ability to associate with cartographic (graphic) objects some descriptive (attributive) information (primarily alphanumeric and other graphic, sound and video information). As a rule, alphanumeric information is organized in the form of relational database tables. In the simplest case, each graphical object (point, line or area) is assigned a table row - an entry in the database. Using this connection provides the rich functionality of GIT. These capabilities vary from system to system, of course, but there is a basic set of functionality that is typically found in any GIT implementation, such as the ability to answer "what is this?" questions. indicating the object on the map and "where is it?" selection on the map of objects selected by some condition in the database. The basic can also include the answer to the question "what's next?" and its various modifications. Historically, the first and most universal use of GIT is information retrieval, reference systems.

Thus, GIT can be considered as a kind of extension of database technology for coordinated information. But even in this sense, it represents a new way of integrating and structuring information. This is due to the fact that in the real world most of the information refers to objects for which their spatial position, shape and relative position play an important role. Consequently, GIT in many applications significantly expand the capabilities of conventional DBMS.

GIT, like any other technology, is focused on solving a certain range of tasks. Since the areas of application of GIS are quite wide (military affairs, cartography, geography, urban planning, organization of transport dispatching services, etc.), due to the specifics of the problems solved in each of them, and the features associated with a specific class of tasks being solved and with requirements for input and output data, accuracy, technical means and so on, it is rather problematic to talk about any single GIS technology.

At the same time, any GIT includes a number of operations that can be considered as basic. They differ in specific implementations only in details, for example, the software service for scanning and post-scanning processing, the possibilities of geometric transformation of the original image depending on the initial requirements and the quality of the material, etc.

Since the above model is generalized, it is natural that it either does not contain separate blocks characteristic of any particular technology, or vice versa, it includes those blocks that in some cases may be absent.

Based on the results of the analysis of the generalized model of GIS technology, the following basic GIT operations can be distinguished:

editorial and preparatory work, i.e., collection, analysis and preparation of initial information (cartographic data, aerial photographs, remote sensing data, ground-based observations, statistical information, etc.) for automated processing;
design of geodetic and mathematical foundations kart;
map design;
building a digital thematic map project;
conversion of initial data into digital form;
development of the layout of the thematic content of the map;
determination of methods for automated construction of thematic content;
formation of a digital general geographical basis of the map being created;
creation of a digital thematic map in accordance with the developed project;
obtaining output cartographic products.

To enter the initial information, raster scanning devices, digitizers, halftone scanners of aerial photographic negatives are used. The resulting digital data arrays are fed into the complex of technical means for processing raster and vector data, built on the basis of workstations and personal professional computers. On the same tool base, all stages of design, transformation of initial information and creation of a digital thematic map are carried out.

The generated digital cartographic model enters the complex of technical means for generating output cartographic products, including plotters, printers, specialized output devices to photo media, etc.

The original and processed digital data are stored in the archival data storage subsystem, which is currently based on streamers or optical discs.

The areas of application of GIT are currently extremely diverse.

First of all, these are various cadastres, systems for managing a distributed economy and infrastructure. Specialized applications are developed here, for example, for systems: the electrical networks of a power company, the cable network of a telephone or television company, the complex piping of a large chemical plant, land registry, real estate operators, as well as applications such as complex systems that serve many components of the infrastructure of a city or territory

and capable of solving complex management and planning problems. The specific goals and objectives in such systems are very diverse: from inventory and accounting tasks, public reference systems to taxation, urban planning and planning tasks, planning new transport routes and optimizing transportation, distributing a network of resources and services (warehouses, shops, ambulance stations assistance, car rentals).

Another developed area of application of GIT is the accounting, study and use of natural resources, including environmental protection. Both complex systems and specialized ones are also found here: for forestry, water management, study and protection of wild fauna and flora, etc. This area of application is directly adjacent to the use of HIT in geology, both in scientific and practical tasks. It's not just tasks information support, but also, for example, the problem of predicting mineral deposits, monitoring the environmental consequences of development, etc. In geological applications, as well as in ecological ones, the role of applications that require complex programming or integration of GIT with specific processing and modeling systems is important. Especially in this regard, applications in the field of oil and gas stand out. Here, at the stage of prospecting and exploration, seismic data and very specific and developed software for their processing and analysis are widely used. There is a great need for complex solutions that link geological and other problems proper, which cannot be solved without the involvement of universal GIS.

Separately, it is necessary to single out purely transport tasks. Among them: planning new transport routes and optimizing the transportation process with the ability to take into account the distribution of resources and the changing transport environment (repairs, traffic jams, customs barriers). Particularly promising in the strategic plan are navigation systems, especially those based on satellite navigation systems using digital cartography.

A characteristic feature of the implementation of GIT at present is the integration of systems and databases into national, international and global information structures. Global projects include, for example, the GDPP - "Global Database Project", developed within the framework of the International Geosphere-Biosphere Program. On national level there are GIS in the USA, Canada, France, Sweden, Finland and other countries. In Russia, regional GIS are currently being developed, in particular, for maintaining the land cadastre and municipal administration, as well as departmental GIS, for example, in the Ministry of Internal Affairs.

An analysis of the current experience of using GIT shows that the main form of using GIT is different in terms of goals, complexity, composition and capabilities of GIS.

Modern GIS are a new type of integrated systems, which, on the one hand, include methods for processing data from existing automated systems, and on the other hand, they have specifics in the organization and processing of data

Since GIS is a complex processing of information (from its collection to storage, updating and provision), they can be considered from the following different points of view:

GIS as a management system - designed to provide decision support based on the use of cartographic data;
GIS as an automated information system - combines a number of technologies of well-known information systems (CAD and others);
GIS as a geosystem - includes technologies of photometry, cartography;
GIS as a system that uses a database is characterized by a wide range of data collected using different methods and technologies;
GIS as a modeling system, a system for providing information - is the development of document circulation systems, multimedia systems, etc.

GIS with advanced analytical capabilities are close to systems of statistical analysis and data processing, and in some cases they are integrated into unified systems, For example:

implantation of the powerful statistical package S-PLUS into the modern GIS ARC/INFO;

adding some features of spatial statistics and cartographic visualization to bulk statistical packages (SYSTAT for Windows);

development of own GIS within the framework of the SAS package - the leader among numerical information processing systems.

The most advanced GIS (usually with strong support and raster models) that have good means programming, are widely used to model natural and man-made processes, including the spread of pollution, forest fires, etc. Some conventional DBMS operating in graphical environments such as MS Windows also include the simplest cartographic visualization tools.

The presence of a wide range of development trends in different areas of information technology, whose interests converge in the field of GIT, as well as the emergence of universal packages of wide application, has led to the fact that the boundaries of the definition of GIT are becoming less clear. Therefore, at present, the concept of a fully functional GIS (full GIS) has developed.

A modern full-function GIS is a multifunctional information system designed for collecting, processing, modeling and analyzing spatial data, displaying and using them in solving computational problems, preparing and making decisions. The main purpose of a full-featured GIS is to form knowledge about the Earth, individual territories, terrain, as well as to bring the necessary and sufficient spatial data to users in a timely manner in order to achieve the greatest efficiency of their work.

A fully functional GIS should provide:

two-way communication between cartographic objects and tabular database records;
managing the visualization of objects, providing a choice of composition and form of display;
work with point, line and areal objects;
entering cards from a digitizer or scanner and editing them;
support for topological relationships between objects and verification with their help of the geometric correctness of the map, incl. isolation of areal objects, connectivity, adjoining, etc.;
support for various map projections;
geometric measurements on the map of length, perimeter, area, etc.; building buffer zones around objects and implementing other overlay operations;
creation of own designations, including new types of markers, line types, types of hatching, etc.; creation of additional elements of map design, in particular, signatures, frames, legends;
output of high-quality hard copies of maps; solving transport and other problems on graphs, for example, determining the shortest path, etc.;
work with the topographic surface.

In addition to full-featured general-purpose GIS, specialized ones are distinguished, which often have fuzzy boundaries with specialized packages that are not GIS in this sense. For example, GIS oriented to the tasks of communication planning, transport and navigation tasks, tasks of engineering surveys and design of structures.

Lower-level non-specialized GISs than full-featured general-purpose systems are commonly referred to as " personal systems cartographic visualization" (desktop mapping systems, desktop GIS), sometimes even separating this class of systems from the GIS itself. Their distinguishing feature is, first of all, limited analytical capabilities (for example, there are no overlay operations for areal objects) and poor capabilities for entering and editing cartographic basics A typical example of such a system is the GIS MapInfo, which, due to its lower complexity, is easier to learn and use and more accessible to the mass user.

To date, the number of GIS packages offered on the market amounts to several thousand. However, most of these are specialized systems. There are several dozens of real full-featured general-purpose GIS packages on the market. Basically, GIS software is developed by specialized companies, only in some cases these are products of large companies for which GIS is not the main product (IBM, Intergraph, Computervision, Westinghouse Electric Corp., McDonnel Douglas, Siemens Nixdorf). PCs (MS DOS, MS Windows) and UNIX workstations predominate in terms of the number of known packages and the number of installations.

It should be noted that at present, full-featured general-purpose GISs are mainly focused on workstations with operating system UNIX. On a PC, as a rule, systems with reduced capabilities operate. This is partly determined by the specifics of PC users, for many of whom a simple GIS is needed only as an addition to regular office software. But the main reason is the demands that a powerful GIS places on computer hardware.

Topological vector data structures are inherently complex, and the processes of their use require intensive calculations, much more than working with a conventional vector graphics, including in terms of floating point operations. Serious applications often require working with long integers and double precision real numbers. GIS requires high-resolution displays and a fast graphics card or accelerator, with more stringent palette requirements than CAD. They are rather similar to the requirements for professional printing publishing systems. Particularly high requirements for rendering speed are imposed by the typical for GIS (and less typical for CAD) task of filling with hatches a large number of closed polygons (polygons) of complex shape.

Serious projects using GIS require working with large amounts of data, from hundreds of megabytes to several tens of gigabytes. Particularly high demands on the volume of disk and main memory, as well as on the speed of a computer, are imposed by GIS with image processing in the form of raster structures, for example, in the problems of geometric correction of aerial photographs, modeling natural processes, and when working with the earth's surface relief. One high-resolution color aerial photograph of a standard format, if converted into digital form without loss of "accuracy" (24 bit, 1200 dpi), takes about 200 MB. In many problems of a regional nature, it is required to use a combined and geometrically corrected mosaic of many such images, especially since it is considered expedient to use a raster substrate from such a mosaic of aerial or space images (digital orthophoto) as a base layer for vector maps, i.e. photographs are "imprinted" on the card image. The same remark is true for working with aerospace images, which, as a rule, must be processed different ways to selectively extract various information on them (operations of various kinds of filtering, contrast transformations, operations using the fast Fourier transform, classification algorithms, discriminant, cluster and factor analysis, as well as the method of principal components). Therefore, instead of storing dozens of processing versions, which would require up to hundreds of GB per frame, it is more rational

perform them on demand. Modern specialized workstations cope with such a task, but for a PC it is still difficult. Sometimes a single frame operation on a PC takes several minutes. When it is necessary to model complex natural processes, in particular, the spread of pollution, forest fires, or apply data from aerospace surveys, the use of a specialized workstation inevitably.

It should be noted that the rate of accumulation of volumes of aerospace (especially space) data is still at the same pace or even ahead of the growth rate of computing power of PCs and workstations. Indeed, at least 800-1000 MB of satellite images are collected monthly over each area of the Earth the size of a large city. And even if we take into account that half of them are unsuitable for use in GIT applications due to cloudy conditions, it still makes up a huge flow. And one more note: the resolution of systems for collecting remote information is constantly growing, and an increase in the geometric resolution on the ground from 20 to 10 m increases the amount of data by 4 times. So every 2-4 years computer system should increase its productivity several times in order to keep up with the pace of development of information collection devices. From this it is clear that specialized workstations will remain the technical basis of powerful full-featured GIS with analytical functions for a long time to come.

Another point that makes it necessary to pay significant attention to working WVZY-stations is the fact that today the main packages of the most "serious" GIS have not yet been transferred to the PC.

The main areas of using a PC when working with GIS are currently:

the use of PCs as terminals in conjunction with workstations for working with large GIS (ARC / INFO);
use of a PC as stations for input and modification of digital terrain maps from a digitizer or scanner (PC ARC!INFO, ArcCAD);
use of a PC for GIT projects with a small amount of one-time active information (PC ARC / INFO, ArcCAD, ArcView);
using a PC for educational purposes, to get acquainted with the GIT methodology;
use of a PC in the initial stages of large projects, when the volume of the database has not yet grown, full functionality is not required on large volumes, and it is still necessary to prove the usefulness of using GIT and the need to invest serious funds.

Since modern GIS are, as a rule, complex software and information systems designed specifically for use in specific areas information activities or for solving specialized tasks, then they include:

operating system;
application software core;
modules of thematic data processing;
interactive user interface.

Thematic data processing modules include:

data input-output software;
application software for the analysis of vector and raster information;
DBMS;
pattern recognition software;
map projection selection software;
image conversion software;
cartographic generalization software;
symbol generation software, etc.

Keywords

GEOGRAPHICAL INFORMATION SYSTEMS / IMPORT SUBSTITUTION / ANALYSIS OF DOMESTIC GIS / SOFTWARE PRODUCTS / GEOGRAPHICAL INFORMATION SYSTEMS/ IMPORT SUBSTITUTION / ANALYSIS OF DOMESTIC GIS / SOFTWARE PRODUCTS

annotation scientific article on computer and information sciences, author of scientific work - Yarotskaya Elena Vadimovna, Patov Ali Mukhammedovich

At present, the country's economy in its development has taken a direction towards import substitution. The development of domestic information technologies and software is one of the priority areas. The article analyzes the state of the domestic market of geographic information systems (GIS) developers. Possibility is being considered import substitution foreign software products processing of spatial data by analogues of Russian production. The objects of analysis were software products like GeoGraph, InGeo, GeoMixer, ZuluGIS, IndorGIS, Panorama. As a result of the analysis, it turned out that there are many problems in the way of full import substitution foreign GIS, such as narrow specialization of domestic GIS, weak marketing policy for distribution to the market software products, ill-conceived interface. But the potential for the development of domestic GIS is very high. One of the main advantages of Russian information technologies in the processing of spatial data is that developers can respond more flexibly to changing market conditions.

DEVELOPMENT OF DOMESTIC GEOGRAPHICAL INFORMATION SYSTEMS IN THE CONDITIONS OF IMPORT SUBSTITUTION

Nowadays, the economy of the country has taken a direction towards import substitution in its development. The development of the domestic information technology and software is one of the priorities. The article analyzes the state of the domestic market, development of geographic information developers systems. The possibility of import substitution of foreign software products by spatial data analogues in Russia is considered. As objects of analysis became programs such as GeoGraf, InGeo, GeoMixer, ZuluGIS, IndorGIS, Panorama. As a result of the analysis we revealed that there are a lot of problems in the way of the full import substitution of foreign GIS, such as the specialization of domestic GIS, a weak marketing strategy for the distribution to market of software products , crudity of interface. However, the potential of development of domestic GIS is very large. One of the main advantages of the Russian information technology in the processing of spatial data is that developers can respond more flexibly to changing market conditions

GIS products made in the Russian Federation gained weight and functionality

Exactly seven years have passed since PC Week/RE published an overview of the prospects for universal Russian GIS (www.pcweek.ru/Year2000/N28/CP1251/GeoInfSystems/chapt1.htm) and wondered if local manufacturers would survive or be demolished powerful stream from the West. In general, the author of the article was interested in "who wins?", but in reality everything turned out quite well: both Russian and foreign developers coexist peacefully in our country and find their customers. It is gratifying that the majority of manufacturers of interesting and promising products have not sunk into oblivion - and the Central Institute of Geography of the Russian Academy of Sciences (Center for Geoinformation Research of the Institute of Geography of the Russian Academy of Sciences, geocnt. geonet.ru), and the Ufa company "Integro" (www.integro.ru), and KB "Panorama" (www.gisinfo.ru) and firm "RADOM-T" (www.objectland.ru) are well and steadily developing. True, it did not go without losses - the Laneco company, the developer of the GIS Park, left the race, and the Trisoft company (www.trisoftrus.com) no longer releases new versions of the Sinteks ABRIS geoinformation software, although it supports its users and continues to carry out GIS projects, but already on ESRI products. The St. Petersburg enterprise CSI Software (www.trace.ru), which appeared in the review seven years ago, is currently focused on the release of software for complex ISs, including a geoinformation component; in particular, it maintains the Yellow Pages website (www.yell.ru) and cartographic search engine Go2Map (www.go2map.ru). This enterprise solves transport and monitoring tasks using GIS and creates Internet cartographic applications and software for mobile devices.

GIS ObjectLand

In general, the appearance of domestically produced GIS in our country is not least due to the poverty of potential customers. Of course, the cramped financial situation in itself is not yet a guarantee of progress, but in our case it was exactly like this: almost all Russian GIS known and in demand today were created in the 90s, when the need for them became obvious, but financial the capabilities of research institutes, universities and city administrations did not allow buying expensive foreign developments. In particular, TsGI IG RAS and KB "Panorama" released their first products in 1991, the company "RADOM-T" - in 1993, and the company "Integro" - in 1998.

Stronghold of geoinformation stability in Russia

As for the CGI IG RAS, this institute is absolutely not characterized by any technological or organizational throwing. He methodically works in the field of development of technologies for creating and integrating spatial data, considering the release of software as an integral part of the preparation of regulatory documents, technological processes, training of personnel and assistance in launching specialized geoinformation centers. At present, the CGI IG RAS produces a professional geographic information system "GeoGraph GIS" (geocnt.geonet.ru/rus/gg20.html), an ActiveX-component package for creating applied GIS "GeoConstructor" (geocnt. geonet.ru/rus/gc20. html) and a tool for publishing maps on the Internet GeoConstructor Web (geocnt.geonet.ru/rus/gc_web.html). Nikolay Kazantsev, head of the Central Geographical Institute of the Russian Academy of Sciences, told PC Week/RE that in 2006 a mechanism for synchronizing non-topological layers was built into the company's products during their multi-user editing in a LAN, and the GIS functionality was developed and supplemented to ensure the organization and provision of spatial data according to " Concepts for the Creation and Development of the Spatial Data Infrastructure of the Russian Federation”, adopted by the Decree of the Government of the Russian Federation of August 21, 2006 N 1157-r. CGI IG RAS takes an active part in the development of regulatory legal documents in this area, including the first national standards. This direction is extremely important for solving practical problems - in particular, streamlining the situation with land tax, the collection of which, due to problems with the reliability and completeness of spatial data, is approximately 10-20% of the possible. "The use of geoinformation technologies and the increase in the completeness and reliability of data on land plots made it possible last year to increase the amount of land tax in the Mytishchi municipal district by more than four times," Nikolai Nikolayevich noted. "Modern GIS technologies in Russia will be effective only if they are focused on the widespread problem of incompleteness, unreliability and inconsistency of spatial data provided by various organizations about the same objects, ensuring the legal status of these data and creating systems for separating responsibility for them.

GIS “Map 2005”

A non-trivial product written in Visual SmallTalk

ObjectLand GIS, created and distributed by RADOM-T, is a multi-user system that, in addition to standard GIS functions, has ample opportunities for integrating data from external sources, managing access rights to geodata and programming opportunities for third-party developers using the system software core. GIS ObjectLand is primarily associated with the land cadastre, although this association is only historical, in fact ObjectLand is a universal GIS for use in any subject areas. ObjectLand is most intensively used in the institutions of Rosnedvizhimost, being part of the software package "Unified State Register of Lands". At present, the product is operated by approximately 1,700 land cadastral chambers in Russia. By the way, in 2005 the magazine PC Magazine/RE noted ObjectLand among the best software products in Russia and awarded the "Best Soft 2005" award. From other industries, ObjectLand is actively used in JSC Russian Railways, where, through the efforts of the department of geoinformation technologies of VNIIAS MPS, a set of works was completed to collect and prepare spatial data on the Russian railway network.

The cost of the GIS ObjectLand program for one user is 3000 rubles, for five users - 7500 rubles. As noted by the project leaders, to propose such affordable prices became possible after the transition to an online sales method. For evaluation and non-commercial use of the software, a special version is offered that does not have any functional and quantitative restrictions compared to the commercial version of the product. The only difference is that when displaying and printing maps, an inscription is always displayed in one of the corners, reminiscent of the non-commercial nature of the version used. This version of GIS ObjectLand can be used free of charge for training in all educational institutions. By the way, the company "RADOM-T" is the only one on the list that is actively trying to enter the world market, offering both Russian and English versions of the product (www.gis-objectland.com).

According to the developers, work is currently being completed on new version ObjectLand 2.7, which will provide storage of spatial data in external databases. This version supports MS SQL, Oracle, DB2, Interbase, MS Access,

MSDE, MS SQL Server Express, MySQL, PostgreSQL and Firebird. Of course, the existing possibilities for storing geodata in the internal DBMS will also remain.

GIS star on the Ufa horizon

The Integro System Research Center, once known as Albeya, is a large manufacturer of universal geoinformation software in Russia. IN last years the enterprise developed by implementing complex projects to automate property tasks, as well as the sphere of regulation of urban development for municipal and regional organizations. The company's product line includes the GIS "InGEO" (www.integro.ru/projects/gis/main_gis.htm), which allows you to generate vector topographic maps with the correct topological structure, based on the results of land inventory and equipped with plans settlements, general plans of enterprises, as well as schemes of engineering networks and communications. The InGEO software includes a data server that provides access to spatial information in a multi-user mode, an application server, the InGEO MapX OCX control element, and the InGEO MapW Web server, which includes the InGEO MarJ Java applet. In addition, the standard delivery package contains a utility for converting to various formats and a spatial data optimization tool that allows you to reduce the size of files, as well as a set of InGEO software modules in the VBScript language, which, in particular, make it possible to collectively control the visibility of maps and layers. The GIS "InGEO" has a built-in programming environment for developing software modules in VBScript and JavaScript.

In addition, Integro supplies the Monitoring-InGEO software for creating cadastral systems based on intranet technologies and capable of storing information about urban infrastructure facilities within a single application. The product is designed for architecture and urban planning authorities, land committees, municipal property management committees, BTI and housing organizations. The "Monitoring-InGEO" includes modules: "Resources", designed to account for objects of movable and immovable property, "Regulations", which allows you to maintain urban planning, environmental and architectural-historical regulations of the city, as well as "Network", which provides data collection from remote computers placed in the engineering services of the city. "Integro" also offers "Property" software for automating the activities of organizations that carry out accounting and management of buildings and premises, land plots, movable property and property complexes.

If we talk about the plans of the enterprise, then, as its director Vadim Gorbachev said, in 2007-2008. a serious reconstruction of the GIS "InGEO" is expected in order to expand the functionality of the system and greater integration with the "Monitoring" and "Property" applications. The issue of transfer in 2007-2009 is being actively discussed. company products on technology open source, in particular on the Eclipse platform. By the way, the price of the InGEO GIS network kit has not changed for many years and is 48 thousand rubles. no limit on the number of client seats. The sales growth of Integro products in 2006 compared to 2005 was 26%. The total number of officially purchased copies only network configuration GIS "InGEO" at the beginning of 2007 reached 443 sets. This system is most widespread in the Urals, Volga and Northwestern federal districts of Russia.

Military roots of civil GIS

Initially, the GIS "Panorama" was created by the topographic service of the RF Armed Forces and was intended for military purposes, but later it gained great popularity among civilian users. At the moment, Panorama CJSC, founded in 2001 by combining developers of products with the same name, is engaged in improving and promoting the solution. The company offers the widest range of software among all the lines mentioned in this review. In particular, the family includes the universal GIS "Map 2005" with tools for creating and editing electronic maps in multi-user mode, measurements and calculations, building three-dimensional models, processing raster data, generating orthomosaics and creating elevation matrices. The product also has thematic mapping tools, provides map preparation for publication, and allows you to work with GPS receivers and databases using query and reporting tools.

In addition, the enterprise releases a server GIS application GIS WebServer, developed using ASP.NET technology and operating under IIS in the .NET Framework 2.0 environment. The solution is designed to publish electronic maps and information from databases on the network and allows you to display data on objects that have a territorial reference on a topographic map, view and sort tables. The software has the functions of scaling, scrolling, resizing the image and provides search and selection of map objects. The product line also includes the "Panorama-Editor" vectorizer, the specialized software "Block of Geodetic Calculations" for processing data from field geodetic surveys, and the "Navigator 2005" software. The latter is intended for viewing and printing maps, raster images, matrices and three-dimensional models created in the GIS "Map 2005", as well as for connecting GPS receivers. There is also a GIS viewer and a MapView solution for PDAs that allows you to work with receivers of satellite navigation information.

The portfolio of "Panorama" also includes a specialized solution "Real Estate", designed to automate the collection, systematization and accounting of information about real estate objects with their subsequent linking to land plots, as well as the system for recording and registering land ownership "Land and Law", which ensures the collection , accumulation, storage and use of land cadastral data. There is also a tool for developing GIS applications GIS Toolkit - a set of cartographic components for creating applications in the visual programming environment Delphi / Kylix, Builder C ++ and libraries for Microsoft Visual C++.

Interestingly, Panorama products are used by many Russian government agencies. In particular, it was on this software that the GIS "Drugs" was based, created within the framework of the federal target program "Comprehensive measures to combat drug abuse and illicit trafficking" and, among other things, aimed at identifying areas of possible growth of drug-containing crops.

Introduction…………………………………………………………………………...3

1. Geoinformation technologies and systems…..……..…………………..4

2. Structure and functions of GIS…………………………………………………...7

Conclusion………………………………………………………………………...9

List of used sources……………………………………………...10

INTRODUCTION

The emergence of geographic information systems is attributed to the beginning of the 60s of the XX century. It was then that the prerequisites and conditions for informatization and computerization of areas of activity related to the modeling of geographical space and the solution of spatial problems appeared. Their development is related to research conducted by universities, academic institutions, defense departments and mapping services.
For the first time, the term "geographic information system" appeared in English-language literature and was used in two versions, such as geographic information system and geographic information system, very soon it also received the abbreviation GIS. A little later, this term entered the Russian scientific lexicon, where it exists in two equivalent forms: the original complete one in the form of a “geographic information system” and the reduced one in the form of a “geographic information system”. The first of them very soon became the official parade, and a completely reasonable desire for brevity in speech and texts reduced the last of them to the abbreviation "GIS".

Geoinformation systems and technologies

A geographic information system (GIS) is a multifunctional information system designed for collecting, processing, modeling and analyzing spatial data, displaying and using them in solving computational problems, preparing and making decisions. The main purpose of GIS is to form knowledge about the Earth, individual territories, terrain, as well as to bring the necessary and sufficient spatial data to users in a timely manner in order to achieve the greatest efficiency of their work.
Geoinformation technologies (GIT) are information technologies for processing geographically organized information.
The main feature of a GIS, which determines its advantages in comparison with other AIS, is the presence of a geoinformation basis, i.e. digital maps (CC) that provide the necessary information about the earth's surface. At the same time, the Central Committee must ensure:
accurate binding, systematization, selection and integration of all incoming and stored information (single address space);
complexity and clarity of information for decision-making;
the possibility of dynamic modeling of processes and phenomena;
the possibility of automated solution of problems related to the analysis of the characteristics of the territory;
the ability to quickly analyze the situation in emergency cases.
The history of the development of GIT goes back to the work of R. Tomleson on the creation of the Canadian GIS (CGIS), carried out in 1963-1971.
In a broad sense, GIT is data sets and analytical tools for working with coordinated information. GIT is not information technology in geography, but information technology for processing geographically organized information.
The essence of GIT is manifested in its ability to associate with cartographic (graphic) objects some descriptive (attributive) information (primarily alphanumeric and other graphic, sound and video information). As a rule, alphanumeric information is organized in the form of relational database tables. In the simplest case, each graphical object (and usually point, line and area objects are distinguished) is assigned a table row - an entry in the database. The use of such a connection, in fact, opens up such rich functionality for the GIT. These capabilities vary from system to system, of course, but there is a basic set of functionality that is typically found in any GIT implementation, such as the ability to answer "what is this?" questions. indicating the object on the map and "where is it?" selection on the map of objects selected by some condition in the database. The basic can also include the answer to the question "what's next?" and its various modifications. Historically, the first and most universal use of GIT is information retrieval, reference systems. Thus, GIT can be considered as a kind of extension of database technology for coordinated information. But even in this sense, it represents a new way of integrating and structuring information. This is due to the fact that in the real world most of the information relates to objects for which their spatial position, shape and relative position play an important role, and therefore, GIT in many applications significantly expand the capabilities of conventional DBMS, since GIT is more convenient and intuitive to use. and provide the DL with their "cartographic interface" for organizing a query to the database, along with the means of generating a "graphical" report. And finally, GIT adds a completely new functionality to conventional DBMSs - the use of spatial relationships between objects. The essence of GIT is manifested in its ability to associate with cartographic (graphic) objects some descriptive (attributive) information (primarily alphanumeric and other graphic, sound and video information). As a rule, alphanumeric information is organized in the form of relational database tables. In the simplest case, each graphical object (point, line or area) is assigned a table row - an entry in the database. Using this connection provides the rich functionality of GIT. These capabilities vary from system to system, of course, but there is a basic set of functionality that is usually found in any GIT implementation, such as the ability to answer "what is this? "indicating the object on the map and "where is it?" highlighting on the map objects selected according to some condition in the database. The basic ones can also include the answer to the question "what is next?" and its various modifications. Historically, the first and most universal use of GIT is - These are information retrieval and reference systems.

GIT, like any other technology, is focused on solving a certain range of tasks. Since the areas of application of GIS are quite wide (military affairs, cartography, geography, urban planning, organization of transport dispatching services, etc.), due to the specifics of the problems solved in each of them, and the features associated with a specific class of tasks being solved and with requirements for initial and output data, accuracy, technical means, etc., it is quite problematic to talk about any single GIS technology.

Structure and functions of GIS

Geographic information systems include five key components: hardware, software, data, performers and methods.

Hardware. This is the computer running the GIS. GIS are currently working on various types computing platforms, from centralized servers to individual or networked desktops.

GIS software contains the functions and tools needed to store, analyze and visualize geographic (spatial) information. The key components of the software products are:

Tools for entering and operating geographic information database management system (DBMS or DBMS);

Tools for supporting spatial queries, analysis and visualization (display);

Graphic user interface(GUI or GUI) for easy access to tools and functions.

Data is probably the most important component. Location data (geographical data) and associated tabular data may be collected and prepared by the user or purchased from vendors. In the process of managing spatial data, a geographic information system combines (or rather combines) geographic information with other types of data. For example, already accumulated data on the population, the nature of soils, the proximity of dangerous objects, etc. (depending on the task that will have to be solved using GIS) can be associated with a specific piece of an electronic map. Moreover, in complex, distributed systems for collecting and processing information, often not existing data is associated with an object on the map, but their source, which makes it possible to monitor the state of these objects in real time. This approach is used, for example, to deal with emergencies such as forest fires or epidemics.

Performers are people who work with software products and develop plans for their use in solving real problems. It may seem strange that people working with software, are considered as an integral part of the GIS, but this has its own meaning. The point is that for effective work A geographic information system needs to adhere to the methods provided by the developers, therefore, without trained performers, even the most successful development can lose all meaning.

GIS users can be both technical specialists who develop and maintain the system, and ordinary employees (end users) who are helped by GIS to solve current everyday affairs and problems.

Methods. The success and efficiency (including economic) of the use of GIS largely depends on a properly drawn up plan and rules of work, which are drawn up in accordance with the specific tasks and work of each organization.

The structure of a GIS, as a rule, includes four mandatory subsystems:

1) Data entry, providing input and / or processing of spatial data obtained from maps, remote sensing materials, etc.;

2) Storage and retrieval, which allows you to quickly obtain data for appropriate analysis, update and correct them;

3) Processing and analysis, which makes it possible to evaluate parameters, solve computational and analytical problems;

4) Representation (issuance) of data in various forms (maps, tables, images, block diagrams, digital terrain models, etc.)

Thus, the creation of maps in the circle of "duties" of GIS is far from the first place, because in order to get a hard copy of the map, most of the functions of GIS are not needed at all, or they are applied indirectly. Nevertheless, both in world and domestic practice, GIS are widely used precisely for preparing maps for publication and, to a lesser extent, for analytical processing of spatial data or managing the flow of goods and services.

CONCLUSION

The use of geoinformation systems not only changes our ideas about the ways of knowing reality, but also makes significant adjustments to theoretical basis mapping. As figuratively writes A.M. Berlyant, “electronic cards no longer smell of printing ink, but wink from the screen with bright lights of icons and chameleon-like change color depending on our desire and mood.” The synthesis of geoinformation technologies and Internet space gives grounds to talk about a special geoinformation space.

In principle, the main stages of computer mapping coincide with the stages of conventional historical research, but some specific points should also be emphasized. First of all, they are connected with the search for sources and their preparation for analysis. Spatial analysis requires, in addition to the creation of databases already familiar to the historian (mainly statistical ones), the selection of cartographic sources, and this, in turn, is impossible without an understanding of traditional methods of making maps, knowledge of the history of cartography, ideas about projections, etc. Fundamentally new for computer source science is the process of creating a source for analysis, since it involves .

Similar information.

Geoinformation technologies can be defined as a set of software and technological, methodological means of obtaining new types of information about the world. They are designed to improve the efficiency of: management processes, storage and presentation of information, processing and decision support. This consists in the introduction of geoinformation technologies in science, production, education and the application in practice of the information received about the surrounding reality.

Geoinformation technologies are new information technologies aimed at achieving various goals, including informatization of production and management processes. A feature of geographic information systems (hereinafter referred to as GIS) is that, as information systems, they are the result of the evolution of these systems and therefore include the foundations for the construction and operation of information systems. GIS as a system includes many interrelated elements, each of which is directly or indirectly connected with each other element, and any two subsets of this set cannot be independent without violating the integrity, unity of the system.

Another feature of GIS is that it is an integrated information system. Integrated systems are built on the principles of technology integration various systems. They are often used in so many different areas that their name often does not define all their capabilities and functions. For this reason, GIS should not be associated with solving problems of only geodesy or geography. "Geo" in the name of geographic information systems and technologies defines the object of research, and not the subject area of using these systems.

The integration of GIS with other information systems gives rise to their multidimensionality. In GIS, complex information processing is carried out from data collection to its storage, updating and presentation, so GIS should be considered from different perspectives.

How control systems GIS are designed to support decision making for the optimal management of land and resources, urban development, transportation and retail, use of the oceans or other spatial features. Unlike information systems, in GIS there are many new technologies for spatial data analysis, combined with electronic office technologies and optimizing solutions based on this. Because of this, GIS is an effective method for transforming and synthesizing a variety of data for management tasks.

How geosystems GIS integrate technologies for collecting information from such systems as: geographic information systems, cartographic information systems, automated mapping systems, automated photogrammetric systems, land information systems, automated cadastral systems, etc.

How database systems GIS are characterized by a wide range of data collected using different methods and technologies. At the same time, it should be emphasized that they combine the capabilities of text and graphic databases.

How simulation systems GIS uses maximum amount modeling methods and processes used in other information systems and primarily in CAD.

How systems for obtaining design decisions GIS largely use the concepts and methods of computer-aided design and solve a number of special design problems that are not found in typical computer-aided design.

How information presentation systems GIS are the development of automated documentation systems using modern technologies multimedia. They have the means of business graphics and statistical analysis, and in addition to this, thematic mapping tools. It is the effectiveness of the latter that provides a diverse solution to problems in different industries when using data integration based on cartographic information.

How applied systems GIS is unparalleled in breadth, as it is used in transport, navigation, geology, geography, military affairs, topography, economics, ecology, etc.

How mass use systems GIS allows the use of cartographic information at the level of business graphics, which makes them available to any schoolchild or businessman, and not just a specialist geographer. That is why the adoption of many decisions based on GIS technologies is not limited to the creation of maps, but only uses cartographic data.

Organization of data in GIS. Thematic data is stored in GIS in the form of tables, so there are no problems with their storage and organization in databases. The greatest problems are the storage and visualization of graphic data.

The main class of GIS data is coordinate data containing geometric information and reflecting the spatial aspect. Basic types of coordinate data: point (nodes, vertices), line (open), contour (closed line), polygon (range, region). In practice, to build real objects use more data (for example, dangling node, pseudoknot, normal node, coverage, layer, etc.). On fig. 3.1 shows the main of the considered elements of coordinate data.

The considered data types have a greater number of various relationships, which can be divided into three groups:

relationships for building complex objects from simple elements;
relationships calculated by the coordinates of objects;
relationships defined by specific description and semantics at data entry.

In the general case, spatial (coordinate) data models can have a vector or raster (cellular) representation, contain or not contain topological characteristics. This approach allows to classify models into three types: raster model; vector non-topological model; vector topological model. All these models are mutually convertible. Nevertheless, when obtaining each of them, it is necessary to take into account their features. In the GIS form of representation of coordinate data, there are two main subclasses of models: vector and raster (cellular or mosaic). A class of models is possible that contain characteristics of both vectors and mosaics. They're called hybrid models.

Rice. 3.1.

Graphical representation of a situation on a computer screen involves displaying various graphic images on the screen. The generated graphic image on the computer screen consists of two different parts from the point of view of the storage environment - a graphic "substrate" or a graphic background and other graphic objects. In relation to these other graphic images, the "image-substrate" is an "areal" or spatial two-dimensional image. The main problem in the implementation of geoinformation applications is the difficulty of a formalized description of a specific subject area and its display on an electronic map.

Thus, geoinformation technologies are intended for the widespread introduction into practice of methods and means of information interaction over spatio-temporal data, presented in the form of a system of electronic maps, and subject-oriented environments for processing heterogeneous information for various categories of users.

Let's take a closer look at the main graphical models.

Vector patterns widely used in GIS. They are built on vectors that occupy a part of the space, in contrast to the raster models that occupy the entire space. This determines their main advantage - the requirement for orders of magnitude less memory for storage and less time spent on processing and presentation, and most importantly - a higher accuracy of positioning and data presentation. When building vector models, objects are created by connecting points with straight lines, arcs of circles, polylines. Areal objects - areas are defined by sets of lines.

Vector models are used primarily in transport, utility, marketing GIS applications. GIS systems that work primarily with vector models are called vector GIS. In real GIS, they do not deal with abstract lines and points, but with objects containing lines and areas occupying a spatial position, as well as with complex relationships between them. Therefore, a full vector GIS data model displays spatial data as a collection of the following main parts: geometric (metric) objects (points, lines and polygons); attributes - features associated with objects; connections between objects. Vector models (of objects) use as an elementary model a sequence of coordinates forming a line. A line is a boundary, segment, chain or arc. The main types of coordinate data in the class of vector models are defined through the base element line as follows. A point is defined as a degenerate line of zero length, a line is defined as a line of finite length, and an area is represented by a sequence of connected segments. Each section of the line can be the boundary for two areas or two intersections (nodes). The common boundary segment between two intersections (nodes) has different names that are synonymous in the GIS domain. Graph theorists prefer the term "edge" to the word "line", and use the term "vertex" to denote an intersection. The US National Standard officially sanctioned the term "chain". On some systems ( Arcinfo, GeoDraw) the term "arc" is used. Unlike ordinary vectors in geometry, arcs have their own attributes. Arc attributes designate the polygons on either side of them. In relation to arc sequential encoding, these polygons are referred to as left and right. The concept of an arc (chain, edge) is fundamental to vector GIS.

Vector models are obtained in different ways. One of the most common is the vectorization of scanned (bitmap) images.

Vectorization- the procedure for selecting vector objects with bitmap and getting them in vector format. For vectorization it is necessary high quality(distinct lines and contours) bitmap images. To ensure the required clarity of the lines, sometimes you have to improve the image quality.

During vectorization, errors are possible, the correction of which is carried out in two stages:

1) correction of a bitmap image before its vectorization;
2) correction of vector objects.

Vector models display continuous objects or phenomena using discrete data sets. Therefore, we can talk about vector discretization. At the same time, the vector representation makes it possible to reflect greater spatial variability for some regions than for others, compared with a raster representation, which is due to a clearer display of boundaries and their less dependence on the original image (image) than with a raster display. This is typical of social, economic, demographic phenomena, the variability of which is more intense in a number of regions.

Some objects are vector objects by definition, such as the boundaries of the corresponding land plot, the boundaries of districts, etc. Therefore, vector models are commonly used to collect coordinate geometry data (topographic records), legal boundary data, and so on.

Features of vector models: in vector formats, a dataset is defined by database objects. The vector model can organize the space in any sequence and gives "random access" to the data. It is easier to carry out operations with linear and point objects, for example, network analysis - the development of traffic routes along the road network, the replacement of symbols. In raster formats, a point feature must occupy an entire cell. This creates a number of difficulties related to the ratio between the size of the raster and the size of the object.

As for the accuracy of vector data, here we can talk about the advantage of vector models over raster ones, since vector data can be encoded with any conceivable degree of accuracy, which is limited only by the capabilities of the method of internal representation of coordinates. Typically, 8 or 16 decimal places (single or double precision) are used to represent vector data. Only some classes of data obtained during the measurement process correspond to the accuracy of vector data: these are data obtained by precise surveying (coordinate geometry); maps of small areas based on topographic coordinates and political boundaries defined by precise surveying.

Not all natural phenomena have characteristic clear boundaries that can be represented in the form of mathematically defined lines. This is due to the dynamics of phenomena or ways of collecting spatial information. Soils, vegetation types, slopes, wildlife habitats - all these objects do not have clear boundaries. Typically, lines on a map are 0.4 mm thick and are often considered to represent the uncertainty of an object's position. In a raster system, this uncertainty is given by the cell size. Therefore, it should be remembered that in a GIS, the size of the raster cell and the uncertainty in the position of the vector object, and not the accuracy of the coordinates, give the real indication of accuracy. To analyze relationships in vector models, it is necessary to consider their topological properties, i.e. consider topological models, which are a type of vector data models.

IN raster models discretization is carried out most in a simple way- the entire object (the study area) is displayed in spatial cells that form a regular network. Each cell of the raster model corresponds to the same size, but different characteristics (color, density) surface area. The model cell is characterized by one value, which is the average characteristic of the surface area. This procedure is called pixelation. Raster models are divided into regular, irregular And nested(recursive or hierarchical) mosaics. There are three types of flat regular tilings: square (Figure 3.2), triangle, and hexagon (Figure 3.3).

Rice. 3.2.

Rice. 3.3.

The square shape is convenient for processing large amounts of information, the triangular shape is for creating spherical surfaces. Triangular networks of irregular shape are used as irregular mosaics ( Triangulated Irregular Network - TIN) and Thyssen polygons (Figure 3.4). They are convenient for creating digital models of terrain marks from a given set of points.

Thus, the vector model contains information about the location of the object, and the raster model contains information about what is located at one or another point of the object. Vector models are binary or quasi-binary.

Rice. 3.4.

If the vector model provides information about where this or that object is located, then the raster model provides information about what is located in one or another point of the territory. This determines the main purpose of raster models - the continuous display of the surface. In raster models, a two-dimensional element of space, a pixel (cell), is used as an atomic model. An ordered set of atomic models forms a raster, which, in turn, is a model of a map or geo object. Vector models are binary or quasi-binary. Bitmaps allow you to display halftones and color shades. Typically, each raster element or each cell should have only one density or color value. This does not apply in all cases. For example, when the boundary of two coverage types can pass through the center of a raster element, the element is given a value that characterizes the majority of the cell or its center point.

Some systems allow multiple values for a single raster element. For raster models, there are a number of characteristics: resolution, value, orientation, zones, position.

Permission- the minimum linear size of the smallest portion of the displayed space (surface), displayed by one pixel. Pixels are usually rectangles or squares, less often triangles and hexagons are used. A raster with a smaller cell size has a higher resolution. High resolution implies an abundance of details, a lot of cells, a minimum cell size.

Meaning- an element of information stored in a raster element (pixel). Since typed data is used during processing, i.e. the need to define raster model value types. The type of values in the raster cells is determined both by the real phenomenon and by the features of the GIS. In particular, different systems can use different classes of values: integers, real (decimal) values, literal values. Integer numbers can serve as optical density characteristics or codes indicating a position in an attached table or legend. For example, the following legend is possible, indicating the name of the soil class: O - empty class, 1 - loamy, 2 - sandy, 3 - gravelly, etc.

Orientation- the angle between the direction to the north and the position of the columns of the raster.

Zone raster model includes cells adjacent to each other that have the same value. A zone can be individual objects, natural phenomena, ranges of soil types, elements of hydrography, etc. To indicate all zones with the same value, the concept of "zone class" is used. Naturally, not all image layers may have zones. The main characteristics of the zone are its meaning and position.

buffer zone- a zone, the boundaries of which are removed at a known distance from any object on the map. Buffer zones of various widths can be created around selected objects based on tables of associated characteristics.

Position usually given by an ordered pair of coordinates (row number and column number) that uniquely define the position of each element of the displayed space in the raster. When comparing vector and raster models, we note the convenience of vector models for organizing and working with object relationships. However, by using simple tricks, such as including relationships in attribute tables, you can organize relationships in raster systems as well.

Questions need to be addressed accuracy display in raster models. In raster formats, in most cases it is not clear whether the coordinates refer to the center point of a pixel or to one of its corners. Therefore, the anchoring accuracy of a raster element is defined as 1/2 of the width and height of the cell.

Raster models have the following advantages:

The raster does not require a preliminary acquaintance with the phenomena, the data is collected from a uniformly distributed network of points, which makes it possible in the future to obtain objective characteristics of the objects under study based on statistical processing methods. Due to this, raster models can be used to study new phenomena about which no material has been accumulated. Due to its simplicity, this method is most widely used;
raster data is easier to process using parallel algorithms and thus provide higher performance compared to vector data;
some tasks, such as creating a buffer zone, are much easier to solve in raster form;
many raster models allow you to enter vector data, while the reverse procedure is very difficult for vector models;
rasterization processes are much simpler algorithmically than vectorization processes, which often require expert judgment.

A digital map can be organized into multiple layers (overlays or underlay maps). Layers in GIS represent a set of digital cartographic models built on the basis of association (typing) of spatial objects that have common functional features. The set of layers forms the integrated basis of the graphical part of the GIS. An example of integrated GIS layers is shown in fig. 3.5.

Rice. 3.5.

An important point in the design of a GIS is the dimension of the model. Two-dimensional coordinate models (2D) and three-dimensional (3D) are used. Two-dimensional models are used to build maps, while three-dimensional models are used for modeling geological processes, designing engineering structures (dams, reservoirs, quarries, etc.), modeling gas and liquid flows.

There are two types of 3D models:

1) pseudo-three-dimensional, when the third coordinate is fixed;
2) true three-dimensional representation.

Most modern GIS perform complex information processing:

collection of primary data;
accumulation and storage of information;
different kinds modeling (semantic, simulation, geometric, heuristic);
automated design;
documentation support.

The many tasks that arise in life have led to the creation of various GIS that can be classified according to the following criteria:

1) by functionality :
- full-featured general-purpose GIS,
- specialized GIS are focused on solving a specific problem in any subject area,
- information and reference systems for home and information and reference use.

The functionality of a GIS is also defined architectural principle their constructions:

closed systems - do not have expansion options, they are able to perform only the set of functions that is uniquely defined at the time of purchase,
open systems they are easy to adapt, expandable, as they can be completed by the user himself using a special apparatus (built-in programming languages);
2) spatial (territorial) coverage:
- global (planetary),
- nationwide,
- regional,
- local (including municipal);
3) problem-thematic orientation:
- general geographic,
- environmental and nature management,
- sectoral (water resources, forest management, geological, tourism, etc.);
4) the way geographic data is organized:
- vector,
- raster,
- vector-raster GIS.

As data sources for the formation of GIS are:

cartographic materials(topographic and general geographical maps, maps of administrative-territorial division, cadastral plans, etc.). Information received from maps is georeferenced, so it is convenient to use it as a base GIS layer. If there are no digital maps for the study area, then the graphic originals of the maps are converted into digital view;
remote sensing data(hereinafter referred to as RSD) are increasingly being used to form GIS databases. ERS primarily includes materials obtained from space carriers. For remote sensing, a variety of technologies for obtaining images and transmitting them to Earth are used, carriers of imaging equipment (spacecraft and satellites) are placed in different orbits and equipped with different equipment. Thanks to this, images are obtained that differ in different levels of visibility and detail in the display of objects of the natural environment in different spectral ranges (visible and near infrared, thermal infrared and radio range). All this leads to a wide range of environmental problems solved with the use of remote sensing. Remote sensing techniques include aerial and ground surveys and other non-contact methods such as hydroacoustic seabed surveys. The materials of such surveys provide both quantitative and qualitative information about various objects of the natural environment;
materials of field surveys of territories include data from topographic, engineering and geodetic surveys, cadastral surveys, geodetic measurements of natural objects performed by levels, theodolites, electronic total stations, GPS receivers, as well as the results of surveys of territories using geobotanical and other methods, for example, studies on the movement of animals, soil analysis and etc.;
statistical data contain data from state statistical services for various sectors of the national economy, as well as data from stationary measuring observation posts (hydrological and meteorological data, information on environmental pollution, etc.));
literature data(reference publications, books, monographs and articles containing a variety of information on certain types of geographical objects).

In GIS, only one type of data is rarely used, most often it is a combination of various data for any territory.

The main areas of GIS use:

electronic cards;
urban economy;
state land cadastre;
ecology;
remote sensing;
economy;
special military systems.

In practice, GIS such as Arcinfo And ArcView GIS. Both systems were developed by an American company ESRI(www.esri.com, www.dataplus.ru) and are very common in the world.

From relatively simple Western GIS, which began their pedigree with the analysis of territories in the amount necessary for business and relatively simple applications, we can call the system mapinfo, which is also very widespread in the world. This system is progressing very quickly and today can compete with the most advanced GIS.

Corporation Intergraph(www.intergraph.com) supplied by GIS mge, based on an AutoCAD-like system microstation, produced in turn by the company Bendy. System MGE is a whole family of various software products that help to solve the largest number of problems that exist in the field of geoinformatics.

All of these products also have Internet GIS servers that allow you to publish digital maps on the Internet. True, we have to talk only about viewers, since today it is impossible to provide editing of topological maps from the side of a remote Internet client due to the underdevelopment of both GIS and Internet technologies.

Just recently entered the GIS market and microsoft, thus confirming that GIS will become in the near future such a system that every user who has the slightest respect for himself should have on his computer, as he has today excel or word. Microsoft released a product mappoint (Microsoft MapPoint 2000 Business Mapping Software), which will be included in office 2000. This component of the office product will focus primarily on business planning and analysis.

Repetition of the concept Arcinfo, but much inferior to the latter in terms of functional completeness is the domestic system GeoDraw, developed at TsGI IGRAN (Moscow). Its capabilities are limited today mainly by small-scale maps. From our point of view, the “elder” of domestic geoinformatics, GIS, looks much “stronger” here Sinteks ABRIS. In the latter, functions for the analysis of spatial information are well represented.

In geology, the position of GIS PARK (Laneco, Moscow) is strong, which also implements unique methods for modeling the corresponding processes.

Two domestic systems can be considered the most "advanced" in the field of presentation and duty of large-scale saturated maps of cities and master plans of large enterprises: GeoCosm(GEOID, Gelendzhik) and InGeo (CSI Integro, Ufa, www.integro.ru). These systems are among the youngest and therefore were developed immediately using the most modern technologies. And the InGeo system was developed not so much by surveyors as by specialists who consider themselves professionals in the field of simulation modeling and cadastral systems.

In general, almost every organization in Russia creates its own GIS. However, this process is very difficult, and the probability of its completion unsuccessfully is incomparably higher than the probability of a problem-free implementation, not to mention the possibility of a commercial product that allows alienation from developers.

annotation scientific article on computer and information sciences, author of scientific work - Yarotskaya Elena Vadimovna, Patov Ali Mukhammedovich

Related Topics scientific works on computer and information sciences, author of scientific work - Yarotskaya Elena Vadimovna, Patov Ali Mukhammedovich

DEVELOPMENT OF DOMESTIC GEOGRAPHICAL INFORMATION SYSTEMS IN THE CONDITIONS OF IMPORT SUBSTITUTION