Cadastral engineers, designers, geologists and other specialists often face the need to use cartographic data in their work. Modern developments allow receiving satellite images of the terrain in the smallest details, and specially created software - using this information for analytical purposes and displaying them in the required format.
Let's talk about structures that allow us to generalize and study geographical material for the implementation of the most reasonable and optimal measures in each case.
Definition of GIS (GIS): how the abbreviation is deciphered and what it is
Geographic Information Systems (GIS) are advanced computer technologies that are used to create maps and evaluate actually existing objects, as well as incidents occurring in the world. At the same time, visualization and spatial surveys are combined with standard processes with databases: entering information and obtaining statistical results.
It is the indicated characteristics that allow these programs to be widely used to solve many problems:
Analysis of physical phenomena and events on the planet.
Comprehension and designation of their main reasons.
The study of overpopulation.
Planning for promising solutions in urban planning.
Assessment of the results of current business activities.
Environmental problems - contamination of localities, reduction of forest areas.
In addition to global goals, with the help of such security it is possible to regulate private situations, for example:
Finding the best path between points.
Choosing a convenient location for the company.
Finding the desired building at.
Municipal tasks.
Geographical analysis is not just an emerging trend. But the technologies we are considering are most consistent with the requirements of our time. This is the most effective, efficient and convenient process that automates the procedure for collecting the corresponding material and its processing.
Today, geographic information systems is a profitable area of \u200b\u200bactivity in which millions of people are employed in different countries. In Russia alone, more than 200 different companies develop and implement such technologies in all areas of business.
It has several constituent elements.
Equipment. These are various types of computer platforms, from personal computers to global centralized servers.
Software.There are all the necessary tools for obtaining, processing and visualizing the material. The individual components can be used to designate components for:
Introduction and manipulation of information;
Database Management (DBMS);
Mapping spatial queries;
Access (interface).
What are possible manipulations in programs
Utilities perform several processes:
InputIn this case, the material is converted to the required digital format. During digitization, paper cards are taken as a basis, which are processed on scanner devices. This is true for large objects, for small tasks you can enter information through a digitizer.
Manipulation. Technologies have different ways of modifying materials and designating certain parts necessary to perform an immediate task. For example, they allow you to bring the scale from different elements to a single value for further general processing.
Control. With a significant amount of information and a large number of users, it is rational to use database management systems to collect and structure material. The most commonly used relational model is when information is stored in tables.
Request and analysis. The program allows you to get answers to many primitive and more detailed questions, ranging from the identity of the owner of the site and ending with the predominant types of soil under the mixed object. It is also possible to create templates for finding a specific type of request. For analysis, tools such as proximity assessment and overlay research are used.
Visualization. This is the desired result of most spatial actions. Maps are equipped with accompanying documentation, volumetric images, tabular values \u200b\u200band graphs, multimedia and photographic reports.
GIS Types
The classification of geographic information systems is based on the principle of territorial coverage:
Global(national and subcontinental) - provide an opportunity to assess the situation on a global scale. Due to this, it is possible to predict and prevent natural and man-made disasters, assess the size of the disaster, plan the elimination of consequences and organize humanitarian assistance. Used worldwide since 1997.
Regional (local, subregional, local) - operate at the municipal level. Such technologies reflect many key areas: investment, property, navigation, public safety and others. They help to make decisions in the development of a certain area, which helps to attract capital to it and the growth of its economy.
GIS stores factual information about objects in the form of a selection of thematic layers, united by the principle of geographical location. This approach provides a solution to the diverse tasks of reorganizing the terrain and conducting events.
To find the location of the object, the coordinates of the point, its address, index, land number, etc. are used. This information is applied to the maps after the geocoding procedure.
Technologies can work with raster and vector models.
AT vector form the material is encoded and saved as a set of coordinates. It is more suitable for stable elements with constant properties: rivers, pipelines, landfills.
Raster scheme includes blocks of information about the individual components. It is adapted to work with variable characteristics, such as soil types and the availability of objects.
Related innovations
GIS works closely with other applications. Consider the connection and the main differences with similar information technologies.
DBMS They serve for the accumulation, storage and coordination of various materials; therefore, they are often included in the software support of geographical systems. Unlike the latter, they do not have tools for estimating and spatial representation of data.
Desktop mapping tools. Maps are used as information, but they have limited capabilities for their management and analysis.
Remote Sensing and GPS. Here, information is collected using special sensors: on-board cameras of aircraft, sensors of global positioning and others. In this case, the material is collected in the form of pictures with the implementation of their processing and study. However, due to the lack of some tools, they cannot be considered geographic information systems.
CAD These are programs for drawing up various drawings, floor plans and architectural developments. They use a set of elements with fixed parameters. Many of them have the ability to import values \u200b\u200bfrom a GIS.
Among such utilities, it is worth noting the products of ZWSOFT:
Powerful and affordable GIS designed to import, export and manage geospatial data. When choosing a version to use with ZWCAD / AutoCAD, this application runs inside the CAD platform and allows users to exchange geospatial data between the platform drawing and GIS files, GIS servers or GIS data stores, load vector and raster maps and substrates, and manage attribute data and tables data.
- analogue of GeoniCS. Allows you to automate design and survey work. At the same time, drawings are created that comply with current design standards and standards. It contains six modules, the use of which solves various engineering, including geological, problems.
- An analogue of the GeoniCS Exploration. It analyzes and interprets the results of laboratory and field studies, performs statistical processing according to specified parameters, calculates various normative and calculated indicators, and generates reports according to the standards of the CIS countries.
- A utility for cadastral engineers with a full set of tools that automate the preparation of documents. Constant updating allows you to always provide up-to-date information on paperwork in accordance with the requirements of inspection bodies.
- computer-aided design system for architects, engineers, designers. It has a new core based on hybrid technologies that combines a clear interface, Unicode support, the ability to create three-dimensional models based on their cross sections. It has a built-in ability to insert raster maps for georeferenced files (geographical registration).
GIS Examples for Beginners
There are a lot of programs created for the purposes of such a geographical analysis. For example, consider some of them.
Mapinfo
The main functionality is:
the use of a clear and convenient exchange scheme for transferring data to other structures;
the active window can be saved in different formats: bmp, tif, jpg and wmf;
support for a significant number of geographical projections and coordinate systems;
you can enter material through a digitizer.
Using the utility, you can make thematic maps and build 3D landscapes.
Datagraf
A tool for spatial visualization, modeling of situations, construction of synthetic indicators. Optimal for learning the basics of computer mapping in educational institutions.
The program allows you to:
create vector maps;
bind to each element an unlimited number of thematic databases;
copy data to another file through the clipboard;
manually change the characteristics of objects and their location.
A simple tool for mastering a basic level. It solves mainly illustrative tasks. Allows you to create digitized cards based on a regular picture and in any graphic format.
GIS application
The possibilities for using geographic technologies are very extensive. Among the areas where these systems are most applicable, we can distinguish:
Land tenure. Utilities for compiling inventories, calculating areas of elements, marking the boundaries of land.
Managing the placement of objects. Here, their application is relevant for building an architectural plan, coordinating a network of industrial, commercial and other points of special purpose.
District development. Engineering surveys of specific places, solving problems of optimizing infrastructure and attracting investors are currently impossible without a detailed study using similar structures.
Protection of Nature. Programs allow environmental monitoring, resource use planning.
Prediction of emergencies. Tracking changes in different geological conditions allows us to predict the possibility of disasters, develop measures to prevent them and minimize losses from them.
Brief Summary
We gave a transcript of the concept of GIS, examined in detail what geographic information systems are and where they are used. In conclusion, we say that this is a very promising area that is actively developing. Without the use of such technologies, it is already impossible to imagine the work of specialists in many fields.
GIS technologies today are used almost everywhere - in forestry, construction, cartography, ecology, seismology and so on. They are studied at universities and research institutes. GIS technology is an entire industry that affects almost all aspects of human life. But at the same time, it is very difficult to give a clear definition to this type of technology. After all, this is not just a set of systematized knowledge. This is a special view of the world. Our GIS technology will tell you how GIS technologies work and what they are intended for.
What is a GIS?
GIS is a geographic information system. It allows you to map the objects of the surrounding world, and then analyze them by a huge number of parameters, visualize them and based on these data to predict a variety of events and phenomena. Such a powerful technology allows us to solve a huge number of tasks using GIS, both global and private. GIS technology can stand in the service of all mankind, preventing environmental disasters or helping to solve the problems of overpopulation of individual regions.
GIS can also be used for the needs of individual companies, to establish an effective business with its help. For example, a transportation company using special databases can select the best routes for their vehicles, utilities - to lay communications to new homes and so on.
How does GIS work?
The information system is a huge database of digital data converted to digital format. They are detailed layers, united by geographical feature and tied to a specific coordinate system. Any events occurring can be successfully tracked on such a database. In addition, with its help you can find almost anywhere in the world, track the movement of almost any object.
GIS databases are capable of performing five different tasks. You can enter relevant data into the database, and in most cases this happens automatically using a scanner. You can manipulate the data, scale it as you wish, collect the information necessary to solve a specific problem. Like regular databases, a GIS system can be managed. This is done through a range of integrated applications.
A large amount of data contained in the database gives ample opportunities for analysis on a variety of parameters. You can find free sites for building a house, optimally form traffic flows, analyze the proximity of various objects (for example, determine the number of people living within walking distance from your store), superimpose various indicators on each other and analyze the resulting picture.
The last task that GIS allows you to do is visualize data. You can get maps, charts, tables and even photos of the area you are interested in. These data are of great importance both for scientific research and for the work of individual companies and organizations.
Where are GIS technologies applied?
From the descriptions proposed above, it becomes clear that GIS technologies are widely used in various fields of activity. But what exactly can they do? Here are a few examples that show what the real benefits of GIS technology are.
· By identifying the relationship between various indicators, you can develop more efficient work technologies and save quite a lot of money. Analyze how the type of soil, climate and productivity of certain crops are related, and you will understand where it is best to cultivate them.
· Having set certain search criteria, you can easily find the object you need, and, without spending too much time, engage in its development. Finding an apartment that will have a certain number of rooms, the size of the kitchen and at the same time will be located close to your children’s work and school is now very simple.
· GIS can have a positive impact on business processes taking place within organizations. A huge database can be useful in any field, because it provides opportunities for clear work planning. Utilities can not only quickly monitor equipment wear and plan maintenance work, but also notify those residents who are affected by this.
· Today, maps of cities and localities are quickly becoming obsolete - new construction is underway, roads are being designed. GIS allows you to track these changes and make them to the database almost instantly. Launched into a virtual network, such a card will always have the latest data at hand.
GIS technology is not just a computer database. These are great opportunities for analyzing, planning and regularly updating information. GIS technologies today are used in almost all areas of life, and this helps to really effectively solve many problems.
GIS (stands for "Geographic Information Systems") - computer systems that provide the ability to display data on the screen in electronic form. GIS images are for next-generation maps.
Geography on screen
Such maps can be supplied, in addition to geographic and other data from the field of statistics, demography, etc. With them, different types of analytical operations are possible, inaccessible to old paper media.
Technical support for electronic maps exists in the form of a huge number of analytics, editing tools, extensive databases. When creating and using them, a lot of modern tools are involved - from scanners to space satellites taking pictures of the earth's surface.
The information obtained with the help of new technologies finds application not only among geographers, but also among business, construction, marketing, and government. Even housewives know what geographic information systems are. And they quite successfully use electronic cards!
GIS - definition and basic concepts
What exactly does this term mean? Geoinformation systems (GIS) - the name of systems whose purpose is the collection, storage and analysis of spatial data, as well as their graphical visualization. GIS refers to a new generation of computer technology. The science that studies the applied and technical aspects of working with GIS is geoinformatics.
GIS is a successful combination of the ability to work with databases (queries, analytics) and spatial visualization, typical for maps. Data storage in such a system is carried out on thematic layers, tied to a geographical location. GIS works with both raster and vector data, so any task related to spatial information can be effectively solved with their help.
What sets them apart
The characteristic features that the geographic information system possesses include advanced analytics, work with huge amounts of information, and the availability of special tools for processing spatial data.
Their main advantages are user friendliness (data in three-dimensional measurement is the easiest to read), the ability to integrate information accumulated by various sources, create a single array for collective use.
Then - automatic analysis of geospatial data and a report, the use of decoding of aerial and satellite imagery, previously created schemes and plans of the area, which increases the efficiency of the application by an order of magnitude. Significant saving of time resources and the ability to create three-dimensional models of geographical objects.
Main tasks
GIS functions are a series of operations for:
- data input (digital cards are created automatically),
- data management (all of them are stored with the possibility of subsequent processing and use),
- their request and analysis by comparing many parameters,
- visualization of the received and processed data in the form of interactive maps.
Reports on each object can take the form of a graph, chart or three-dimensional image.
GIS features
Using the GIS system, it becomes possible to determine the presence, quantity and relative position of all available objects in a given territory. In addition, with its help, for example, an analysis of geospatial data characterizing the density of settlement, etc., is carried out and various changes in time are determined.
With the help of GIS systems, it has become possible to simulate the alleged situation regarding, for example, adding a new object - a road, housing estate, etc.
GIS - classification
There are several classifications of these systems. If we divide them according to the principle of territorial coverage, then each GIS can be attributed to global, subcontinental, national, regional, subregional, as well as local or local systems.
Based on the management level, these systems consist of federal, regional, municipal and corporate.
They are distinguished by functionality. GIS (abbreviation decoding is understandable to a large number of users) can be either fully functional or specialized, designed to solve certain problems - for example, viewing data, entering and processing it.
Depending on the subject area, GIS can be attributed to cartographic, geological, environmental, as well as municipal or urban.
Integrated geographic information systems are those in which, in addition to standard functionality, it is possible to digitally process images. Full-scale GIS reproduces data at any selected scale. Spatio-temporal systems make it possible to operate with information in the past or future tense.
Where are GIS used?
GIS is a versatile tool with an extensive scope. Which one?
- A typical area of \u200b\u200btheir use is land management, cadastre compilation, calculation of areas and setting boundaries of land plots. Just to solve such problems, the first such systems were created.
- Another area is the management of production infrastructure facilities, their accounting, planning, and inventory. Creation and placement of a network of objects for a specific purpose - shops, gas stations, etc.
- Engineering surveys and planning in the field of architecture and construction, solving problems of developing the territory and optimizing its infrastructure.
- Creation of thematic maps.
- Management of all types of transport - from land to water and air.
Other areas
Environmental protection activities, environmental activities, planning and management of natural resources, environmental monitoring, modeling of environmental processes.
The field of geology and mining. With the help of GIS, it became possible to calculate the mineral reserve based on exploratory drilling samples and modeling the structure of the field.
Further development
Since the 70s. Thanks to state support, experimental projects appeared on the use of GIS in navigation and garbage collection systems, traffic, etc.
Since the 80s a period of development began on a commercial basis. The market was filled with a mass of software, all kinds of applications appeared, the number of users who found out what GIS technology was, exceeded the number of professional professionals.
In the present period, which can be called custom, due to the high competition among manufacturers, it became possible to create thematic consumer groups, conduct teleconferences, and form a unified world geostructure.
About the prospects of GIS
The new stage of evolution in the development of GIS can be considered the emergence of geodesign, which is now required everywhere - from the sphere of land use and environmental protection to the planning of new infrastructure and construction projects, as well as in the maintenance of public networks, etc.
The future belongs to GIS technologies that contain the beginnings of artificial intelligence. Modern GIS - this is the latest computer development based on the use of space and aerial photography, serving to implement global government programs.
Now GIS-systems are developing at an unprecedented pace and are among the most commercially interesting solutions. In Russia today, about 200 different organizations are engaged in their development and implementation, which allows us to talk about competition with Western manufacturers. It is no secret to anyone that the new technologies have enormous prospects based on the further development of computer information processing tools.
GIS are modern geographic information mobile systems that have the ability to display their location on a map. The basis of this important property is the use of two technologies: geoinformation and If the mobile device has a built-in GPS receiver, then using such a device you can determine its location and, therefore, the exact coordinates of the GIS itself. Unfortunately, geoinformation technologies and systems in the Russian-language scientific literature are represented by a small number of publications, as a result of this there is almost no information about the algorithms that underlie their functionality.
GIS classification
The division of geographic information systems occurs according to the territorial principle:
- Global GIS It has been used to prevent man-made and natural disasters since 1997. Thanks to these data, it is possible to predict the magnitude of the disaster in a relatively short time, draw up a plan to eliminate the consequences, assess the damage caused and human losses, as well as organize humanitarian actions.
- Regional geographic information system developed at the municipal level. It allows local authorities to predict the development of a particular region. This system reflects almost all important areas, for example, investment, property, navigation and information, legal, etc. It is also worth noting that, thanks to the use of these technologies, it became possible to act as a guarantor of the life safety of the entire population. The regional geographic information system is currently being used quite effectively, contributing to attracting investments and the rapid growth of the region's economy.
Each of the above groups has certain subspecies:
- The global GIS includes national and subcontinental systems, usually with state status.
- In the regional - local, subregional, local.
Information about these information systems can be found in special sections of the network, which are called geoportals. They are placed in the public domain for review without any restrictions.
Principle of operation
Geographic information systems work on the principle of compiling and developing an algorithm. It is he who allows you to display the movement of an object on a GIS map, including the movement of a mobile device within the local system. To depict a given point in the terrain drawing, you need to know at least two coordinates - X and Y. When displaying the movement of an object on the map, you will need to determine the sequence of coordinates (Xk and Yk). Their indicators should correspond to different points in time of the local GIS system. This is the basis for determining the location of an object.
This sequence of coordinates can be extracted from the standard NMEA file of the GPS receiver that performed the real movement on the ground. Thus, the basis of the algorithm considered here is the use of NMEA file data with the coordinates of the object's trajectory over a specific territory. The necessary data can also be obtained as a result of modeling the motion process based on computer experiments.
GIS Algorithms
Geographic information systems are built on the source data, which are taken to develop the algorithm. As a rule, this is a set of coordinates (Xk and Yk) corresponding to a certain trajectory of the object in the form of an NMEA file and a digital GIS map in a selected area. The task is to develop an algorithm that displays the motion of a point object. In the course of this work, three algorithms underlying the solution of the problem were analyzed.
- The first GIS algorithm is the analysis of NMEA file data in order to extract a sequence of coordinates (Xk and Yk) from it,
- The second algorithm is used to calculate the path angle of the object, while the parameter is counted from the east direction.
- The third algorithm is to determine the course of an object relative to the countries of the world.
Generalized Algorithm: General Concept
The generalized algorithm for displaying the motion of a point object on a GIS map includes the three algorithms indicated above:
- nMEA data analysis;
- calculation of the path angle of the object;
- determining the course of an object relative to countries of the entire globe.
Geographic information systems with a generalized algorithm are equipped with the main control element - a timer (Timer). Its standard task is that it allows the program to generate events at certain intervals. Using this object, you can set the required period for performing a set of procedures or functions. For example, for a repeatedly executed time interval countdown of one second, the following timer properties must be set:
- Timer.Interval \u003d 1000;
- Timer.Enabled \u003d True.
As a result, every second, the procedure of reading the X, Y coordinates of the object from the NMEA file will start, as a result of which this point with the obtained coordinates is displayed on the GIS map.
The principle of the timer
The use of geographic information systems is as follows:
- Three points are marked on the digital map (symbol 1, 2, 3), which correspond to the trajectory of the object at different times tk2, tk1, tk. They are necessarily connected by a solid line.
- Turning on and off the timer that controls the display of the movement of an object on the map is carried out using buttons that are pressed by the user. Their meaning and a certain combination can be studied according to the scheme.
NMEA file
Let us briefly describe the composition of the NMEA GIS file. This is an ASCII document. In fact, it is a protocol for exchanging information between a GPS receiver and other devices, such as a PC or PDA. Each NMEA message begins with a $ sign, followed by a two-character device designation (for the GPS receiver - GP) and ends with the sequence \\ r \\ n - a carriage return and a new line. The accuracy of the data in the notification depends on the type of message. All information is contained in one line, and the fields are separated by commas.
In order to understand how geographic information systems work, it is quite enough to study a widely used message such as $ GPRMC, which contains a minimal but basic data set: the location of the object, its speed and time.
Consider, using a specific example, what information is encoded in it:
- date of determining the coordinates of the object - January 7, 2015;
- uTC world coordinates - 10h 54m 52s;
- the coordinates of the object are 55 ° 22.4271 "N and 36 ° 44.1610" E
We emphasize that the coordinates of the object are presented in degrees and minutes, and the last indicator is given up to four decimal places (or a point as a separator of the integer and fractional parts of a real number in the USA format). In the future, you will need the fact that in the NMEA file the latitude of the object’s location is located after the third comma, and longitude after the fifth. At the end of the message is transmitted after the character "*" in the form of two hexadecimal digits - 6C.
Geographic Information Systems: Examples of Algorithm Design
Consider an algorithm for analyzing an NMEA file to extract a set of coordinates (X and Yk) corresponding to an object. It is composed of several successive steps.
Determining the Y coordinate of an object
NMEA Data Analysis Algorithm
Step 2. Find the position of the third comma in the line (q).
Step 3. Find the position of the fourth comma in line (r).
Step 4. Find, starting at position q, the decimal point symbol (t).
Step 5. Extract one character from the string at position (r + 1).
Step 6. If this character is equal to W, then the NorthernHemisphere variable gets the value 1, otherwise -1.
Step 7. Extract (r— + 2) characters of the string, starting at position (t-2).
Step 8. Extract (t-q-3) characters from the string starting at position (q + 1).
Step 9. Convert strings to real numbers and calculate the Y coordinate of the object in radian measure.
Determining the X coordinate of an object
Step 10. Find the position of the fifth comma in line (n).
Step 11. Find the position of the sixth comma in line (m).
Step 12. Find, starting at position n, the decimal point character (p).
Step 13. Extract one character from the string at position (m + 1).
Step 14. If this character is "E", then the EasternHemisphere variable gets the value 1, otherwise -1.
Step 15. Extract (m-p + 2) characters from the string starting at position (p-2).
Step 16. Extract (p-n + 2) characters from the string starting at position (n + 1).
Step 17. Convert strings to real numbers and calculate the X coordinate of the object in radian measure.
Step 18. If the NMEA file is not read to the end, go to step 1, otherwise go to step 19.
Step 19. Finish the algorithm.
In steps 6 and 16 of this algorithm, the NorthernHemisphere and EasternHemisphere variables are used to numerically encode the location of the object on Earth. In the northern (southern) hemisphere, the NorthernHemisphere variable takes the value 1 (-1), respectively, similarly in the eastern EasternHemisphere - 1 (-1).
GIS application
The use of geographic information systems is widespread in many areas:
- geology and cartography;
- trade and services;
- cadastre;
- economics and management;
- defense;
- engineering;
- education, etc.
