Geographic information system (GIS) is a computer-based tool for mapping and analyzing things that exist and events that happen on earth. GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps. These abilities distinguish GIS from other information systems and make it valuable to a wide range of public and private enterprises for explaining events, predicting outcomes, and planning strategies

Our GIS service offerings include

Data Capture from Topographical, Thematic Maps, contour etc maps Digitization of city Atlas, Regional maps, Geological maps Parcel Mapping Digital conversion of weather maps Digital conversion Well logging data, survey maps etc Cross-platform migration & maintenance of Geospatial data Digital Photogrammetry, feature collector from arial photos. Data capture for map publishing industry Geo-referencing and rectification of maps DTM Creation from elevation data and generation of Longitudinal and Transverse profiles.

• Components of a GIS
  A working GIS integrates five key components: hardware, software, data, people, and methods.
  
  A successful GIS operates according to a well-designed plan and business rules, which are the models and operating practices unique to each organization.
  
  
  

• How GIS Works

  A GIS stores information about the world as a collection of thematic layers that can be linked together by geography. This simple but extremely powerful and versatile concept has proven invaluable for solving many real-world problems from tracking delivery vehicles, to recording details of planning applications, to modeling global atmospheric circulation.

  
  Vector and Raster Models
  Geographic information systems work with two fundamentally different types of geographic models--the "vector" model and the "raster" model. In the vector model, information about points, lines, and polygons is encoded and stored as a collection of x,y coordinates. The location of a point feature, such as a bore hole, can be described by a single x,y coordinate. Linear features, such as roads and rivers, can be stored as a collection of point coordinates. Polygonal features, such as sales territories and river catchments, can be stored as a closed loop of coordinates. The vector model is extremely useful for describing discrete features, but less useful for describing continuously varying features such as soil type or accessibility costs for hospitals. The raster model has evolved to model such continuous features. A raster image comprises a collection of grid cells rather like a scanned map or picture. Both the vector and raster models for storing geographic data have unique advantages and disadvantages. Modern GIS are able to handle both models.

• What GIS can do

  General purpose geographic information systems essentially perform five processes or tasks:

  • Input
  • Manipulation
  • Management
  • Query and Analysis
  • Visualization
    
    

  Input
  Before geographic data can be used in a GIS, the data must be converted into a suitable digital format. The process of converting data from paper maps into computer files is called digitizing.
  Modern GIS technology can automate this process fully for large projects using scanning technology; smaller jobs may require some manual digitizing (using a digitizing table). Today many types of geographic data already exist in GIS-compatible formats. These data can be obtained from data suppliers and loaded directly into a GIS.

  Manipulation
  It is likely that data types required for a particular GIS project will need to be transformed or manipulated in some way to make them compatible with your system. For example, geographic information is available at different scales (detailed street centerline files; less detailed census boundaries; and postal codes at a regional level). Before this information can be integrated, it must be transformed to the same scale (degree of detail or accuracy). This could be a temporary transformation for display purposes or a permanent one required for analysis. GIS technology offers many tools for manipulating spatial data and for weeding out unnecessary data.

  Management
  For small GIS projects it may be sufficient to store geographic information as simple files. However, when data volumes become large and the number of data users becomes more than a few, it is often best to use a database management system (DBMS) to help store, organize, and manage data.A DBMS is nothing more than computer software for managing a database.
  There are many different designs of DBMSs, but in GIS the relational design has been the most useful. In the relational design, data are stored conceptually as a collection of tables. Common fields in different tables are used to link them together. This surprisingly simple design has been so widely used primarily because of its flexibility and very wide deployment in applications both within and without GIS.

  Query and Analysis
  Once you have a functioning GIS containing your geographic information, you can begin to ask simple questions such as

  • Who owns the land parcel on the corner?
  • How far is it between two places?
  • Where is land zoned for industrial use?

  
  And analytical questions such as

  • Where are all the sites suitable for building new houses?
  • What is the dominant soil type for oak forest?
  • If I build a new highway here, how will traffic be affected?

GIS provides both simple point-and-click query capabilities and sophisticated analysis tools to provide timely information to managers and analysts alike. GIS technology really comes into its own when used to analyze geographic data to look for patterns and trends and to undertake "what if" scenarios. Modern GIS have many powerful analytical tools, but two are especially important.

Proximity Analysis

• How many houses lie within 100 m of this water main?
• What is the total number of customers within 10 km of this store?
• What proportion of the alfalfa crop is within 500 m of the well?

To answer such questions, GIS technology uses a process called buffering to determine the proximity relationship between features.

Overlay Analysis
The integration of different data layers involves a process called overlay. At its simplest, this could be a visual operation, but analytical operations require one or more data layers to be joined physically. This overlay, or spatial join, can integrate data on soils, slope, and vegetation, or land ownership with tax assessment.

Visualization
For many types of geographic operation the end result is best visualized as a map or graph. Maps are very efficient at storing and communicating geographic information. While cartographers have created maps for millennia, GIS provides new and exciting tools to extend the art and science of cartography. Map displays can be integrated with reports, three-dimensional views, photographic images, and other output such as multimedia.

• How GIS help

  Perform Geographic Queries and Analysis
  The ability of GIS to search databases and perform geographic queries has saved many companies literally millions of dollars. GIS have helped reduce costs by

  • Streamlining customer service.
  • Reducing land acquisition costs through better analysis.
  • Reducing fleet maintenance costs through better logistics.
  • Analyzing data quickly, as in this example:

A realtor could use a GIS to find all houses within a certain area that have tiled roofs and five bedrooms, then list their characteristics

The query could be further refined by adding criteria - the house must cost less than $100 per square foot. You could also list houses within a certain distance of a school.

Improve Organizational Integration
Many organizations that have implemented a GIS have found that one of its main benefits is improved management of their own organization and resources. Because GIS have the ability to link data sets together by geography, they facilitate interdepartmental information sharing and communication. By creating a shared database, one department can benefit from the work of another - data can be collected once and used many times.

As communication increases among individuals and departments, redundancy is reduced, productivity is enhanced, and overall organizational efficiency is improved. Thus, in a utility company the customer and infrastructure databases can be integrated so that when there is planned maintenance, affected customers can be sent a computer-generated letter.

Make Better Decisions
The old adage "better information leads to better decisions" is as true for GIS as it is for other information systems. A GIS, however, is not an automated decision making system but a tool to query, analyze, and map data in support of the decision making process. GIS technology has been used to assist in tasks such as presenting information at planning inquiries, helping resolve territorial disputes, and siting pylons in such a way as to minimize visual intrusion.
GIS can be used to help reach a decision about the location of a new housing development that has minimal environmental impact, is located in a low-risk area, and is close to a population center. The information can be presented succinctly and clearly in the form of a map and accompanying report, allowing decision makers to focus on the real issues rather than trying to understand the data. Because GIS products can be produced quickly, multiple scenarios can be evaluated efficiently and effectively.