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What is a GIS? + Information System A means of storing,

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Presentation on theme: "What is a GIS? + Information System A means of storing,"— Presentation transcript:

1 What is a GIS? + Information System A means of storing,
retrieving, sorting, and comparing spatial data to support some analytic process. + Geographic Position A GIS can be best defined by defining the two parts of the term; geography and information system. Geography is a science that deals with the earth and life on the earth, while an information system is a way to capture, store, retrieve, sort, and process data to support some analytic process.

2 What is a GIS? GEOGRAPHIC Information System
What makes the Information System geographic? The user needs to begin spatially! GIS links graphical features (entities) to tabular data (attributes)

3 GIS Definition A GIS is a system(hardware + database engine) that is designed to efficiently, assemble, store, update, analyze, manipulate, and display geographically referenced information (data identified by their locations). A GIS also includes the people operating the system and the data that go into the system. A 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, military and private enterprises for explaining events, predicting outcomes, and planning strategies. Whether siting a military base camp, finding the best soil for a tank to maneuver on, or figuring out the best low level air route for a bombing raid. Map making and geographic analysis are not new, but a GIS performs these tasks better and faster than do the old manual methods. And, before GIS technology, only a few people had the skills necessary to use geographic information to help with decision making and problem solving. Today, GIS is a multi-billion-dollar industry employing hundreds of thousands of people worldwide. GIS is taught in schools, colleges, and universities throughout the world. Professionals in every field are increasingly aware of the advantages of thinking and working geographically.

4 GIS

5 Key Functions of a GIS Data can be:
Positioned by its known spatial coordinates. Input and organized (generally in layers). Stored and retrieved. Analyzed (usually via a Relational DBMS). Modified and displayed A 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, military and private enterprises for explaining events, predicting outcomes, and planning strategies. Whether siting a military base camp, finding the best soil for a tank to maneuver on, or figuring out the best low level air route for a bombing raid. Map making and geographic analysis are not new, but a GIS performs these tasks better and faster than do the old manual methods. And, before GIS technology, only a few people had the skills necessary to use geographic information to help with decision making and problem solving. Today, GIS is a multi-billion-dollar industry employing hundreds of thousands of people worldwide. GIS is taught in schools, colleges, and universities throughout the world. Professionals in every field are increasingly aware of the advantages of thinking and working geographically.

6 Commponent of GIS

7 GIS Data layers

8 Geographic Information Systems
Decision GIS Process Output GIS analysis Import or build datasets Define GIS criteria Define problem Define problem Decision GIS Process Define GIS criteria Output GIS PROCESS: The GIS process involves six steps that are common to what we refer to as the end to end map-making process. 1. Define the spatial problem/question. .Define the GIS criteria. .Import or create the data sets .Perform the GIS analysis .Create the output .Decide whether or not the output solves or answers the spatial problem/question. If not, then refine the problem and start the process again. GIS analysis Import or build datasets

9 Representing Spatial Elements
RASTER VECTOR Real World Spatial data is essentially data with a location. It contains information about the location and shape of, and relationship among geographic features usually stored as coordinates. Spatial data comes in two types, VECTOR and RASTER. Geographic information systems work with two fundamentally different types of geographic models--the "vector model" and the "raster model."

10 Raster vs. Vector Raster Advantages Vector Advantages
The most common data format Easy to perform mathematical and overlay operations Satellite information is easily incorporated Better represents “continuous”- type data Vector Advantages In Raster we explicitly store attribute information and imply its location based on the position within the grid cell structure. In Vector, we explicitly store the entity information and where the entity is located. We rely on a database structure to link to attribute information. Accurate positional information that is best for storing discrete thematic features (e.g., roads, shorelines, sea-bed features. Compact data storage requirements Can associate unlimited numbers of attributes with specific features

11 GIS Functions Data Assembly Data Storage
Spatial Data Analysis and Manipulation Spatial Data Output

12 GIS Functions Data Assembly Manual Digitizing Manual Digitizing
Scanning Manual Digitizing Scanning RSI Maps Intel Database Data Transfer Data Transfer I n p u t: 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. NIMA standard digital data exists in useable formats and can usually be loaded directly into a GIS. Direct Entry GPS Keyboard

13 Data Input/Creation This slide demonstrates heads-up digitizing done in ArcView.

14 GIS Functions Spatial data Attribute data GIS Storage
1 (Universe polygon) Spatial data 2 3 3 (ARC functions) 4 5 Storage: For small GIS projects it may be sufficient to store geographic information as simple files. There comes a point, however, when data volumes become large and the number of data users becomes more than a few, that it is best to use a database There are many different designs of DBMSs, but in GIS the relational design has been the most useful. A DBMS is nothing more than computer software for managing a database--an integrated collection of data. 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. COV# ZONE ZIP 1 2 C-19 22060 Attribute data 3 A-4 22061 3 A-4 22061 4 C-22 22060 (INFO or TABLES functions) 5 A-5 22057

15 GIS Functions Spatial Data Manipulation and Analysis
Common Manipulation Reclassification Map Projection changes Common Analysis Buffering Overlay Network Analysis and M a n i p u l a t i o n: 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 (street centerline files might be available at a scale of 1:100,000; Topographic line maps data such as ITD at 1:50,000). Before this information can be integrated, it must be transformed to the same scale. 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.

16 Spatial Analysis Overlay function creates new “layers” to solve spatial problems The overlay operation is one the most powerful functions in a GIS. It gives the user the ability to place the cartographic representation of thematic data over one another. However, this is hardly a new function developed by a GIS, but it has been revolutionized by the use of the computerized GIS.

17 GIS Functions Spatial Data Output Tables Maps Interactive Displays
3-D Perspective View There are many forms of output for a GIS. The first is usually softcopy, namely what you see on the screen. Most Military service member and commanders prefer to have something hardcopy. So more often than not, will require hard copy outputs. A full functioning GIS can do this. It can plot/print given the equipment, the 2D and 3D perspective views on a 2D map.

18 GIS Applications Site selection Helicopter Landing Zones
Amphibious Assault (Water Depth) Buffer Zones Flight Planning Battlefield Visualisation Talk to each one relevant to the audience.

19 Spatial Analysis Proximity Analysis (Buffers)
1000 Meter Buffer of Railroads This slide shows a proximity analysis of railroads around the Tuzla airport in Bosnia. The buffer is 1000 meters and the areas in blue represent all areas within this 1000 meter range. CAUTION: DO NOT Make assumptions based on visual correspondence only. The user must obtain evidence on a true cause and effect relationship.

20 Flight Planning This slide shows an example of flight planning within ArcView through the use of Elevation and Cloud cover data.

21 Flight Planning/Flythroughs

22 Battlefield Visualization and/or Situation Awareness

23 Other GIS Applications
Cross country movement Route planning Intervisibility study Facilities management Airfield assessment Road network analysis (convoys) Propagation coverages Observation post siting analysis Perspective views

24 Network Analysis The slide shows a Network model, which gives the best route given certain criteria. The green squares denote bridges, which can serve as a limitations within the model. For example, if a bridge was impassible, we could factor that criteria into our model and the route could be recalculated giving us a different solution.

25 Perspective Views This slide shows a perspective view. A LANDSAT image has been draped over DTED and the buildings have been overlaid over the image and “grown” to represent a 3D view.

26 EXAMPLE OF GIS


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