MapWindow

MapWindow is an open source "Programmable Geographic Information System" that supports manipulation, analysis, and viewing of geospatial data and associated attribute data in several standard GIS data formats.

MapWindow is a
mapping tool, a GIS modeling system and a GIS application programming interface (API) all in one convenient redistributable open source solution.

The MapWindow application is a free, extensible geographic information system (GIS) that can be in many ways:

• As an open-source alternative desktop GIS
• To distribute data to others
• To develop and distribute custom spatial data analysis tools

MapWindow (Features)

• As an open-source tool, MapWindow is free to use and redistribute to the user clients and other end users. It may also be modified to fit the user needs, or embedded into proprietary software.
• MapWindow is more than just a data viewer. It is an extensible geographic information system. This means that advanced users or developers can write plugins to add additional functionality (models, special viewers, hot-link handlers, data editors, etc.) and pass these along to any number of the user's clients and end users.
• MapWindow includes standard GIS data visualization features as well as DBF attribute table editing, shapefile editing, and data converters. Dozens of standard GIS formats are supported, including Shapefile, GeoTIFF, ESRI ArcInfo ASCII and binary grids.
• MapWindow also includes a complete ActiveX component which may be used to instantly add GIS capabilities to the user's existing software product. Additional geoprocessing components are available. NET-compatible languages.

Geographical Information System(GI)

1. GIS: A type of software

• A computer systems that allows us to handle information about the location of features or phenomena on the Earth's surface
• Has all the functionality of a conventional DBMS plus much of the functionality of a computer mapping system
• GIS as a DBMS that allows us to explicitly handle the spatial
• Common examples:

                ArcGIS

                MapInfo

2. GIS: A tool - kit

         Manipulate spatially:

                 Calculate distances and adjacencies

                 Change projections and scales

                  Integrate disparate sources

         Analyse spatially:

                  Quantitative analysis

                   Exploratory spatial data analysis

                   Qualitative analysis

         Visualize data:

                    Maps!

                    Tables, graphs, etc.

                    Animations

                    Virtual landscapes

3. Approach:

    Explore the database:

          In conventional ways

          AND geographically

• Allows us to think about the implications of location
• Allows us to think holistically
• Should not be restricted by vendor - provided functionality
• Should be used imaginatively taking into account

              - the advantages and limitations of geographical information

              - the traditions of humanities scholarship

Geographical Information Technologies

• Global Positioning System (GPS)

               a system of earth - orbiting satellites which can provide precise (100 meter to sub - cm.) location on                                   the earth's surface (in lat/long coordinates or equiv.)

• Remote Sensing (RS)

                use of satellites or aircraft to capture information about the earth's surface

                Digital ortho images a key product (map accurate digital photos)

• Geographic Information System (GIS)

                 Software systems with capability for input, storage manipulation/analysis and output/display of geographic (spatial) information

GPS and RS are sources of input data for a GIS

A GIS provides for storing and manipulating GPS and RS data.

Geographical Information System:(intuitive description)

• A map with a database behind it
• A virtual representation of the real world and its infrastructure
• A consistent "as - built" of the real world natural and manmade

Which is

• queried ti support on - going operation
• summarized to support strategic decision making and policy formulation
• analyzed to support scientific inquiry

How GIS differs from Related Systems

• DBMS - typical MIS database contains implicit but not explicit locational information

- city, country, zip code, etc. but no geographical coordinates

- is 100 N. High around the corner or across town from 200 E Main?

• Automated Mapping (AM) - primary to dimensional display davice

- thematic mapping (choropleth, etc such as SAS/GRAPH, DIDS, business mapping software) unable to relate different geographical layers (e.g zip codes and countries)

- automated cartography - graphical design oriented; limited database ability

• Facility Management (FM) System - lack spatial analysis tools
• CAD/CAM (computer aid design/drafting) - primarily 3 - D graphic creation (engineering design) and display systems

- don't reference via geographic location

- limited (if any) database ability (especially for non-spatial data)

• Graphic Software (Photoshop, Corel Draw) - sophisticated multi - dimensional graphics, but:

- lack database support

- lack two -  dimensional spatial analysis tools

GIS Data Type

Two types of data are stored for each item in the database

1. Attribute data:

               Says what a feature is 

                       Eg. statistic, text, images, sound, etc.

     2. Spatial data:

                Says where the feature is

                Co-ordinate based

                Vector data - discrete features:

                         Points

                         Lines

                         Polygons (zones or areas)

                 Raster data:

                         A continuous surface

Why study GIS?

• 80% of local government activities estimated to be geographically based

- plats, zoning public works (streets, water supply, sewers), garbage collection, land ownership and valuation, public safety (fire and police)

• A significant portion of state government has a geographical component

- natural resources management

- highways and transportation

• Businesses use GIS for a very wide array of applications

- retail site selection & customer analysis

- logistics: vehicle tracking & routing

- natural resources exploration (petroleum, etc.)

- precision agriculture

-civil engineering and construction

• Military and Defense

- Battlefield management

- Satellite imagery interpretation

• Scientific research employs GIS

- geography, geology, botany

- anthropology, sociology, economics, political science

-epidemiology, criminology

Examples of Applied GIS

Urban planning, Management & Policy

• Zonning, subdivision, planning
• Land acquisition
• Economic development
• Code enforcement
• Housing renovation programs
• Emergency response
• Crime analysis
• Tax assessment

Environment Sciences

• Monitoring environment risk
• Modeling storm water run off
• Management of water sheds, floodplains, wetlands, forests, aquifers
• Environmental Impact Analysis
• Hazardous or toxic facility siting
• Ground water modeling and contamination tracking

Political Science

• Redistricting
• Analysis of election result
• Predictive modeling

Civil Engineering/Utility

• Locating underground facilities
• Designing alignment for freeways, transit
• Coordination of infrastructure maintenance

Business

• Demographic Analysis
• Market Penetration/Share Analysis
• Site Selection

Education Administration

• Attendance Area Maintenance
• Enrollment Projections
• School Bus Routing

Health Care

• Epidemiology
• Needs Analysis
• Service Inventory

What is GIS Application DO:(manage, analyze, communication)

- make possible the automation of activities involving geographic data

• map production
• calculation of areas, distances, routes lengths
• measurement of slope, aspect, view shed
• logistics: route planning, vehicle tracking, traffic management

- allow for the integration of data hitherto confined to independent domains (e.g property maps and air photos)

- by tieing data to maps, permits the succinct communication of complex spatial patterns ( e.g environmental sensitivity)

- provides answer to spatial queries

- perform complex spatial modeling (what if scenarios for transportation planning, disaster planning, resource management, utility design)

Spatial and Attribute Data

Spatial data (where)

• specifies location
• stored in a shape file, geodatabase or similar geographic file

Attribute (descriptive) data (what, how much, when)

• specifies characteristics at that location, natural or human created
• stored in a data base table

GIS traditionally maintain spatial and attribute data separately, then "join' them for display or analysis

• for example, in Mapview, the Attributes of...table is used to link a shapefile (spatial structure) with a data base table containing attribute information in order to display the attribute data spatially on map.

Representing Data with Raster and Vector Mode

Raster Model

• Area is covered by grid with (usually) equal - sized, square cells
• Attributes are recorded by assigning each cell a single value based on the majority featured (attribute) in the cell, such as land use type.
• Image data is a special case of raster data in which the "attribute" is a reflectance value from the geomagnetic spectrum

                           - cells in image data often called pixels (picture elements)

Vector Model

The fundamental concept of vector GIS is that all geographic features in the real work can be represented either as:

• points or dots (nodes): trees, poles, fire plugs, airports, cities
• lines (arcs): streams, streets, sewers
• areas (polygons): land parcels, cities, countries, forest, rock type

Because representation depends on shape, Mapview refers ro files containing vector as shapefiles

Projection, Scale, Accuracy and Resolution (the key properties of spatial data))

Projection: the method by which the curved 3-D surface of the earth is represented by X,Y coordinates on a 2-D flat map/screen

• distortion is inevitable

Scale: the ratio of distance on a map to the equivalent distance on the ground

• in theory GIS is scale independent but in practice there is an implicit range of scales for data output in any project

Accuracy: how well does the database info match  the real world

• Positional: how close are features to their real world location
• Consistency: do feature characteristics in database match those in real world

                               is  a road in the database a road in the real world?

• Completeness: are all real world instances of features present in the database?

                                 Are all roads included.

Resolution: the size of the smallest feature able to be recognized

                            for raster data, it is the pixel size

Basic of Map Projections

• A map projection is a mathematical model for conversion  of location from a three-dimensional earth surface to a two-dimensional map representation. This conversion necessarily distorts some aspect of the earth's surface, such as area, shape, distance, or direction.
• Projection make it possible to create maps of areas of the earth with as little distortion as possible. The projection process affects four properties: area, shape, distance and direction. There is no projection that maintains the integrity of all four properties at the same time.
• There are thousands of different map projections all depending on how they intersect earth's surface and how they are oriented. For example the line of latitude or longitude where a projection intersects or "cuts" the earth's surface is called the point of contact, or standard line, where distortion is minimized.

Common GIS Projections

• Mercator -  A conformal, cylindrical projection tangent to the equator. Originally created to display accurate compass bearings for sea travel. An additional feature of this projection is that all local shapes are accurate and clearly defined.
• Transverse Mercator - Similar to the Mercator except that the cylinder is tangent along a meridian instead of the equator. The result is a conformal projection that minimizes distortion along a north - south line, but does not maintain true directions.
• Universal Transverse Mercator(UTM) - Based on a Transverse Mercator projection centered in the middle of zones that are 6 degrees in longitude wide. These zones have been created throughout the world.
• Albers Equal Area Conic -  This conic projection uses two standard parallels to reduce some of the distortion of a projection with one standard parallel. Shape and linear scale distortion are minimized between standard parallels.

Coordinate System

• There are many different coordinate systems, based on a variety of geodetic datums, projections, and units use
• Geographic coordinate systems (no projection): Spheriod (or Ellipsoid) - based systems, local systems.
• Projected coordinate systems: world, continental, polar, US National Grids, UTM, state plane.

Coordinate System vs. Map Projections

• A map projection is a method  or a type of equation used to transform three-dimensional coordinates on the earth to two-dimensional coordinates on the map.
• A coordinate system usually includes the specification of a map projection, plus the three dimensional model of the Earth to be used, the distance units to be used on the map, and information about the relative positions of the two dimensional map and the model of the Earth.

ESRI

A geographic coordinate system is a coordinate system that enables every location on the Earth to be specified by a set of numbers. The coordinates are often chosen such that one of the numbers represent vertical position, and two or three of the numbers represent horizontal position. A common choice of coordinates is latitude, longitude and elevation.

Example of Coordinates System

2 Type of Coordinate System

• Geographic Coordinate System (GCS)
• Projected Coordinate System

WGS_1984_UTM_Zone_51N                                GCS_PRS_1992

Projection: Transverse_Mercator                              Datum:

False_Easting: 500000.000000                                 D_Philippine_Reference_System_1992

False_Northing: 0.000000

Cental_Meridian: 123.000000

Scale_Factor: 0.999600

Latitude_Of_Origin: 0.000000

Linear Unit: Meter

GCS_WGS_1984

Datum: D_WGS_1984

GIS Data Model

• Allows the geographic features in real world locations to be digitally represented and stored in a database so that they can be abstractly presented in map (analog) form, and can also  be worked with and manipulated to address some problem.

Geographical Information (GI)

Information that refers to location on the Earth's surface has both spatial and a thematic component

Census data
Hospitals admissions data
Relief data(e.g, from contours)
Information on transport networks
A text about a specific place (e.g, Defoe's description of London during the Plague)
A photograph or painting of a building

Locational component can be an explicit (e.g, a co-ordinate or a precisely defined administrative unit) or vaguer (e.g, "The area around Philippines" or "in Filipino speaking areas")

Geographical/Geospatial Information

information about places on the earth's surface knowledge about "what is where when"


GIS - what's in the S?


Systems: the technology
Science: the concepts and theory
Studies: the societal context

Welcome to the MapWindow GIS Open Source Project

The MapWindow GIS project includes a free and open source desktop geographic information system (GIS) with an extensible plugin architecture; a GIS ActiveX control; and C# GIS programmer library called DotSpatial. We would be happy to have you join our project. Feel free to browse this site, or follow the links below depending on if you are a GIS user, GIS programmer, or potential project contributor.