Introduction to Geographic Information System Qian Yu Department

Introduction to Geographic Information System Qian Yu Department of Geosciences

Outline n n n n What is GIS? GIS data format Understanding scale Global Positioning System GIS application Mass. GIS data viewer Google Earth

Digitizing Our World n Two types of information: Location ¨ Attribute ¨ Location Information: Where is it? Attribute Information: What is it? Species: Oak Height: 15 m Age: 75 Yrs 51°N, 112°W After: ESRI, 2001

What is GIS? n GI System: ¨A GIS is an immensely powerful computer mapping and analysis system. ¨ It links geographic locations with information about them so you can create maps and analyze information in new ways. ¨ Techniques for acquisition, storage, manipulation, analysis, and display of spatial data. n GI Science: research with GIS (Applied Science)

Subsystems of GIS ¨ Input System n digitizing, scanning, GPS ¨ Database Management System ¨ Geographic Analysis System ¨ Output System GIS Abstraction or Simplification Software Tools + The real world Results Database

GIS data format - Geographic Data Representation Raster Vector 1 2 3 4 5 6 7 8 9 10 3 1 2 2 1 2 1 2 4 Poly 1 400 3 1 Line 1 500 Y-Axis 1 2 3 4 5 6 7 8 9 10 1 300 Poly 2 200 Pt 1 Point Line 1 1 Polygon 100 1 1 - River 2 - Pine 3 - Fir 4 - House 100 Pt 1 Line 1 Poly 2 200 300 X-Axis Building House Fir Pine 400 5 00 Owner Length Area … …

Scale n Scale: the ratio of the distance on a map to that on the ground between the same two points, in the same units. n Three way to express the scale of a map ¨ Representative ¨ Statement ¨ Bar scale fraction 1: 1, 000 One millimeter to one kilometer scale n Larger scale (ratio) maps show more detail. n GIS data can be displayed at any scale, but GIS data should not be displayed beyond the accuracy at which the data was developed.

1: 250, 000 smaller scale 1: 24, 000 larger scale 1: 62, 500 1: 24, 000 More detail 1: 100, 000 mid-scale 1: 250, 000

Global Positioning System n GPS a global satellite based radio -navigation system/technology, consisting of 24 orbiting satellites at an altitude of 20, 000 km in space, in six different orbital paths/plane and their ground stations. n 12 hours return interval for each satellite (2 complete orbits around the Earth in less than 24 hours). n Functioning satellite GPS systems NAVSTAR

GPS components n Satellite segment n Control segment Tracking, communications, data gathering, integration, analysis… n User segment GPS receivers

Why is GIS important? Overlay visualization or modeling ¨ Map production ¨ Integration data sources ¨ Spatial analysis and modeling ¨ Exploration and prediction

GIS Application n n Daily life Cartography Environmental management 3 D visualization Modeling The application of GIS is limited only by the imagination of those who use it. - Jack Dangermond

3 -D Topography Pioneer Valley

Our daily life need GIS Driving direction GIS for showing where you are and the best route from A to B Locating a store GIS for mapping shops near you

Combing Data From Many Sources

3 -D Display View large data sets seamlessly 3 D mine with well data 3 D urban 3 -D Virtual Model for Urban Planning

Hydrodynamic Modeling: Downstream Flooding Sacramento, California, USA (From: U. S. Bureau of Reclamation)

GIS Data in Mass. GIS n Base Map Data ¨ Vector (point/line/area) n n ¨ In shape file or coverage Raster (image data) n n n Features such as roads, streams, and political boundaries --relatively permanent, widely used features. Black & White Digital Orthophotos, Scanned USGS Quads, and Coastal Color Orthophotos, Available in Tiff and Mr. SID formats. Environmental Data ¨ Developed, maintained and updated by EOEA and its agencies for the purpose of enforcing environmental regulations or in support of various types of environmental analysis.

Mass. GIS Runtime Data Viewer n Stand-alone, "light, " or scaled-down version of Arc. View GIS 3. 1. 1 n With much of the map-making functionality n Function: ¨ Display all the Mass. GIS data ¨ Change symbolization of the data and add annotation to the map ¨ Create a map layout with map elements such as a scale bar, north arrow, legend and title ¨ Conduct data query and analysis

Google Earth n Client software of web GIS service. ¨ n The planet's imagery and other geographic information are put on server and your computer retrieves data through internet real -time. Function: Fly from space to your neighborhood. Type in an address and zoom right in. ¨ Search for schools, parks, restaurants, and hotels. Get driving directions. ¨ Tilt and rotate the view to see 3 D terrain and buildings. ¨ Save and share your searches and favorites. Even add your own annotations. ¨