Geography & Technology Geography of Canada www.craigmarlatt.com/school
Geography & Technology 1. Geographic Informationn Systems 2. Global Positioning System 3. Aerial Photographs 4. Satellite Imagery
Geographic Information Systems Geographic Information Systems (GIS) is a technology that manages, analyzes, and disseminates geographic knowledge. Essentially, GIS is maps on computers. Each characteristic of the Earth s surface is mapped on a layer which can be viewed independently, or in combination with other layers.
Geographic Information Systems
Geographic Information Systems There are three ways of viewing a GIS: a database, map, and model. The Database View: A GIS is a unique kind of database of the world a geographic database (geodatabase). It is an "Information System for Geography." Fundamentally, a GIS is based on a structured database that describes the world in geographic terms.
Geographic Information Systems GIS can analyze data in many ways:
Geographic Information Systems The Map View: A GIS is a set of intelligent maps and other views that show features and feature relationships on the earth's surface. Maps of the underlying geographic information can be constructed and used as "windows into the database" to support queries, analysis, and editing of the information. This is called geovisualization.
Geographic Information Systems The Model View: A GIS is a set of information transformation tools that derive new geographic datasets from existing datasets. These geoprocessing functions take information from existing datasets, apply analytic functions, and write results into new derivedd datasets.
GIS Locations and Attributes Location Information: Where is it? 51 N, 112 W Attribute Information: What is it? Species: Oak Height: 15m Age: 75 Yrs Source: ESRI Canada, WhatsGIS.ppt
GIS Locations and Attributes GIS software links the location data and the attribute data: Source: ESRI Canada, What s GIS.ppt
GIS Asking Questions GIS software can answer questions about our world: Spatial Questions: What provinces border Saskatchewan? Attribute Questions: What provinces have more than 1.5 million people? Source: ESRI Canada, What s GIS.ppt
GIS Why Use It? Support for decision-making based on spatial data: Visual representationn of data Maintenance, manipulation of data Analyze information and the affected area(s) geographically Produce customized cartographic products
GIS Real World Uses Management Agriculture Public Utilities Health Care Emergency 911 Real Estate Marketing
GIS Real World Uses What are the effects of Global Warming? Land cover and temperature relationships are made clear when the data are seen at once using Geotechnology.
GIS Real World Uses Is it safe to dig here? A proposed excavation, identifiedd by address, is compared to pipelines in the area using Geotechnology. Source: ESRI Canada, What s GIS.ppt
GIS Real World Uses What is the fastest route to the Hospital? Geotechnology can choose the fastest route to a hospital. The GIS can take into account traffic and other impediments. Source: ESRI Canada, What s GIS.ppt
GIS Real World Uses What Communities are at risk from Disease? Geotechnology identifies communities at risk of River Blindness and helps determine the impact of treatment t. Source: ESRI Canada, What s GIS.ppt
Global Positioning System The GPS (Global Positioning System) is a "constellation" of 24 well-spaced satellites that orbit the Earth and make it possible for people with ground receivers to pinpoint their geographic location. The location accuracy is anywhere from 100 to 10 metres for most equipment. Accuracy can be pinpointed to within one metre with special military-approved equipment.
Global Positioning System GPS equipment is widely used in science and has now become sufficiently low-cost so that almost anyone can own a GPS receiver. The GPS is owned and operated by the U.S. Department of Defense but is available for general use around the world.
Global Positioning System
Global Positioning System A hand-held GPS unit
Global Positioning System An in-dash GPS unit
Aerial Photographs Using the photographs of the Earth taken by airplanes, you can see the world in 3D using a stereoscope.
Aerial Photographs Google Earth is a computer program (that you can download for free!) that shows aerial photographs in a digital format, with a general purpose map on top. www.earth.google.com
Satellite Imagery Satellite images are also pictures of the Earth taken from above, but these electronic images (instead of photographs) cover very large areas but show less detail. Landsat was developed by the Americans and uses sunlight and heat reflected from the Earth s surface to create images SPOT was developed by the Europeans and similar to Landsat, but it can createe 3D images of the surface RADARSAT was developed by the Canadians and uses radar signals (or microwaves) instead of sunlight and heat, so it can be used at any time of day or night