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Maps and the Geospatial Revolution: Lesson 3, Lecture 1


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These are the slides to accompany the first lecture from Lesson 3 of Maps and the Geospatial Revolution on Coursera.

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Maps and the Geospatial Revolution: Lesson 3, Lecture 1

  1. 1. Maps and the Geospatial RevolutionLesson 3 – Lecture 1Anthony C. Robinson, Ph.DLead Faculty for Online Geospatial EducationJohn A. Dutton e-Education InstituteAssistant Director, GeoVISTA CenterDepartment of GeographyThe Pennsylvania State UniversityThis content is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License
  2. 2. Where are we now?• Locating things used to be very difficult, and it was done usingtime-intensive methods that weren’t very accurate• You probably associate location technology with GPS –– Global Positioning System, built by the U.S. military starting in the1970’s– Not invented by Apple or Google, believe it or not• GPS is one example of a Global Navigation Satellite System(GNSS)– Others include the Russian GLONASS and EU Galileo system
  3. 3. Where are we now?• It’s already common for consumer devices to useGNSS to derive locations– Often augmented with wifi hotspots and other signalsthat combined can improve accuracy and coverage• Consumer-grade stuff can locate positions to withina few meters, but they can be off by hundreds ofmeters in poor conditions• Professional systems are used for surveyingproperty lines and other serious geo-tasks
  4. 4. Where are we now?• A GPS-enabled device can give you a point location defined bylatitude and longitude coordinates– My desk at home is 40.77004, 77.896744• If I walked around my yard collecting multiple points, I couldcreate a polygon that represents the property I own• If I collected points in a row between my couch and the fridge,I’d have a line feature• Points, lines, and polygons are the primary forms of spatialvector data
  5. 5. The Earth from Above• Virtual globe tools like Google Earth havemade images of the Earth easily accessible• Most geographic image data comes fromsatellites and airborne sensors, but you caneven make your own DIY Drone now• Geographic image data is raster data, whichcaptures information by assigning values tocells in a grid
  6. 6. The Earth from Above• The size of raster grid cells determines howmuch resolution you have for the image
  7. 7. The Earth from Above• The science and technology associated withimaging the Earth is called Remote Sensing• It’s not just photographs – it can involve theuse of lasers (LIDAR) and infrared sensors
  8. 8. The Earth from AboveSource: Science@NASA:
  9. 9. Source: USGS:
  10. 10. Source: USGS:
  11. 11. Maps and the Geospatial Revolution @MapRevolutionOnline Geospatial Education @ Penn State www.pennstategis.comThis content is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License