These are the slides to accompany the first lecture from Lesson 3 of Maps and the Geospatial Revolution on Coursera. www.coursera.org/course/maps/

1. Maps and the Geospatial Revolution
Lesson 3 – Lecture 1
Anthony C. Robinson, Ph.D
Lead Faculty for Online Geospatial Education
John A. Dutton e-Education Institute
Assistant Director, GeoVISTA Center
Department of Geography
The Pennsylvania State University
This content is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License

2. Where are we now?
• Locating things used to be very difficult, and it was done using
time-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 the
1970’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. Where are we now?
• It’s already common for consumer devices to use
GNSS to derive locations
– Often augmented with wifi hotspots and other signals
that combined can improve accuracy and coverage
• Consumer-grade stuff can locate positions to within
a few meters, but they can be off by hundreds of
meters in poor conditions
• Professional systems are used for surveying
property lines and other serious geo-tasks

4. Where are we now?
• A GPS-enabled device can give you a point location defined by
latitude and longitude coordinates
– My desk at home is 40.77004, 77.896744
• If I walked around my yard collecting multiple points, I could
create 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 spatial
vector data

5. The Earth from Above
• Virtual globe tools like Google Earth have
made images of the Earth easily accessible
• Most geographic image data comes from
satellites and airborne sensors, but you can
even make your own DIY Drone now
• Geographic image data is raster data, which
captures information by assigning values to
cells in a grid

6. The Earth from Above
• The size of raster grid cells determines how
much resolution you have for the image

7. The Earth from Above
• The science and technology associated with
imaging the Earth is called Remote Sensing
• It’s not just photographs – it can involve the
use of lasers (LIDAR) and infrared sensors

8. The Earth from Above
Source: Science@NASA: http://science.nasa.gov/science-news/science-at-nasa/2011/16may_groundtracks/

9. Source: USGS: http://coastal.er.usgs.gov/hurricanes/sandy/lidar/

10. Source: USGS: http://coastal.er.usgs.gov/hurricanes/sandy/lidar/

11. Maps and the Geospatial Revolution www.coursera.org/course/maps
Twitter @MapRevolution
Online Geospatial Education @ Penn State www.pennstategis.com
This content is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License