Europe and Russia in the Media CenterGeography, Mapping, and Images

Amanda Clarke HenleyGIS LibrarianReference Department, Davis Library

Today’s Presentation

• Online Cartographic Resources

• Virtual Globes

• Google Earth• Tour• Hyperlinks• Image Overlays• Instructions and Resources

• QuestionsImage: http://englishrussia.com/?p=1466

Cartographic Resources• Perry-Castañeda Library Map Collection (UT Arlington)

• Very large collection of digital maps• http://www.lib.utexas.edu/maps/

• David Rumsey Historical Map Collection• http://www.davidrumsey.com• Over 13,600 maps online• Focus: rare 18/19th century N and S America• Historic World maps• Europe, Asia, and Africa

• Map History Gateway • Retired Map Librarian, British Library, London• Annotated links to many, sites with online maps• http://www.maphistory.info/index.html

• National Geographic and ESRI Map Machine:• Interactive atlashttp://plasma.nationalgeographic.com/mapmachine/index.html

• United Nations Cartographic Section• Good source for recent maps, not all countries are listed• http://www.un.org/Depts/Cartographic/english/htmain.htm

Interactive Globes

• NASA World Wind• ArcGIS Explorer• Google Earth

“3D Interface to the Planet”

Satellite imagery and spatial data on a 3-D virtual globe

Easy to use interface

NASA World Wind

Free Open Source Public Domain Data

• Not Open Source• From ESRI, world

leader in GIS• Commercial data• GIS Oriented• Allows for some GIS

capabilities:visibilitymodelingproximity search

ArcGIS Explorer

Google Earth

• Not Open Source• Originally Keyhole Earth

• Developed for US Intelligence

• Commercial Data• Social Object

• Google Earth Community• Panoramio• Wikipedia

Inspiration for Keyhole Earth/Google Earth

• Michael Jones, CTO of Google Earth, presented: “A Sense of Place” at the second Map Middle East Conference, 2006

• Goal to Geographically Organize World Data• Described Google Earth as GIS “for the 5.999999 billion

people of the world’s 6 billion population who don’t know or care what GIS is”.

• Inspiration for Google Earth:• “Father of GIS” Roger Tomlinson, who in the late 1960’s wrote

that the ultimate GIS which would be a computer globe of interactive data…

• Mr Spock’s Tricorder… “could tell the science officer all the information he needed to describe his local environment”.

http://www.edparsons.com/?p=203Scott Madry pers com.

• Data Models Simplify Real World Phenomenon into Abstractions

• Raster (Grids and Images)• Vector (Points, Lines, and Polygons)

Modeling the Earth with Spatial Data

Two Main Spatial Data Models:

Raster Data

• Raster Data divide the earth’s surface into a grid• Each grid cell is assigned a value that represents

some characteristic of the earth at that location (elevation above sea level) or imagery

• “Spatial Resolution” is based on cell size – level of generalization

Satellite Imagery – Landsat TM

Vector Data• Vector data use coordinates to express the

location of objects (x, y) • Features can be represented by:

• a single set of coordinates (point)• two sets of coordinates (line)• Three or more sets of coordinates (polygon or

polyline)

Google Earth Data

• Google Earth Provides both raster and vector data• Imagery at various resolutions cover the Globe• Vector data includes

• Points of interest, Boundaries, etc.

• Additional geospatial data can be overlayed- XML-based format

• KML (Keyhole Markup Language)• KMZ Zipped KML File

• Points, Lines, Polygons and Images can all be represented in KML/KMZ

• Use the interface to create placemarks, save as KML or KMZ

Google Earth Data

Imagery

• Satellite Imagery and Aerial Photos compiled from many different sources, mosaiced to cover the entire globe

• 15m spatial resolution at coarsest, much higher for many areas

• U.S. high resolution for many locations (1m, 0.7m, 0.3m). 0.15m aerials for Cambridge, MA and Google Campus, Las Vegas has 5in

• Global: some 1m, some 0.7m in urban areas, UK has 15cm (6in)

• Most less than 3 years old

• Imagery being updated all the time

Source: Google Earth website, Google Earth Blog (Frank Taylor) and pers comm, Scott Madry

Google Inc. Mountainview, CA

Newer Is Better!?

2002 Imagery 2007/2008(?) Imagery

3-Dimensional Mosaic of Imagery

~10m resolution

Sub-meter resolution (~100cm)

Resolution Affects Sharpness of Imagery

Metadata Would Be Nice

• Instead, we get:• Google Earth Image Coverage:• http://earth.google.com/data.html• List of Cities with available high-resolution data:• http://earth.google.com/coverage/coverage_list.pdf• Image Dates, Images are from “sometime in the last

three years” …“And because the imagery comes from a variety of sources, and is mosaic-ed together, it is difficult for us to specify the date of a city or region (a single city may have imagery taken from different months).”

• Source: http://earth.google.com/images_dates.html

Google Earth DataElevation Data• Based on Shuttle Radar Topography Mission (SRTM), 30m,

sometimes 90m• No Bathymetry data (seabed is a graphic)

Source: Wikipedia Google Earth entry, and pers comm, Scott Madry

Swiss Alps Tyrrhenian Sea

Google Earth in the Classroom (or Media Center!)

• Google Earth Lessons:

• Google UK Lessons (11-14) • The British Empire• Elizabeth and the Spanish

Armada• Comparing Castles• The Slave Trade

• Google Earth 101 for Educators

Thank You.