Transcript Slide 1

By Jim Graham
May, 2008
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How GoogleEarth Works
Display Excel Data in GoogleEarth
Creating KML Files for GoogleEarth
Web Server
Local Computer
Internet
Satellite Images
Spreadsheet Files
GoogleEarth
KML Files
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Created by Denver-based company, Keyhole
An application that runs on your computer
GIS Services for various layers
A system that you can add data to
Commercially owned
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Common file formats:
◦ Word (*.doc)
◦ PowerPoint (*.ppt)
◦ Excel (*.xls)
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Shapefiles
Coverages
GeoTIFF
Lots of others
Is KML a GIS format?
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Small Graphics Markup Language (SGML)
HyperText Markup Language (HTML)
Extensible Markup Language (XML)
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Based on XML
Very simple, flexible format
Can be create very complex files
Not an industry standard (could change at
any time, only works in GoogleEarth)
KML Documentation:
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Or search on ‘KML’ into Google
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http://code.google.com/apis/kml/docu
mentation/
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Rasters (photos)
◦ Satellite
◦ Aerial
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Vector Data
◦ Points
◦ Polylines/Paths
◦ Polygons
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Add Placemark
Add Path to and from somewhere
Add Polygon around your school
Save As… KML files
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KML is still very new
Shapefiles are the most common GIS vector
format
Converters are coming
Shapefiles are much more limited than KML
files (i.e. it’s easy to go from Shapefile to
KML, can be harder to go from KML to
Shapefile)
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When should data be in a local file vs. on a
web server?
What are the possible futures for KML?
Web Server
Local Computer
Internet
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Problem: Display spreadsheet data in
GoogleEarth
Solution:
◦ Use an Excel “Add-In” that converts data in
spreadsheets to a KML file
◦ Open the KML file in GoogleEarth
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Actually Excel files that include “Macros”
Hidden in your “Add-In” folder
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Install WriteToKML Add-In to your system
Make WriteToKML available to Excel
Add a custom tool to Excel
Use the tool to save a KML file
Make more interesting descriptions
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Discussion point: What type of data would
you collect to make this work?
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The WriteToKML Add-In is limited
Does not support:
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polygons and paths
Graphics
Icons
Lots of other features of KML
http://earth.google.com/kml/index.html
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Simple text files without any formatting
Write in NotePad (TextEdit on the Mac), not
MS-Word or other “word-processor”
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Search on “KML” in Google
Click on “KML Documentation Introduction”
Click on “KML Tutorial”
Scroll down to light blue boxes
Copy everything in the box into a new
NotePad file
Save as “text.kml”
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What is the approximate coordinate?
What is the name?
What is the description?
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Open GoogleEarth and Notepad
Steps:
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Edit in NotePad
Save to a file on the desktop
Double click on the file
Click “Yes” to reload and view the file
Repeat
Change name, description
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.2">
<Document>
<Placemark>
<name>Name of the Placemark</name>
<description> Description appears in the balloon
</description>
<Point>
<coordinates>102.595626,14.996729</coordinates>
</Point>
</Placemark>
</Document>
</kml>
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Multiple points
◦ Add “Document” tags”
◦ Add another point, save, view
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Some fun stuff
- Photos, paths, etc.
KML “Developer’s Guide”
KML Reference
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How would you use this in your classroom?
What types of data would kids find cool to
put into GoogleEarth?
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Web server/client architecture
Spatial Data File format: KML
Converting from Excel to KML
How to edit KML files