Experiments with Google Earth and Google Maps
Experiments with Google Earth and Google Maps
Experiments with Google Earth and Google Maps
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<strong>Experiments</strong> <strong>with</strong> <strong>Google</strong><br />
<strong>Earth</strong> <strong>and</strong> <strong>Google</strong> <strong>Maps</strong><br />
Kirk Keller <strong>and</strong> Mark Brunner
Where It All Began<br />
► Desire to provide up to date brochures on dem<strong>and</strong><br />
to the public via the Web complete <strong>with</strong> maps<br />
• Want to pull Area information from database<br />
• H<strong>and</strong> drawn maps could not be updated <strong>and</strong> uploaded<br />
in a timely manner<br />
► Looking for something flashy <strong>and</strong> quick to market<br />
• <strong>Google</strong> <strong>Maps</strong> was changing the way the public was<br />
using <strong>and</strong> expecting online maps<br />
• <strong>Google</strong> <strong>Earth</strong> was a hot new thing
<strong>Google</strong> <strong>Earth</strong><br />
► KML File – Keyhole Markup Language<br />
• XML grammar <strong>and</strong> file format for modeling <strong>and</strong> storing<br />
geographic features for <strong>Google</strong> <strong>Earth</strong><br />
• Open <strong>and</strong> Close HTML Type Tags<br />
<br />
<br />
long,lat,alt<br />
long,lat,alt<br />
long,lat,alt<br />
long,lat,alt<br />
long,lat,alt<br />
long,lat,alt<br />
long,lat,alt<br />
long,lat,alt<br />
<br />
Build KML Process – Step 1<br />
► Ingest Shapefile<br />
• Decode File Structure <strong>and</strong> Parse Data<br />
►“ESRI<br />
Shapefile Technical Description”<br />
• An ESRI White Paper – July 1998<br />
►Convert Points from UTM to Latitude/Longitude<br />
• Save Polygon Points as Component Pieces<br />
►Placemarks<br />
• DBF Data<br />
• Calculated Midpoint Lat/Long<br />
►Parts<br />
• Individual Ring Direction (Inner Ring vs Outer Ring)<br />
►Points<br />
• Longitude/Latitude/Altitude<br />
• Point Order
Build KML Process – Step 2<br />
►Create Create KML File<br />
• Write basic header information for all objects<br />
►Placemark<br />
attributes – Icon graphics/characteristics<br />
►Polygon attributes – Line color/weight, Zoom level<br />
• Loop through each shape to write Placemarks<br />
►Description information from various databases<br />
• Shapefile DBF, L<strong>and</strong>s, Atlas, Regulations<br />
►Point Point at area midpoint <strong>with</strong> icon<br />
►Polygon points organized in sequence<br />
• Outer rings for main shapes<br />
• Inner rings for exclusions
Distributing KML to Public<br />
► Issues <strong>with</strong> basic KML file<br />
• Resulting KML is 6MB<br />
►Too large for casual download<br />
►Zipped file (KMZ(<br />
KMZ) ) is 1MB<br />
• If public saves Temporary Places then they will not be<br />
updated as KML is changed<br />
► Use NetworkLink in separate KML<br />
• Reference to real KML is all that is saved in Temporary<br />
Places<br />
• Real KML will be loaded fresh each time <strong>Google</strong> <strong>Earth</strong><br />
loads the NetworkLink reference
NetworkLink Example<br />
<br />
<br />
<br />
MDC Areas<br />
<br />
<br />
http://mdc4.mdc.mo.gov/<strong>Google</strong>/MDCareas.kmzhttp://mdc4.mdc.mo.gov/<strong>Google</strong>/MDCareas.kmz<br />
onceonce<br />
<br />
<br />
<br />
Demo Goggle <strong>Earth</strong><br />
Area KML File
<strong>Google</strong> <strong>Maps</strong><br />
►KMLKML file is too large for <strong>Google</strong> <strong>Maps</strong> to<br />
h<strong>and</strong>le in one shot<br />
• Multiple separate KML files would be unwieldy<br />
to maintain<br />
►Why Why not dynamically create shapes as they<br />
are requested<br />
• Need shape information in database<br />
►Use the Placemark, , Part, <strong>and</strong> Point tables created in<br />
the shapefile ingestion process
Demo Goggle <strong>Maps</strong><br />
Area Lookup
<strong>Google</strong> <strong>Maps</strong><br />
►<strong>Google</strong> <strong>Google</strong> maps allows for 'social mapping' or<br />
'crowd sourcing'<br />
►Federal, Federal, state <strong>and</strong> local agencies can make<br />
xml markup (GeoRSS(<br />
GeoRSS) ) available to each<br />
other <strong>and</strong> the public<br />
►Each Each of these agencies (or the public) can<br />
aggregate this data <strong>and</strong> quickly build a map
<strong>Google</strong> map syndication<br />
►Missouri Missouri River Water Trails<br />
►Phase Phase I: manually pull <strong>and</strong> validate data<br />
from various city, commerical, , state <strong>and</strong><br />
federal agencies<br />
►Phase Phase II: pull this data from xml feeds on<br />
participants Web sites
How it works<br />
►City City builds xml file on their site listing points<br />
of interest<br />
►City City pulls that xml into a <strong>Google</strong> map for<br />
their own site<br />
►Aggregation sites (like Mo River Water Trail)<br />
looks at the city xml file <strong>and</strong> pulls relevantly<br />
tagged items<br />
►Result: Result: City information is kept up to date<br />
on aggregation sites
Demo Goggle <strong>Maps</strong><br />
GeoRSS Feeds
Experimentation Opportunities<br />
►Hackers Hackers Ball<br />
• Examples of <strong>Google</strong> <strong>Earth</strong> <strong>and</strong> <strong>Google</strong> <strong>Maps</strong><br />
implementations to play <strong>with</strong><br />
►Wednesday Workshop<br />
• Tool available to create your own KML file from<br />
shapefile <strong>and</strong> DBF<br />
• Creation of GeoRSS files to feed <strong>Google</strong> <strong>Maps</strong><br />
along <strong>with</strong> explanation of how to build a<br />
syndication framework
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