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IBIS GIS Mapping Missouri “Show and Tell”. Outline. What is KML Why we chose KML Show and Tell. What is KML/KMZ. KML is an XML file format that is processed in much the same way HTML files are processed by web browsers.
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Outline • What is KML • Why we chose KML • Show and Tell
What is KML/KMZ • KML is an XML file format that is processed in much the same way HTML files are processed by web browsers. • The difference is that KML files are typically processed by earth browsers such as Google Earth or ArcGIS Explorer. • It is possible to display KML using Google Maps.
Why We Chose KML • Missouri was turned on to KML after watching a webinar presented by Joshua Drukenbrod at EPA on how he was using SAS and Google Earth to display air pollution data. • We decided to implement a solution for our EPHTN portal because it looked to be a minimal solution for being able to view query results on a map. • Benefits of using KML are: • KML is an open standard • A lot of users are familiar with Google Earth or Google Maps • Able to create 3-D maps • It is an easy way to share geographic data with other users.
“Save As” Demo Simple crosstab query. http://localhost/EPHTN_Data_Portal/data_query.html Combine multiple datasets . http://www.epa.gov/air/emissions/where.htm
“Save As” Pros and Cons • Pros • Development is simple • Easy to combine multiple datasets • Easy way to save and share geographic data • Cons • Is not necessarily integrated with the browser • Files can become quite large • User is required to download Google Earth
How Does the “Save As” Solution Work(Links: QUERY_MODULE, Coordinate file , ResultsKML file )
Plug-in Demo http://localhost/EPHTN_Data_Portal/data_query.html
Plug-in Pros and Cons • Pros • Integrates with the browser • File sizes are substantially smaller • Provides an API to build on • Cons • Development is more complex • Number of hits to the web service will be high. Will likely need to look at implementing some sort of caching system. • Requires the user to download the plug-in • Does not have a print option at this time • Will require some development to help users to save and combine datasets.
IBIS CoP Discussion Points • Ability to create choropleth and isopleth maps • Interactive features; • Zoom in and out • Turn layers off and on • Pan • Mouseover for geographic attributes: Limited support in Google Earth browser, however the plug-in support is better. • Printing : Good support in GE browser, but not supported in GE plug-in at this time. • Ability to copy and export to other programs: Good support in GE browser; not sure what is possible with GE plug-in at this time. • What is the basic technology: KML • How is the data presented to the mapping engine: KML (XML) • What are the benefits and limitations of this approach: Able to create isopleth maps; requires user to download additional software. • What are the costs and licensing: http://code.google.com/apis/maps/terms.html • How easy is it to add new geographies: • How do you add new datasets • Can you map more than one variable at a time • Can it be used as a mapping service with IBIS • Can it be part of the IBIS code base • Could it produce maps for IBIS indicators as well as query data