Download - IBIS GIS Mapping Missouri “Show and Tell”. Outline 1.What is KML 2.Why we chose KML 3.Show and Tell
IBIS GIS MappingMissouri “Show and Tell”
Outline
1. What is KML2. Why we chose KML3. 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.
How Does the Plug-in Solution Work(Links: web service )
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