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MAGIC 2.0: The Development of Web-Based GIS Applications for Historical GIS Data
For more Connecticut maps visit magic.lib.uconn.eduor our online mapping site www.econmap.com
For more info about Cadcorp’s GeognoSIS visit:www.cadcorp.com or www.progeos.com
For more information please email [email protected] and poster compiled by Benjamin SpauldingDepartment of GeographyUniversity of Connecticut860-486-4589
IntroductionThe Map and Geographic Information Center (MAGIC) at the University of Connecticut has been a leading source for Connecticut and New England geospatial data for over the past 15 years. With use increasing every year and users becoming more sophisticated MAGIC has embarked on an ambitious project to serve its historical geospatial data through web mapping, web file services and a new online mapping viewer. These new tools will allow users to access thousands data files including historical aerial photographs, scanned and georeferenced historical maps and a growing collection of historical vector data. This poster will outline the development and need for the system, its development and implementation and user response. Items that also will be discussed will include the variety of data formats that are served through MAGIC's distribution system, system performance, and future directions.
Problem
How can we improve access and usability of current and future online georeferenced data sets?
Visitors to MAGIC’s former website were confronted with several issues. Users were limited to viewing a single map at a time within their browser and could not create maps of the data. There were several technical issues as well. Users were often met with internet browser and plugin configuration errors. For example, the prior system would not work with Firefox and had issues with ArcGIS.
Also, MAGIC’s former system was not friendly to those interested in geospatial data but did not have GIS experience. Much of the data was intended for use by GIS experts, not the general public. One of the goals of the new system was to enable users who did not have GIS access to make informed decisions with MAGIC’s data.
Solution
The goal of the new program was to increase access and provide an online mapping tool that could be utilized independent of experience, operating system or internet software.
MAGIC also wanted a system that allowed for its data to be preserved in its native format. Many of the georefrenced map mosaics were generated as ER Mapper ECW files . These compressed images are a valuable resource and converting these datasets into other formats would have been a time consuming process.
Details about the System
The new online mapping tools at MAGIC run off of the GeognoSIS GIS server, an OpenGIS software developed by Cadcorp, a British GIS software firm. GeognoSIS acts as a map server pushing out data to users over the internet in the form of PNG or JPG files.Maps served in this software come from a variety of data types including ECW files, coverages, shapefiles, tiff files and many other formats saving MAGIC time in implementation and maintenance.
Google Mash-Ups
Using the Keyhole Tool one can make direct comparisons between maps and data layers
Historical aerial photography is one of the most requested collections at MAGIC. The new online mapping tools allow a level of access never before realized at MAGIC. In the above example the keyhole tools compares aerial photography of the Mohegan Sun Resort between 1934 and 2004.
Web Map Services
Online Mapping
MAGIC’s Web Map Service
A Web Map Service (WMS) takes georeferenced maps from a server and renders them over the internet in an image format into a GIS program. The WMS reads into a number of GIS software systems including ArcGIS.
Patrons can use this information to digitize new data or use it as a backdrop for a map. MAGIC hopes that this service will eventually replace the ECW plugin that has been running for several years. The WMS does not require users to download any type of plugin as it is a built in tool in most GIS programs. In fact, the WMS service will expand the number of software platforms that can read in MAGIC’s large georeferenced datasets.
Features of the WMS
•Publishes large GIS data sets over the internet through a GIS server.
•When users connect to the database they will receive a PNG or JPG file in their GIS program.
•Data cannot be edited – acts as a background image.
•Depending on the user’s internet connection download speeds are excellent.
•Users do not have to worry about storing large imagery GIS datasets.
•The WMS provides an efficient way to share large datasets.
MAGIC’s Online Mapping Site
MAGIC’s user group includes students and faculty at the University of Connecticut and other Connecticut State Universities. Another large base of users includes state and municipal employees and private companies. MAGIC’s wide user base uses the new web site for a number of purposes including site research using the historical aerial photography. Patrons also use the data to making comparisons in land use over time between.
Using the GeognoSIS server to power the new website patrons can browse a growing number of georeferenced historical maps of Connecticut. Users can toggle between different map layers including historical maps, aerial photography and Connecticut vector data. They also have the ability to search and zoom to specific locations, making the online maps more accessible and easier to use.
One of the most popular features of the site is for users to create their own custom maps. This feature allows for users to print a PDF file from the online mapping tools to their own computer. Some of the most popular layers printed include the 1934 aerial photography, USGS topographic maps and the 2004 aerial photography of Connecticut.
This service can be expanded quickly and easily. MAGIC has added online maps of the University of Connecticut campus, the presidential election results for Connecticut and a number of new historical maps.
Some of Connecticut’s most detailed historical maps are available in the online viewer
Using the Keyhole tool users can view directly through the map to one behind it, enabling a direct comparison of maps.
WMS in ArcGIS
Access to MAGIC’s data has greatly improved with the implementation of the WMS. The use of the WMS has also improved in ArcGIS 9.3. Users can now add a single layer into their GIS project from the WMS improving download times.
WMS in Google Earth
MAGIC’s WMS can also be read into Google Earth. This increases access to the data as Google Earth is a easy to use, free software.
To aid patrons MAGIC has created a series of WMS help tools @ http://magic.lib.uconn.edu/help/help_WMS.htm
MAGIC’s Google Map Project
One of the fastest growing segments of the online mapping community is the development of Google Mash-Ups. Using the Google Map API and code developed by MAGIC, Cadcorp and various Google Map developers a series of online maps using the MAGIC WMS has been created.
The goal of this project is provide another avenue for users to access this information. The Google Map API is simple to use and to develop. Over the next several weeks MAGIC will be developing tutorials and code so that others can create their own Google Mash-Up pages using their own data in combination with MAGIC’s WMS data. The flexibility of the Cadcorp GeognoSIS WMS and the Google Maps API will allow users to customize their own Mash-Up sites with MAGIC’s historical maps and their own markers, text and KML files .
Future and Ongoing Projects
•Over the next several months MAGIC will be adding a number of datasets to its website including:
•Connecticut’s USGS and CGNHS geology maps by quadrangle to the online mapping site and to the WMS.
•Historical road maps of Connecticut towns developed by the Connecticut DOT during the 1950s, 1960s, and 1970s.
•Georeferenced historical hydrological maps of Connecticut Watersheds.
•Georeferenced railroad evaluation maps for the New York-New Haven Rail line from the late 1800s
The data layers that are read into the Google Maps Mash-Up come from the GeognoSIS WMS. The data are tiled by the javascript developed by Cadcorp and are easily read into the webpage.
MAGIC has already been contacted by various groups who want to create their own Google Mash-Up pages to display a variety of information including town histories, development changes and historical aerial photography.
With hundreds of unique maps in the WMS users will be able to create a variety of individual Mash-Up pages for a variety of topics.
A number of historical maps are already available for use from MAGIC’s WMS.
The Google API allows for the use of the Google address search tool. This enables users to quickly find their location of interest with a high degree of accuracy.
Creating web pages with the Google API and MAGIC’s historical maps will enable users to develop their own unique historical map mash-ups.
Benjamin SpauldingDepartment of GeographyUniversity of Connecticut
