One-Stop Shopping for Maps1 May, 2007 By: Andrew G. Roe,P.E.
A governmental consortium aims to provide access to integrated GIS information for all.
Anyone who has surfed the Internet for geospatial data knows what a circuitous route it can take. You might find planimetric data on one Web site, topographic data on another, demographic data on another and so on. The challenge is often compounded when you try to combine data from multiple sources into a single map.
A governmental consortium seeking to simplify this process is stepping up efforts to expand the data available at a single Web site. The GOS (Geospatial One-Stop) project, launched nearly five years ago and managed by the United States Department of Interior, is now actively recruiting local governmental agencies to port their maps and other data to the GOS Web site, thus enabling users to access a wide variety of data at once, rather than jumping to multiple Web sites.
The one-stop concept allows users to combine layers of data from multiple sources and build custom maps on the fly. While attractive to public and private agencies alike, the federally led project is only as valuable as the data it exposes, and much of that data resides on local government Web sites. The GOS is reaching out to local sources because "up to two-thirds of [geospatial] data is at the local level," said Robert Dollison, GOS project manager for the United States Geological Survey, one of 19 federal agency partners in GOS.
USGS data can be merged with transportation atlas data to highlight major highways in a topographic map.
To help encourage more local participation, the USGS (United States Geological Survey) enlisted Sam Wear, assistant CIO for Westchester County, New York, to act as a part-time liaison with local governments for one year. In this role, Wear is trying to convince local governments that participating is beneficial and easy. "We want to make it easy for local governments to register their data," he said. Registration can be done in as little as 15 minutes, according to Wear.
The recent push to expand the GOS is tied closely to the improved capabilities of Web services -- software that supports real-time interaction over the Internet. "Web service technology has improved considerably over the last two years," said Wear. Improved Web programming capabilities, along with faster computers and broadband capabilities, means users can build custom maps in real time, rather than downloading files and combining data offline. “You don’t have to access data layers individually. You can 'fuse' data and build custom maps," said Wear.
The GOS portal allows users to access various categories of data, such as agricultural, environmental, topographic and transportation. Users can search for maps and other information by locale and type and then add other data to build composite maps. For example, USGS topographic data can be overlaid with flood mapping, additional local mapping and census data and displayed in one view. Coordinate conversions are generally handled on the GOS portal with no action required by the user.
Multiple local and federal maps can be viewed simultaneously.
Data sources and formats vary widely on the GOS, ranging from interactive map services to static images with no interactive capabilities. Users can access "live" data and maps, such as ArcIMS or WMS (Web Map Server) map services, using software tools such as ArcGIS or ArcExplorer. Some datasets are downloadable and can be saved on a user's local machine, while others must be ordered online and delivered in CD or DVD format.
Registered users can save maps for future use, publish data and search for partners for data collections and acquisitions. Wear hopes the partnering concept will entice local government contributors to grow from approximately two dozen to several hundred over the next year. In addition to its federal agency partners, the GOS solicits input from a board of directors that includes non-federal groups such as the National League of Cities and the National Association of Counties. "We’re trying to expose public-facing Web services and provide access to rich data," said Wear.
Based on the few hours I spent browsing the GOS Web site, the one-stop concept appears to offer some intriguing possibilities, although the system still has some bugs to work out. I received several error messages and notices that remote servers were not responding. Users should also verify accuracy when merging data from disparate sources. But the potential to build custom maps on the fly and access the wide-ranging geospatial data under one roof should appeal to many users. If the GOS can continue to build interest among data owners and smoothly integrate data, the GOS site could become a favorite in the GIS community.
About the Author: Andrew G. Roe
In her easy-to-follow, friendly style, long-time Cadalyst contributing editor and Autodesk Technical Evangelist Lynn Allen guides you through a new feature or time-saving trick in every episode of her popular AutoCAD video tips. Subscribe to the free Cadalyst Video Picks newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!