Reveal attribute data with just a click in updated Gmap4

By Joseph Elfelt

In August 2013, we introduced our readers to Gmap4, an enhanced Google map viewer and GIS client that is free for non-commercial use. According to its creator, Joseph Elfelt, it was the first general purpose REST and WMS viewer built on the Google Maps API. Why was that important? Because it gave everyone with access to the internet the ability to display user-specified GIS data on a map, then view it through the familiar and user-friendly Google Map interface, helping open the world of GIS to the general public. The latest release of Gmap4 goes one step further, providing users with GIS attribute data with just a click.

Government agencies at all levels are hosting an amazing variety of data on GIS servers. One kind of GIS data puts symbols on a map; another kind of GIS data consists of information about each symbol, its attributes. Now anyone willing to read and follow a few simple instructions provided on the Gmap4 website can specify the parameters for the GIS data they wish to view.  The map will display the GIS symbol data and then each time the viewer clicks on a GIS symbol, the most up-to-date GIS attribute data available is displayed.

Gmap4 is a valuable tool for anyone who is interested in outdoor activities where an in-depth understanding of the area is helpful. Its wide range of features includes:

  • Touch-friendly interface on mobile devices
  • Geolocation with a symbol that follows you as you move
  • High resolution U.S. Geological Survey topographic map
  • Coordinate grid for U.S. National Grid and Universal Transverse Mercator
  • Search functions

“I wanted to do more in order to make GIS data more widely available,” Elfelt said. “My goal is to help educate everyone about the nearly endless amount of GIS data that is freely available and how easy it is to display that data on the ever-so-familiar Google maps.”

To view the Quick Start information and start using Gmap4 today, visit the Gmap4 homepage.

Published Wednesday, March 25th, 2015

Written by Joseph Elfelt

Published in



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