Point of Beginning

Surveying GIS: Using ArcGIS Explorer.

January 27, 2009
In several prior episodes of this column, we have talked extensively about the importance of data. We have also discussed the role surveyors play in the overall GIS landscape.



Web-based mapping products such as Mapquest, Google Maps and Microsoft Virtual Earth have exploded onto the Internet and into our lives. Framework products are also available that can work with these online products to allow the user to customize, enhance and leverage those services.

One of the most versatile of the online mapping software packages is ArcGIS Explorer (AGX) from ESRI. And one of the best things about AGX is that it is free--you can download it from the ESRI Web site. There are also several online demos available at this site that show many of the ways AGX can be used to create maps and presentations.

Regular users of AGX will discover that it is a work in progress and is likely to be that way for some time to come. But that is a good thing.

The Open Content menu displaying data sources.

Web 2.0

The big difference between the new AGX and its earlier versions is that the current product--Build 5X--is built for the Web 2.0 concept. Web 2.0 is the term used to describe the constantly changing trends in World Wide Web technology and Web design. Unlike earlier versions of ArcExplorer, which were built on MapObjects and Java platforms, AGX is constructed from the same technology as ArcGIS. And because the technology itself is so dynamic, AGX is constantly evolving to stay current. For example, Web or server GIS is the current technology trend in the GIS community, and AGX allows the end-user to participate in the trend.

In Version 2 and other earlier versions of Arc Explorer, users could view GIS and CAD data on a local drive. They could also connect to some online services. But there were some networking and other limitations with the MapObjects and Java platforms. The new AGX is based on the Open GIS Consortium (OGC) model. It was introduced in 2006, and there have been a half-dozen releases since.

With AGX, the user can author maps using geovisualization−techniques and tools designed to interactively “visualize” spatial phenomena. Maps are created using .xml files. AGX provides a simple way to perform a lot of basic map-related tasks. The buttons and tools from the earlier versions are replaced with easy pull-down menus. The scroll mouse feature and right-clicking does just about everything else. But mostly, AGX is a way to present GIS assets to users in a map format without requiring you or them to make a capital investment.

AGX has most of the functionality you find on the other Web mapping services such as Google Earth and Microsoft Virtual Earth. But with AGX, in addition to locating addresses, getting driving directions and exploring the available online map data, users can add and overlay their own data with no additional plug-ins. And they can use data from the other services. AGX is an ESRI product, but it is influenced by collaborators and business partners that have contributed to its development, including Leica Geosystems, LizardTech and Microsoft.

Parcel data layer from a local database displayed on server imagery.

Adding Your Own Authoritative Data

You can add data to an AGX map in most of the standard GIS formats like geodatabases and shape files. Excel tables, .kml files, .kmz files and even text files can be used. Standard raster formats like GeoTIFF and MrSID can be easily added, as well. CADD files are not supported in this Web version. With AGX, the user just needs to select Open Content from the file menu and navigate to the data. You can also easily create notes and add them to your map view, which makes AGX a great tool for presentations. All you need is access to a database or a fast Internet connection. You can make all types of links. You can even add a video from YouTube to your map.

The Resource Center

When the user first opens AGX, the ESRI default map appears. The default view and menu gives the user a variety of initial choices based on the ESRI default map layers. But there are many more layers available from the online Resource Center, which is easily accessed as the second item on the file menu. Among the useful layers available is the U.S. topo maps layer. The seamless USGS map layer is as powerful as it is useful. Features like the Resource Center make AGX a true server-based GIS product. It can be used to do just about any server GIS task except publish.

Direct GPS dump overlaid on imagery.

Mashups

A mashup is a Web application that takes data from multiple sources and integrates them to be used together as a single published tool. You can’t create a true mashup with AGX because you cannot publish your custom interface configuration to the Web for others to use. However, you can create custom tools for yourself using anyone’s available data and adding your own. Because AGX is built on ArcGIS technology, it has built-in on-the-fly projection. If your data is in state plane coordinates or another known system, it will be added to your map seamlessly.

Other Features

One of the things I like about AGX is the new Symbol file, which is great for adding points to your map or globe (3D map). For example, the user can choose an appropriate symbol for a GPS data collection file exported as either a shapefile or Excel file and overlay the points on any available imagery file. The Transparency Tool even lets the user compare different imagery sets.

Find Fone is another interesting feature that allows the user to link to online phone directories and have the location of the phone appear on the map.

System Requirements

AGX can be downloaded from www.esri.com/software/arcgis/explorer/index.html. It runs on Windows 2000, Windows 2003, Windows XP and Vista. A minimum CPU speed of 1.6 GHz or higher is recommended. Intel Core Duo, Pentium 4 or Xeon Processors are recommended in addition to a minimum of 1GB RAM. For those who are interested in more, you can add additional customization capability by also downloading ArcGIS Explorer SDK (Software Developer Kit).


Glossary

KML:
Keyhole Markup Language is an XML-based language. It was developed for Google but is now more widely used on the web.

Geovisualization: a set of tools and techniques supporting geospatial data analysis through the use of interactive visualization.

Globe: A 3D map.

Markup language: an artificial language that gives structure to how a text value is displayed.

OGC: Open GIS Consortium, OGC is an international voluntary consensus standards organization. UGC: User Generated Content.

XML: Extensible Markup Language is a general-purpose specification for creating markup languages.

Sidebar: The User Forums

ArcGIS Explorer has four of its own discussion forums: Announcements, Installation, General Discussion and SDK Developers. Available at forums.esri.com/Forums.asp?c=184, the user forums are loaded with information about how to get the most out of this free product, and they allow users to submit questions to and interact with other users.