GIS

Tech Trends: Around the World in 80 Seconds

1 Sep, 2005 By: Kenneth Wong

Google introduces 3D geography for everyone


One evening last week, overcaffeinated and bored, I decided to retrace the ambitious route undertaken by Phileas Fogg in Jules Verne's Around the World in Eighty Days. Because I cannot disappear for 80 days without alarming my editors, Fogg's methods—steamships, locomotives, air balloons and Indian elephants—were out of the question. So I opted for a virtual journey in Google Earth, a terrain-exploration application currently in beta and available for download at http://earth.google.com. Fogg's fictional journey began at the Reform Club in London, proceeding through Suez, Bombay, Calcutta, Hong Kong, Shanghai, Yokohama, San Francisco, Omaha, Chicago, New York, Liverpool, then back to London. It took me about three minutes to identify each place and put place markers on them. Then I was off—navigating his route in a browser-like window. Verne might have been astonished to learn that Fogg's 80-day adventure took me less than 80 seconds.

A Peek Inside Google Earth's Keyhole

Google Earth is the outcome of Google's acquisition of Keyhole in October 2004. A private company founded in 2001, Keyhole offers a software product that lets users retrieve and explore geospatial information and satellite images from an intuitive interface. John Hanke, general manager of the Keyhole Group at Google, explains how the technology works: "Basically it drapes satellite imagery onto a wire-frame model of the world. So the three-dimensionality varies from one locale to another, depending on the level of details available in geometry and aerial photography. The geometry is originally created by NASA, by measuring every 90 meters of the surface to show hills, mountains and valleys."

The measurement, Hanke points out, isn't dense enough to accurately detect the highly clustered metropolitan areas. For those, separate geometric models have to be created. This explains why the Grand Canyon (figure 1) appears with all its precipices and crevices fully formed, but downtown Mumbai (Bombay) gets blurry when zoomed in.

 Figure 1. Google Earth simulates 3D terrains by draping 2D imagery over a wire-frame of the world's geography. This method produces better results in certain areas, such as the Grand Canyon, with well-defined contours.
Figure 1. Google Earth simulates 3D terrains by draping 2D imagery over a wire-frame of the world's geography. This method produces better results in certain areas, such as the Grand Canyon, with well-defined contours.

Google Earth's data is quite good for North America, Western Europe, parts of Eastern Europe and parts of the Australian coast, but still limited for the rest of the world. For 38 major U.S. cities (my hometown San Francisco among them), the data is so good that you can zoom in from space level to street level and examine the neighborhoods at close quarter, moving from one rooftop to another. As with MapQuest and other browser-based mapping applications, you can use Google Earth to query and display practical information, such as locations of parks, ATMs, coffee houses, hotels and subway stations (for more, see the Feb. 2005 "Spatial Technologies" column; http://gis.cadalyst.com/0205spatial ). Unlike traditional mapping applications, which display data in 2D, Google Earth shows a 3D map that users can tilt, zoom, pan and fly though. Furthermore, Google Earth generates the desired map by dynamically stitching together geometry and images from a variety of sources, so the navigation is both seamless and speedy.

Basic Google Earth is free. Google Earth Plus, a more advanced version for home and personal use, and Google Earth Pro, a commercial version, are sold by subscriptions for $20 and $400 per year, respectively. Google Earth Enterprise is an ASP (application service provider) solution for integrating geospatial data with enterprise data.

The Land Grab

Not to be outdone by Google, Microsoft's Bill Gates put in an appearance at the D3 conference in Carlsbad, California, in May to preview MSN Virtual Earth. Using technology and data from MapPoint (www.mappoint.com) and Terra Server (www.terraserver-usa.com), MSN Virtual Earth serves up aerial images not only straight down but also from a 45° angle. The oblique perspective, which MSN refers to as bird's eye, comes from Pictometry (www.pictometry.com) under an exclusive license with Microsoft. Amazon.com, which recently leapt into the search engine business with its A9.com, responded by dispatching an army of trucks equipped with digital cameras and GPS receivers to take photos of U.S. businesses. The data is intended for an online service called BlockView, which displays photos of storefronts alongside business information, served via a map interface. At press time, MSN Virtual Earth (www.virtualearth.com) is not yet available. A9 BlockView is live (http://maps.a9.com), with nationwide data acquisition still in progress.

MSN and Amazon have good reasons to spring into action. Google Earth has been received with enthusiasm and optimism by users and industry analysts alike. Marketed as a tool for nonspecialists, Google Earth is not likely to become a direct competitor to existing civil and GIS solutions that target the professional market. But the introduction of affordable geospatial data for mass consumption—by none other than one of the biggest search engine providers—will have widespread impact. And Keyhole's KML (Keyhole markup language) document is publicly available (www.keyhole.com/kml/kml_doc.html enabling developers to write clients for creating and sharing data with Google Earth.

The Professionals

Jack Dangermond, president of ESRI (www.esri.com), welcomes Google Earth and Microsoft's Virtual Earth as "complementary systems for geospatially enabling the Web." He sees Google Earth as a consumer application that promises to introduce people to geospatial imaging and 3D geography. "Over time, we see it contributing to our business by making people aware and better appreciate what our [professional] users do. More and more, they are serving their data on the Web. Our focus is to build technology that supports not only geospatial data management, but also advanced analysis, cartography and GIS publishing using Web services." OnStar, which delivers location-based services to luxury vehicle owners, is among ESRI's clients.

Soon after Google Earth launched, Spatially Adjusted, a blog maintained by an ESRI developer, registered an entry soliciting efficient ways to import ESRI ArcGIS shapefile points into Google Earth (www.spatiallyadjusted.com/gis). The poster had figured out how to do it, but was hoping for easier methods. Dangermond says we can expect announcements about Google Earth integration from ESRI soon.

Gary Lang, vice-president of engineering for Autodesk Infrastructure Solutions Division, predicts the professional GIS market is likely to benefit from the enormous interest generated by Google Earth. "GIS has always been a specialized genre, not freely available in the mass market," he points out. "But suddenly we see O'Reilly [a technical book publisher], which has never published GIS books before, releasing books on GIS." Between Amazon.com and O'Reilly's home page (www.oreilly.com), I found two books: Web Mapping Illustrated: Using Open Source GIS Toolkits by Tyler Mitchell and Mapping Hacks by Rich Gibson. Both were released—as if on cue—in June 2005, the same month Google Earth was launched. Lang points out that for Autodesk customers, Google Earth can be another data source. Autodesk's civil and infrastructure solutions support the WMS protocols, which let users wrap their own raster maps on top of Google Earth data (figure 2).

Figure 2. Some professional GIS products, like those from Autodesk with support for WMS (Web map server) protocols, let users wrap their own raster maps on top of Google Earth data.
Figure 2. Some professional GIS products, like those from Autodesk with support for WMS (Web map server) protocols, let users wrap their own raster maps on top of Google Earth data.

ARCHIBUS (www.archibus.com), an infrastructure and facilities management developer, recently added support for Google Earth to its products. The company anticipates that clients using Google Earth in conjunction with ARCHIBUS/FM will be able to analyze real estate portfolios, conduct underground cableway maintenance or examine building adjacencies that may not be easily detectable on maps alone.

A Brave New World

"The old data set," explains Keyhole Group's Hanke, "is about 1 kilometer per pixel. The new data set just launched two months ago is 15 meters per pixel, with urban areas going as high as one- to quarter-meter per pixel. But people still say that's not detailed enough. It goes to show the insatiable appetite for highly detailed geospatial data."

Though most professionals don't consider Google Earth a GIS application, it is already having an effect by increasing GIS literacy among the general population. Many professional GIS solutions providers will be tinkering with their own products to take advantage of Google Earth's growing user base. We can expect announcements from more GIS providers about Google Earth integration and compatibility. They will be kept busy also by the upcoming launch of MSN Virtual Earth. The race is on.

Kenneth Wong is a former editor of Cadence magazine. He explores innovative use of technology as a freelance writer. E-mail him at kennethwongsf@earthlink.net.


About the Author: Kenneth Wong


AutoCAD Tips!

Lynn Allen

Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!
Follow Lynn on Twitter Follow Lynn on Twitter


Poll
Which file format do you use most often for CAD drawing/model exchange?
Native format
PDF
3D PDF
DWF
STEP or IGES
JT
IFC
Other
Submit Vote