294 Part IV — Google Earth Hacks
Obtaining the Application.
Google Earth can be downloaded from the Google Earth homepage (http://earth
.google.com). There are three versions of the Google Earth application: Google Earthis free for personal use and incorporates satellite images that cover the
entire surface of the earth. The free client also provides access to all of the different
Google Local–supported databases, including those that provide information about loca-
tions, local businesses, and route finding. Google Earth also incorporates the technology
for generating and representing information based on the Keyhole Markup Language
(KML). This is the version that is described throughout the rest of this chapter.
Google Earth Plus is an optional (and low-cost) upgrade to the free client that extends
the functionality of Google Earth to include interfaces to GPS devices, higher resolution
for printed images (higher than onscreen), extended annotation and drawing tools, and a
data importer that will read files in CSV format. Google Earth Plus is supported only on
Windows (at the time of writing).
Google Earth Pro is a professional product and is therefore significantly more expensive
than the Google Earth Plus upgrade. It incorporates much faster download times and
data streaming, extended layers and overlay support, and improvements to the annota-
tion system that enable you to develop much more detailed overlays directly within the
Google Earth application. Google Earth Pro is supported only on Windows (at the time
of writing). Google Earth Pro also supports a number of extension modules, including
those for making movies (by “flying” through the Google Earth data), a high-resolution
printing module, and data modules providing traffic and shopping data.For all three applications, Google Earth is merely the desktop interface to the data on the
Google Earth servers. You must first download the client that enables you to view and interact
with the data. Then you can connect to the Internet to obtain and download the images that
are displayed onscreen.There is a fourth Google Earth application, Google Earth Enterprise, which is designed to provide
Google Earth features in combination with heavily customized information within an enterprise
environment. Google Earth Enterprise is technically a range of applications that work together to
provide Google Earth data, combined with your own enterprise information, such as statistical
and customer data. For more information see the Google Earth Enterprise web site at http://
earth.google.com/earth_enterprise.html.Google Earth Features
The Google Earth application provides an interface to the Google satellite imagery, and
because it is not limited by the interface available through a web browser and JavaScript, there
is a lot more flexibility and interactivity in the Google Earth application. Some of the key dif-
ferences are detailed shortly. First, examine Figure 15-1, which shows the basic interface of the
Google Earth application.