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New! January 8th, 2007 - Check out the latest version of Google Earth (Release 4)

Google Earth | Free

Google Earth combines the power of Google Search with satellite imagery, maps, terrain and 3D buildings to put the world's geographic information at your fingertips.

* Fly to your house. Just type in an address, press Search, and you’ll zoom right in.
* Search for schools, parks, restaurants, and hotels. Get driving directions.
* Tilt and rotate the view to see 3D terrain and buildings.
* Save and share your searches and favorites.

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Formerly known as Earth Viewer, Google Earth was developed by Keyhole, Inc., a company acquired by Google in 2004. The product was renamed Google Earth in 2005 and is currently available for use on personal computers running Microsoft Windows 2000, XP, or Vista; Mac OS X 10.3.9 and above; Linux (released on June 12, 2006); and FreeBSD. In addition to releasing an updated Keyhole based client, Google also added the imagery from the Earth database to their web based mapping software.

The resolution is high enough in many large cities, such as Melbourne, London, Washington, D.C., and Seattle, that it is possible to clearly discern individual buildings, houses, the color of cars, and even the shadows of people and street signs.

The degree of resolution available is based somewhat on the points of interest, but most land (except for some islands) is covered in at least 15 meters of resolution[3]. Las Vegas, Nevada and Cambridge, Massachusetts include examples of the highest resolution, at 15 cm (6 inches). Google Earth allows users to search for addresses (for some countries only), enter coordinates, or simply use the mouse to browse to a location.

Google Earth also has digital elevation model (DEM) data collected by NASA's Shuttle Radar Topography Mission. This means one can view the Grand Canyon or Mount Everest in three dimensions, instead of 2D like other map programs/sites. Since 23 November 2006, the 3D views of many mountains, including Mount Everest, have been improved by the use of supplementary DEM data to fill the gaps in SRTM coverage[4]. In addition, Google has provided a layer allowing one to see 3D buildings for many major cities in the US and Japan.

Many people using the applications are adding their own data and making them available through various sources, such as the BBS or blogs mentioned in the link section below.

Google Earth supports managing three-dimensional geospatial data through Keyhole Markup Language (KML). It is available in a free version, and in licensed versions for commercial use.

[edit] 3D buildings
A 3D model of Alcatraz made on SketchUp and uploaded onto Google Earth
A 3D model of Alcatraz made on SketchUp and uploaded onto Google Earth


Google Earth has the capability to show 3D buildings and structures (such as bridges), which consist of users' submissions using SketchUp, a 3D modeling program. In prior versions of Google Earth (before Version 4), 3D buildings were limited to a few cities, and had poorer rendering with no textures.

Many buildings and structures from around the world now have detailed 3D structures; including (but not limited to): U.S., Canada, Japan, United Kingdom, [1], Alexandria and Pakistan [2]. Three-dimensional renderings are available for certain buildings and structures around the world via Google's 3D Warehouse [3] and other websites.

[edit] Wikipedia and Panoramio mashup

In December 2006 Google Earth added a new layer called "Geographic Web" that includes mashups with Wikipedia and Panoramio. In Wikipedia, entries are scraped for coordinates via the Coor dms series of templates. If the options to show Wikipedia or Panoramio entries are selected, users will be presented with clickable dots in their current Google Earth view. When any of these dots are selected, the user will be shown the Wikipedia or Panoramio entry right in Google Earth. There is also a community-layer from the project Wikipedia-World. More coordinates are used, different types are in the display and different languages are supported than the built-in Wikipedia layer. See: *dynamic resp. static layer.

[edit] Specifications
Google Earth comes with atmosphere effects and seabed
Google Earth comes with atmosphere effects and seabed

* Coordinate System and Projection
o The internal coordinate system of Google Earth is geographic coordinates (latitude/longitude) on the World Geodetic System of 1984 (WGS84) datum.
o Google Earth shows the earth as it looks from an elevated platform such as an airplane or orbiting satellite. The projection used to achieve this effect is called the General Perspective. This is similar to the Orthographic projection, except that the point of perspective is a finite (near earth) distance rather than an infinite (deep space) distance. [4]
* Baseline resolutions
o U.S.: 15 m
o Germany : 1 m or better
o Global: Generally 15 m (some areas, such as South-American countries, are in extremely low resolution).
* Typical high resolutions
o U.S.: 1 m, 0.6 m, 0.3 m, 0.15 m (extremely rare; e.g. Cambridge, MA. and Google Campus, or Glendale, CA.)
o Europe : 0.3 m, 0.15 m (e.g. Berlin, Zuerich, Hamburg)
* Altitude resolution:
o Surface: varies by country
o Seabed: Not applicable (a colorscale approximating seafloor depth is "printed" on the spherical surface).
* Age: Usually less than 3 years old. The date on the picture can be misleading. The minimum is 2 years old due to privacy issues.


Google Earth is unlikely to operate on older hardware configurations. The most recent downloads available document these minimum configurations:

* Pentium 3, 500 MHz
* 128 MB RAM
* 400 MB free disk space
* Network speed: 128 Kbit/sec
* 3D-capable graphics card
* 1024x768, "16-bit High Color" screen
* Windows XP or Windows 2000 (Does not work on Windows ME), Linux, Mac OS X

The most likely mode of failure is insufficient video RAM: the software is designed to warn the user if their graphics card is not able to support Earth (this often occurs due to insufficient Video RAM or buggy graphics card drivers). The next most likely mode of failure is Internet access speed. Except for the very patient, broadband Internet (Cable, DSL, T1, etc.) is required. Again, resolution is not uniform, some towns such as St. Petersburg are only partially available in high-resolution.

In this case, the TerraServer-USA data can identify individual trees but its data is structured in cumbersome tiles. As with much GIS data, the utility of the data is application-dependent for the purpose of determining if resolution is sufficient. Also note that from a usability point of view, TerraServer loses its center point when one zooms in and out where Google Earth browsing is smooth; a clear benefit, but at the price of the somewhat demanding requirements imposed upon the video card.

It is worth noting however, that with some work, images from TerraServer can be integrated as Image Overlays into Google Earth, allowing the user to combine the higher (in some cases) resolution imagery from TerraServer over the smoother Google Earth program.

[edit] Mac OS X version
Google Earth (Mac OS X)
Google Earth (Mac OS X)

A version for Mac OS X was released on January 10, 2006, and is available for download from the Google Earth website. With a few exceptions noted below, the Mac version appears to be stable and complete, with virtually all the same functionality as the original Windows version.

Screenshots and an actual binary of the Mac version had been leaked to the Internet a month previously, on December 8, 2005. The leaked version was significantly incomplete. Among other things, neither the Help menu nor its "Display License" feature worked, indicating that this version was intended for Google's internal use only. Google released no statement regarding the leak.

Currently, the Mac version runs only under Mac OS X versions 10.4 and 10.3.9. Currently, there are no "Plus" or "Pro" versions for the stable release. There is no embedded browser and no direct interface to Gmail. There are a few bugs concerning the menu bar when switching between applications and a few bugs concerning annotation balloons and printing.

The latest version, 4.0.2736, released on February 2, 2007, features, among other things, a new user interface and the option for Mac OS X users to upgrade to the "Plus" version. [5]. Some users reported difficulties with Google Earth crashing in the latest version when zooming in. [6]

[edit] Linux version

Starting with the version 4 beta, Google Earth functions under Linux, as a native port using the Qt-toolkit.
Google Earth 4(beta) Running on Ubuntu 6.06
Google Earth 4(beta) Running on Ubuntu 6.06

Minimum System Requirements [7]:

* Kernel: 2.4 or later

* CPU: Pentium 3, 500 MHz
* System Memory (RAM): 128 MB
* Hard Disk: 400 MB free space
* Network Speed: 128 kbit/s
* Screen: 1024x768, 16 bit color
* Tested and works on the following distributions:
o Ubuntu 5.10/6.06/6.10
o SUSE 10.1/10.2
o Fedora Core 4/5/6
o Linspire 5.1
o Gentoo 2006.0
o Debian 3.1
o Red Hat 9
o Slackware 11.0
o FreeBSD 6.1/7.0 with Linux Emulation
o Arch Linux 0.7.2 Gimmick
o Xandros 3.0.3 Business Edition
o Mandriva 2007
o Sabayon Linux 3.26

[edit] Resolution and accuracy
The Isles of Scilly, showing the very low resolution of some islands. The islands (green area) are about 10 km across.
The Isles of Scilly, showing the very low resolution of some islands. The islands (green area) are about 10 km across.
The west side of Gibraltar, tilted view showing the sea rising up the Rock of Gibraltar - claimed height of the sea just off the beach at Elliots Memorial, 252 m.
The west side of Gibraltar, tilted view showing the sea rising up the Rock of Gibraltar - claimed height of the sea just off the beach at Elliots Memorial, 252 m.

Most land areas are covered in satellite imagery with a resolution of about 15 m per pixel. Some population centers are also covered by aircraft imagery (orthophotography) with several pixels per meter. Oceans are covered at a much lower resolution, as are a number of islands; most notably, Tórshavn, the capital of the Faroe Islands, and the Isles of Scilly off southwest England, are at a resolution of about 500 m or less. These pictures are provided by Terrametrics.

Place name and road detail vary greatly from place to place. They are most accurate in the USA and Europe, but regular mapping updates are improving coverage elsewhere.

Google has resolved many inaccuracies in the vector mapping since the original public release of the software, without requiring an update to the program itself. An example of this was the absence from Google Earth's map boundaries of the Nunavut territory in Canada, a territory that had been created on April 1, 1999; this mistake was corrected by one of the data updates in early 2006. Recent updates have also increased the coverage of detailed aerial photography, particularly in western Europe.

Cloud cover and shadows can make it difficult or impossible to see details in some land areas, including the shadow side of mountains.

The stars in the background are not random. Google Earth uses a real star map to render the background. [verification needed]

[edit] Inaccuracies

Google Earth is a complex application representing two and three dimensional data, vector data, integer and real numbers, and a variety of geometric projections. The imagery come from a variety of sources and the processing of the imagery is done both by machine and humans. In addition, there are many terabytes of information from a variety of sources involving many people. As a result, there are bound to be inaccuracies in the data. Google is continuously taking input and improving the existing data.
Greenland with an odd black line and cut off fire.
Greenland with an odd black line and cut off fire.

The images are not all taken at the same time, but are generally current to within three years. Image sets are sometimes not correctly stitched together. Updates to the photographic database can occasionally be noticed when drastic changes take place in the appearance of the landscape, like for example Google Earth's incomplete updates of New Orleans following Hurricane Katrina, or when placemarks appear to shift unexpectedly across the Earth's surface. Though the placemarks have not in fact moved, the imagery is composed and stitched differently. Such an update to London's photography in early 2006 created shifts of 15-20 metres in many areas, noticeable because the resolution is so high.

Errors sometimes occur due to the technology used to measure the height of terrain; for example, tall buildings in Adelaide cause one part of the city to be rendered as a small mountain, when it is in fact flat. The height of the Eiffel Tower creates a similar effect in the rendering of Paris.

The "Measure" function shows that the length of equator is about 40,030.24 km, giving an error of −0.112% compared with the actual value of 40,075.02 km Earth; for the meridional circumference, it shows a length of about 39,963.13 km, also giving an error of −0.112% compared with the actual value of 40,007.86 km.

The Arctic polar ice caps are completely absent from the current version of Google Earth. Information explaining this notable absence is difficult to find if any has been supplied at all. Google Earth presently renders no ice packs in the arctic circle, and the geographic North Pole is found hovering over the Arctic Ocean. There is very low resolution coverage of the Antarctic continent. The tiling system produces bizarre artifacts near the poles as the tiles become 'infinitely' small and rounding errors accumulate.

The atmosphere in Google Earth is greatly exaggerated. Comparisons with actual photographs show the Google Earth atmosphere to be 20 times thicker.

Where no 3 arc second digital elevation data was available, the three dimensional images covering some areas of high relief are not at all accurate, but most mountain areas are now well mapped. The underlying digital elevation model has been placed 3 arc seconds too far north and up to 3 arc seconds too far west. This means that some steep mountain ridges incorrectly appear to have shadows extending over onto their south facing sides. Some high resolution images have also been misplaced, an example is the image covering Annapurna, which is misplaced by about 12 arc seconds.

Occasionally links to Wikipedia show up in strange places - a link to Irkutsk appears at 52°17′00″N, 1°44′00″E. This may be due to an error, since corrected, in the original Wikipedia page that has not been updated on the Google Earth server.

[edit] National security and privacy issues
The United States Naval Observatory as seen through Google Maps. 38° 55′ 20" N 77° 4′ 0" W
The United States Naval Observatory as seen through Google Maps. 38° 55′ 20" N 77° 4′ 0" W

Critics have expressed concern over the willingness of Google to cripple their dataset to cater to special interests, believing that intentionally obscuring any land goes against its stated goal of letting the user "point and zoom to any place on the planet that you want to explore".

The software has been criticized by a number of special groups, including national officials, as being an invasion of privacy and even posing a threat to national security. The typical argument is that the software provides information about military or other critical installations that could be used by terrorists. The following is a selection of such concerns:

* The Indian president APJ Abdul Kalam has expressed concern over the availability of high-resolution pictures of sensitive locations in India.[5] Google subsequently agreed to censor such sites.[6]
* The Indian Space Research Organization has said Google Earth poses a security threat to India, and seeks dialogue with Google officials.[7]
* The South Korean government has expressed concern that the software offers images of the presidential palace and various military installations that could possibly be used by their hostile neighbor North Korea.[8]
* In 2006, one user spotted a large topographical replica in a remote region of China. The model is a small-scale (1/500) version of the Karakoram Mountain Range, currently under the control of China but claimed by India. When later confirmed as a replica of this region, spectators began entertaining sinister military implications.[9][10]
* Operators of the Lucas Heights nuclear reactor in Sydney, New South Wales asked Google to censor high resolution pictures of the facility.[11] However, they later withdrew the request.[12]

Blurred out image of the Royal Stables in The Hague, Netherlands.
Blurred out image of the Royal Stables in The Hague, Netherlands.

Some citizens may express concerns over aerial information depicting their properties and residences being disseminated freely. As relatively few jurisdictions actually guarantee the individual's right to privacy, as opposed to the state's right to secrecy, this is an evolving, but minor, point. Perhaps aware of these critiques, for a time, Google had Area 51 (which is highly visible and easy to find) in Nevada as a default placemark when Google Earth is first installed.

As a result of pressure from the United States government, the residence of the Vice President at Number One Observatory Circle is obscured through pixelization in Google Earth and Google Maps. The usefulness of this downgrade is questionable, as high-resolution photos and aerial surveys of the property are readily available on the Internet elsewhere. [8] Capitol Hill used to also be pixelized in this way but this was lifted.

[9]

In a working paper from Microsoft Research (How we watch the city) Danyel Fisher notes that the Microsoft map servers retain a record of all map tile requests. Fisher notes that "Tile server logs are standard IIS logs; they store an IP address, a date and times of access and a URL". It is likely that similar logging takes place in respect of Google's online maps. The implication of this is that all map views are traceable back to the viewer, and that viewing online maps is not an anonymous activity.

[edit] Google Earth Community

The Google Earth Community is an online forum [10] which is dedicated to producing placemarks of interesting or educational perspectives. It may be found on the Google Earth webpage or under the Help section on the program itself. After downloading a placemark, it will automatically run Google Earth (if not opened), and fly to the area specified by the person who placed it. Once there, you can add it to your "My Places" by right clicking on the icon and selecting "Save to My Places". Additionally, anyone can post a placemark for others to download; as long as you have an account.

[edit] Google Earth and Genocide Awareness

In 2007, Google Earth joined with United States Holocaust Memorial Museum to roll out Crisis in Darfur - an unprecedented mapping initiative that allows users to learn about and see the impact of the Darfur Conflict.[13] The feature allows Google Earth users to zoom in on satellite images of the Darfur area of Sudan. The feature also includes photos, data, and eyewitness accounts.

[edit] Copyright

Currently, every image created from Google Earth using satellite data provided by Google Earth is a copyrighted map. Any derivative from Google Earth is made from copyrighted data which, under United States Copyright Law, may not be used except under the licenses Google provides. Google allows non-commercial personal use of the images (e.g. on a personal website or blog) as long as copyrights and attributions are preserved[14].

By contrast, images created with NASA's globe software World Wind using Blue Marble, Landsat or USGS layer, each of which is a terrain layer in the public domain. Works created by an agency of the United States government are public domain at the moment of creation. This means that those images can be freely modified, re-distributed and used for commercial purposes.

[edit] Google Earth Plus

Google Earth can be upgraded to a "Plus" edition for a $20 annual subscription fee. Google Earth Plus is an individual-oriented paid subscription upgrade to Google Earth and adds the following features:

* GPS integration: read tracks and waypoints from a GPS device. Third party applications have been created which provide this functionality using the basic version of Google Earth by generating KML files based on user-specified waypoints [11]. However, these tools only work with specific GPS devices whereas Google Earth Plus provides support for the Magellan and Garmin product lines, who together hold a large share of the GPS market.
* Higher resolution printing.
* Customer support via email.
* Data importer: read address points from CSV files. A feature allowing path and polygon annotations, which can be exported to KML, was formerly only available to Plus users, but was made free in version 4.0.2416.

[edit] Google Earth Pro

For a $400 annual subscription fee, Google Earth Pro is a business-oriented upgrade to Google Earth that has more features than the "Plus" version. The Pro version includes add-on software such as movie making, GIS data importer and advanced printing modules. These used to cost extra in addition to the $400 fee but have recently been included free in the package. [12]

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