article

Google Earth is a free-of-charge, downloadable virtual globe program. It maps the entire earth by pasting images obtained from satellite imagery, aerial photography and GIS over a 3D globe.

Overview

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

Many large cities are available in a resolution high enough to see individual buildings, houses, and even cars. In cities such as London and Washington DC, individual people can be clearly discerned. The degree of resolution available is based somewhat on the points of interest, but all land is covered in at least 15 meters of resolution. Cambridge, MA and Fulton County, NY have the highest resolution, at six inches. Google Earth allows users to search for addresses (for the USA, Canada, and Europe only), enter coordinates, or simply use the mouse to browse to a location.

Google Earth also has digital terrain model 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. In addition, Google has provided a layer allowing one to see 3D buildings for some major cities in the US.

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 is available in a free version, and in licensed versions for commercial use. It is currently officially available on Windows XP, Mac OS X and Linux. A leaked version of working non-public beta of Google Earth for Mac OS X started to appear on the internet on December 8 2005. However, it was recently affirmed by Google at the 2006 National Educational Computing Conference that schools cannot install Google Earth onto their computers as it is a violation of the end user agreement. The end user agreement clearly states "The Software is made available to you for your personal, non-commercial use only. You may not use the Software or the geographical information made available for display using the Software, or any prints or screen outputs generated with the Software in any commercial or business environment or for any commercial or business purposes for yourself or any third parties."

When started up, Google Earth's view is centered on Lawrence, Kansas. The director of engineering for Google Earth is Brian McClendon, whose online biography says he is a 1986 graduate of the University of Kansas. * This default view could also be due to the fact that Lawrence, Kansas represents a location very close to the exact center of the contiguous United States.

See also KML (Keyhole Markup Language).

3D Buildings

A feature implemented by Google after its acquisition of Keyhole is a 3D dataset for (as of June 2006) 38 US cities.This data is provided by Sanborn [http://www.sanborn.com/products/citysets.htm Citysets. This feature is limited to displaying grey overlaying "blocky" buildings. On March 14, 2006, Google acquired @Last Software, makers of SketchUp, who had created a plugin for 3D renderings in Google Earth.

The cities currently included are only from the United States. However, 3D buildings are available for certain buildings around the world using programs from other websites. The cities include: New York City (Manhattan below Central Park and West Brooklyn), Chicago (the Loop, near Magnificent Mile, and residential areas north, south, and just west of those areas along the lake), Los Angeles (downtown, areas along the Miracle Mile, Wilshire Blvd), Honolulu (downtown and along the beach), San Francisco (the northeastern quadrant), Philadelphia (downtown and residential areas to the south and west), Houston (downtown), Washington, Boston, Dallas, Minneapolis, Saint Paul, Miami, Atlanta, Denver, Seattle, Detroit (downtown), Arlington, Baltimore, St. Louis (downtown), Pittsburgh, Cleveland, San Diego, Long Beach, Sacramento, Cincinnati, Tampa, Fort Lauderdale, New Orleans, Kansas City, Buffalo, Portland, Las Vegas, Jersey City (along the Hudson River), Newark, Memphis, Phoenix, and St. Petersburg, Florida, USA.

Specifications

  • Coordinate System
    • Data is stored and presented using the standard WGS84 datum.
  • Baseline resolutions
    • U.S.: 15 m
    • Global: Generally 15 m (some areas such as certain oceanic islands are in extremely low resolution).
  • Typical high resolutions
    • U.S.: 1 m, 0.6 m, 0.3 m, 0.15 m (extremely rare; e.g. Cambridge, Ma. and Google Campus)
    • Global:
  • Altitude resolution:
    • Surface:
    • Seabed: Not applicable (the seabed is "printed" on the spherical surface).
  • Age: Usually less than 3 years old. (For example, the image area around Taipei 101 shows the building before the red construction elevators were removed in 2004.)

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 with 16 MB of Video RAM
  • 1024x768, "16-bit High Color" screen

The most likely mode of failure is insufficient video RAM: the software is designed to declare failure if 32 MB of video RAM is not available. 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. Compare the resolution of these older B&W data:

  • http://terraserver-usa.com/image.aspx?T=1&S=10&Z=17&X=3284&Y=20743&W=1

versus what is currently available with Google Earth in color:

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 implimented as Image Overlays, onto of Google Earth - allowing the user to combine the higher (in some cases) resolution imagery from TerraServer over the smoother Google Earth program.

Mac OS X Version

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, a pretty sure sign that the 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. Fullscreen mode does not work. There are a few bugs concerning the menu bar when switching between applications. There are a few bugs concerning annotation balloons and printing.

The latest version is 4.0.1694 released on July 17, 2006, is currently available as a beta version and features amongst others a new user interface and the option for Mac OS X users to upgrade to the "Plus" version. *.

Linux Version

Google Earth 4(beta)is now available under Linux. Google has taken the position that it will attempt to make Google Earth compatible with all mainstream distributions [http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/449590/page/0/vc/1.

Minimum System Requirements* :

  • Kernel: 2.4 or later
  • glibc: 2.3.2 w/ NPTL or later
  • XFree86-4.0 or x.org R6.7 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 OSs:
    • Ubuntu 5.10
    • Suse 10.1
    • Fedora Core 4/5
    • Linspire 5.1
    • Gentoo 2006.0
    • Debian 3.1
    • Red Hat 9
    • FreeBSD 6.1/7.0 with Linux Emulation

Accuracy

Most land areas are covered in satellite imagery with a resolution of about 15m per pixel, and some population centers are also covered in aircraft imagery (orthophotography) of several pixels per meter. Oceans are covered in much lower resolution.

Due to the limited spatial resolution of the altitude map, altitudes are often inaccurate, especially the altitude of small features, like mountain tops; e.g. Mount Everest's height is short by 253m, and the sea near Gibraltar is shown with an altitude of 252m.

Unlike the satellite images, the orthophotography has a perspective from close to the surface, leading to distortions when used in a mosaic. Tall buildings sometimes appear to be leaning towards each other (conspicuous in e.g. Chicago at South Clark Street, in the middle of downtown; or near the Empire State building in New York City). The Fatih Sultan Mehmet Bridge on the Bosporus may be another example of this effect. However, this effect is inevitable with any source of aerial photography, and is present in Getmapping's imagery of England and Wales, and the providers of much of the detailed photography have processed the images so that the joins are as seamless as possible.

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 of the Nunavut territory in Canada, an area comparable in size to Western Europe. Google Earth's map boundaries of Northern Canada showed only the Northwest Territories, not the division of Nunavut created on April 1 1999. This inaccuracy 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. Yet aeroplanes that were in flight as the pictures were taken are clearly visable - a prime example being a plane flying over the Devils Punch Bowl, Hindhead, Surrey, UK that dramatically blocks the view.

Place name and road detail vary greatly from place to place, and are most accurate in the USA and Europe, although regular mapping updates tend to improve this. Also, the North and South Poles are marked as 89°59'60" N and 89°59'60" S respectively, rather than the correct 90°00'00" N and 90°00'00" S.

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 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.

The stars are not random. Google Earth uses the real star map to render to background. http://cyber.lamost.org/?p=23

Criticisms

US bias

The software, in particular the search engine, is criticised for its US-bias; for example, entering in searches for "Birmingham" and for "St. Petersburg" bring up US cities, as opposed to the original and larger cities of those names (in the UK and Russia respectively). Although major cities throughout the world, such as Delhi, London, Rome, Berlin, Beijing, Toronto, and Sydney to name a few can just be typed into the search bar without the country name, most places outside of the US cannot be found with the search function unless the country name is added and written out in full (except for "UK" and "MX"), while there are many easier paths to find data for US locations.

The default setting is to U.S. customary units, despite metric units being the international standard officially adopted by every nation but 3 (the U.S, Liberia, and Myanmar, although Liberia and Myanmar use it in practice), leading to accusations of cultural imperialism. Critics assert that while the units can be changed, they should be set to metric by default, as well as pointing out that the 3D buildings feature is also limited at present to major US cities. Others counter that, as an American creation by a predominantly US-based corporation, it is Google's right to give preference to that country. Additionally, the last three major image updates have focused on Paris, the United Kingdom and Germany.

Google has also admitted problems with the software on systems using non-ASCII characters, for example, Chinese or Japanese.*

Need for updates after natural disasters and events

With the exception of some key cities and geographical areas on the planet, the images of many other areas are more than two years old and is thus, partly inaccurate information. While it may be time consuming and costly to update the images as a whole very often, the images are not being updated after major disasters like the Indian Ocean Tsunami of December 26, 2004, which altered coastlines and islands in several places across the Indian Ocean. Many coastal towns and villages across the region are very different, as of July 2006.

Naming disputes

Google Earth, under "alternate place names," includes "Jerusalem" and "Yerushalayim" but does not include the Arabic name for the city, Al Quds. East Jerusalem has been occupied by Israel since 1967, and its status is disputed. (see also: Positions on Jerusalem)

Some South Korean users have been angered by the fact that Google Earth and Google Maps use Japanese names for bays along the southeastern coast of the Korean Peninsula . Examples include bays near Busan (labelled Nakutogu Po and Kanrai ho), Masan (labelled Masan Ko, Kisan-ko, and Unchen Wan), and Goseong (labelled Kojo-wan, Toto wan, Nan Wan, and Toei kawan).

The software was criticized by Taiwanese users because the island was labelled as a province of mainland China. This has since been changed, but the change has angered the People's Republic of China *.

Google Earth confuses towns in Poland and Germany: Jelenia Gora in Poland is incorrectly referred to as Hirschberg, whereas Görlitz on the west side of the border is called Zgorzelec, the name of its Polish neighbour.

National security and privacy issues

The software has been criticised by a number of 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:

Additionally some citizens, particularly the rich or famous, as well as victims or perpetrators of crime, may have concerns over aerial information depicting their properties and residences being diseminated 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 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.

Google Earth Community

The Google Earth Community is an online forum * which is dedicated to produce 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.

Google Earth Plus

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. 3rd 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 *. 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.
  • Annotation – adds draw/sketch tools for richer annotations (can be shared as KML).
  • Data importer – read address points from CSV files.

Google Earth Pro

Google Earth Pro is a business-oriented paid upgrade to Google Earth that has more features than the "Plus" version. The Pro version is capable of running additional add-on software *.

References

See also

External links

Community and placemarks

Unofficial guides and tips

Addons

Games

Tools

  • IP locator on Earth
  • Google Earth Tools Google Earth Developer Tools and References
  • Google Earth World Gazetteer Searchable world gazetteer, direct Google Earth links to each place.
  • Batch Geocoder Generate a KML file from an address list, works with any tabular data source.
  • Placeopedia - A website that provides a way to link wikipedia articles with place points in Google Earth
  • Marrying maps to data for a new web service by John Markoff (Free NY Times registration required)
  • csv2map csv to Google Earth and Google Maps api batch server converter by Pivari.com (shareware)
  • RoboGEO Display geocoded photos and GPS tracklogs in Google Earth
  • KMLer ESRI ArcGIS 9 Extension to create intricate Google Earth KML files from ArcGIS content
  • TypeConvert ESRI ArcGIS 9 Extension to create intricate Google Earth KML files from ArcGIS feature classes
  • ARC2EARTH by Brian Flood, ArcGIS to Google Earth converter with emphasis on converting much of the rich map annotations from ArcGIS to KML

Reviews

Other

Google | Mac OS software | Windows software | Virtual globes | Backpacking

Google Earth | Google Earth | Google Earth | Google Earth | Google Earth | Google Earth | 구글 어스 | Google Earth | גוגל ארת' | Google Earth | Google Earth | Google Earth | Google Earth | Google Earth | Google Earth | Google Earth | Google Earth | Google Earth | Google Earth | கூகுள் எர்த் (Google Earth) | กูเกิลเอิร์ธ | Google Earth | Google Earth

 

This article is licensed under the GNU Free Documentation License. It uses material from the "Google Earth".

Home Page • arts • business • computers • games • health • hospitals • home • kids & teens • news • physicians • recreation• reference • regional • science • shopping • society • sports • world