Google Earth

Un article de Vev.

Modèle:Infobox software2 Google Earth is a virtual globe program that was originally called Earth Viewer and was created by Keyhole, Inc. It maps the earth by the superimposition of images obtained from satellite imagery, aerial photography and GIS 3D globe. It is available under three different licenses: Google Earth, a free version with limited functionality; Google Earth Plus ($20 per year), which includes additional features; and Google Earth Pro ($400 per year), which is intended for commercial use.<ref name="Google Earth Product Family"> Google Earth Product Family

. Retrieved on 2007-08-05. </ref>

Overview

Formerly known as Earth Viewer, Google Earth was developed by Keyhole, Inc., a company acquired by Google in 2004. The product, renamed Google Earth in 2005, 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 release of Google Earth caused a more than tenfold increase in media coverage on virtual globes between 2005 and 2006,<ref name="Media Coverage of Geospatial Platforms"> Media Coverage of Geospatial Platforms

. Retrieved on 2007-08-05. </ref> driving public interest in geospatial technologies and applications.

The viewer displays 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.<ref>Google Earth Coverage: Maps showing a visual representation of Google Earth coverage</ref> 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 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.<ref> Google Earth Community: Nov. 23rd - Thanksgiving Day imagery update

.</ref>

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 able to show all kinds of images overlaid on the surface of the earth and is also a Web Map Service client. Google Earth supports managing three-dimensional Geospatial data through Keyhole Markup Language (KML).

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) those in the United States, Canada, Ireland, India, Japan, United Kingdom,<ref>http://www.skyscrapernews.com/googleearth.php</ref> Germany, Pakistan and the cities, Amsterdam and Alexandria.<ref>http://www.infopot.tk/</ref> In August 2007, Hamburg became the first city entirely shown in 3D, including textures such as facades. Three-dimensional renderings are available for certain buildings and structures around the world via Google's 3D Warehouse<ref>http://sketchup.google.com/3dwarehouse/</ref> and other websites.

Sky mode

In version 4.2, released August 22, 2007, Google Earth added a Sky tool for viewing stars and astronomical images.<ref> Explore the sky with Google Earth

. Google 
 
 (2007-08-22)
   

. Retrieved on 2007-08-22. </ref> Google Sky is produced by Google through a partnership with the Space Telescope Science Institute in Baltimore, the science operations center for Hubble. Dr. Alberto Conti and his co-developer Dr. Carol Christian of the Space Telescope Science Institute, plan to add the public images from 2007,<ref>http://technology.newscientist.com/article/dn12523</ref> as well as color images of all of the archived data from Hubble's Advanced Camera for Surveys. Newly released Hubble pictures will be added to the Google Sky program as soon as they are issued. New features such as multi-wavelength data, positions of major satellites and their orbits as well as educational resources will be provided to the Google Earth community and also through Christian and Conti's website for Sky. Also visible on Sky mode are constellations, stars, galaxies and animations depicting the planets in their orbits. A real-time Google Sky mashup of recent astronomical transients, using the VOEvent protocol, is being provided by the VOEventNet collaboration.

Wikipedia and Panoramio integration

In December 2006 Google Earth added a new layer called "Geographic Web" that includes integration with Wikipedia and Panoramio. In Wikipedia, entries are scraped for coordinates via the Modèle:Srlink. 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. Google announced on May 30, 2007 that it is acquiring Panoramio.<ref> Google is planning to acquire Panoramio

. google.com  
 

 

.</ref>

Influences

The Google Earth interface bears a noted similarity to the ‘Earth’ program described in Neal Stephenson’s sci-fi classic Snow Crash. Indeed, a Google Earth co-founder claimed that Google Earth was modeled after Snow Crash, while another co-founder said it was inspired by Powers of Ten.<ref name="google_earth1">Avi Bar-Ze’ev (from Keyhole, the precursor to Google Earth) on origin of Google Earth</ref>

Specifications

• Coordinate System and Projection
  • The internal coordinate system of Google Earth is geographic coordinates (latitude/longitude) on the World Geodetic System of 1984 (WGS84) datum.
  • 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.<ref>http://www1.webng.com/azimuthal/earth_proj.html</ref>
• Baseline resolutions
  • U.S.: 15 m (some states are completely in 1 m or better)
  • Germany, Switzerland, Netherlands, Denmark, England, Andorra, Luxembourg, Liechtenstein, San Marino, Vatican City: 1 m or better
  • Global: Generally 15 m (some areas, such as Antarctica, are in extremely low resolution), but this depends on the quality of the satellite/aerial photograph uploaded.
• Typical high resolutions
  • U.S.: 1 m, 0.6 m, 0.3 m, 0.15 m (extremely rare; e.g. Cambridge and Google Campus, or Glendale)
  • Europe : 0.3 m, 0.15 m (e.g. Berlin, Zürich, Hamburg)
• Altitude resolution:
  • Surface: varies by country
  • Seabed: Not applicable (a colorscale approximating sea floor depth is "printed" on the spherical surface).
• Age: Images dates vary. The image data can be seen from squares made when Digital Coverage is enabled. The date next to the copyright information is not the correct image date. Zooming in or out could change the date of the pictures. Most of the international urban image dates are from 2004 and have not been updated. However, most US images are kept current.

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 kb/s
• 16MB 3D-capable graphics card
• Resolution of 1024x768, 16-bit High Color
• Windows XP or Windows 2000 (not Windows ME compatible), 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.

Mac 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, 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 version 10.4 or later. 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.

From version 4.1.7076.4558 (released on May 9, 2007) onward, Mac OS X users can now, among other new features, upgrade to the "Plus" version via an option in the Google Earth menu.<ref> Google Earth 4.2.180.1134 - MacUpdate

.</ref> Some users reported difficulties with Google Earth crashing in the latest version when zooming in.<ref> Google Earth Community: Viewing forum: Google Earth for Mac OS X

.</ref>

Linux version

Starting with the version 4 beta, Google Earth functions under Linux, as a native port using the Qt-toolkit. It is proprietary software specifically in order to impose Digital Restrictions Management, and the Free Software Foundation consider one of the High Priority Free Software Projects to develop a free compatible client for Google Earth.

Minimum System Requirements<ref>http://earth.google.com/download-earth.html</ref>

• Kernel: 2.4 or later
• CPU: Pentium III, 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:

Resolution and accuracy

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; notably, the Isles of Scilly off southwest England, are at a resolution of about 500 m or less. These pictures are provided by Terrametrics.

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 certain areas of western Europe, though not including Ireland where imagery remains extremely limited.

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.

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

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. Also, elevations below sea level are presented as sea level; i.e. Salton City, California; Death Valley; and the Dead Sea are all listed as 0 m when Salton City is −38 m; Death Valley is −86 m; and the Dead Sea is −420 m.

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. Elevation data was recently updated to 10-meter (1/3-arc-second) resolution for much of the United States from the previous 30-meter (1-arc-second) resolution.

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, as are waves in the oceans. The geographic North Pole is found hovering over the Arctic Ocean. There is very low resolution coverage of the Antarctic continent (1m resolution images of some parts of Antarctica were added in June 2007 for the first time). The tiling system produces artifacts near the poles as the tiles become 'infinitely' small and rounding errors accumulate.

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

National security and privacy issues

The software has been criticized by a number of special interest 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:

• Former Indian president APJ Abdul Kalam has expressed concern over the availability of high-resolution pictures of sensitive locations in India.<ref name="IndianPresCrit"> "Kalam Concerned Over Google Earth"

. Retrieved on 2007-01-25. </ref> Google subsequently agreed to censor such sites.<ref> "Google Earth agrees to blur pix of key Indian sites"

.</ref>

• The Indian Space Research Organisation has said Google Earth poses a security threat to India, and seeks dialogue with Google officials.<ref name="ISROCrit"> "Google Earth Poses Security Threat to India, ISRO Chief seeks Dialogue"

. Retrieved on 2007-01-25. </ref>

• 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.<ref name="SouthKoreaGovCrit"> "Google Earth images compromise secret installations in S. Korea"

. Retrieved on 2007-01-25. </ref>

• 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 military implications.<ref name="SMHChinaModel"> "Chinese X-file excites spotters"

. Retrieved on 2007-01-25. </ref><ref name="IndianExpressChinaModel"> "From sky, see how China builds model of Indian border 2400 km away"

. Retrieved on 2007-01-25. </ref>

• The Area 51 base in the Nevada desert is clearly visible, with no evidence of intentional obstruction or blurring. The base's runways and even a number of planes are visible, but sources confirm that the government has knowledge of all nearby photography satellites, and personnel are instructed to cover any vital technology and stay within the buildings at all times when one is within range.^{[citation needed]}
• Morocco's main Internet provider Maroc Telecom has been blocking Google Earth<ref>Message au monde - Message to the world</ref> since August 2006 without giving any justification for it.
• Operators of the Lucas Heights nuclear reactor in Sydney, New South Wales asked Google to censor high resolution pictures of the facility.<ref name="ABCAUNukeFears"> "Google Earth prompts security fears"

. Retrieved on 2007-01-25. </ref> However, they later withdrew the request.<ref name="SearchViewsAussieNukeReqDropped"> " Aussie Nuclear Reactor on Google Earth"

. Retrieved on 2007-01-25. </ref>

• In July 2007, it was reported that a new Chinese navy Jin-class nuclear ballistic missile submarine was photographed at the Xiaopingdao Submarine Base south of Dalian.<ref> "New Chinese Ballistic Missile Submarine Spotted"

. Retrieved on 2007-07-10. </ref>

• In October 2007, The Guardian reported that al-Aqsa Martyrs' Brigades were using Google Earth to plan Qassam rocket attacks on Israel.<ref>Inside Gaza: 'Resistance is our strategy'</ref>

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^{[citation needed]}, 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.<ref> Eyeballing the US Vice Presidential Residence

.</ref> Capitol Hill used to also be pixelized in this way but this was lifted.

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".

Finally, empirical research has shown that while Google does allow people to opt-out from personal listings, a vast majority of people can still be geographically located using phone numbers. <ref> "The Creative Reconstruction of the Internet: Google and the Privatization of Cyberspace and DigiPlace"

.</ref>

Google Earth Community

The Google Earth Community is an online forum<ref>http://bbs.keyhole.com/ubb/ubbthreads.php/Cat/0</ref> 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.

Google earth also can be used to locate "disasters". Currently a user can find these items within the google earth community. An example is a capsized ship off the shore (Modèle:Coord) or a burning car, on A3 autobahn near Gieslenberg, N of Leverkusen, Germany (Modèle:Coord).

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.<ref>Google Earth Help Center: Can I post images to the web?</ref> By contrast, images created with NASA's globe software World Wind use the 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.

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. A variety of third party applications have been created which provide this functionality using the basic version of Google Earth by generating KML or KMZ files based on user-specified or user-recorded waypoints. However, Google Earth Plus provides direct support for the Magellan and Garmin product lines, which together hold a large share of the GPS market. The Linux version of the Google Earth Plus application does not include any GPS functionality.
• Higher resolution printing.
• Customer support via email.
• Data importer: read address points from CSV files; limited to 100 points/addresses. 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.
• Higher data download speeds

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.
• Advanced printing modules.

These used to cost extra in addition to the $400 fee but have recently been included in the package.<ref> Which version of Google Earth is right for you?

.</ref>

Flight Simulator

In Google Earth v4.2, a flight simulator was included as a hidden feature. It can be accessed by holding Control+Alt+A or Control+A at the same time. After this feature has been activated at least once it appears under the tools menu. As of right now there are only 2 different aircraft that can be used, in addition to a few airports.<ref>http://marco-za.blogspot.com/2007/08/google-earth-flight-simulator.html</ref>

• Google Earth Flight Simulator Controls

It is also possible to control the simulator with a joystick, although not all models are currently supported.

Google Earth in Popular Culture

• Google Earth is regularly shown in the TV programme Dog The Bounty Hunter, when a certain felons house or other location is shown.
• Google Earth is used by news channels such as the BBC, CNN, Citytv, ESPN, Fox News, and The Weather Network.

See also

• Google Maps
• Google Mars
• Google Moon

Related information

• Web mapping
• Geoweb
• NASA World Wind
• Yinchuan - subject to an Internet phenomenon originating on Google Earth forum.

Google mapping services

• List of Google services and tools
• Google Maps
  • Google Moon
  • Google Mars

Other providers

• DigitalGlobe — the provider of high resolution imagery to Google Earth
• EarthSat
• GeoEye
• GlobeXplorer
• Pictometry
• Spot Image
• ViewGL - updated aerial imagery for Google Earth

References

External links

Modèle:Linkfarm Modèle:GeoGroupTemplate

Official and related sites

• Official Google Earth Website - Download software from here
• Official Google Earth User blog - Weblog of John Gardiner, a technical writer with Google Earth
• Ogle Earth - Google Earth news: Charting innovative uses and political implications of Google Earth
• Google Earth Wereld - The Dutch Google Earth site with cool placemarks
• KugelErde - German Google Earth site with lots of placemarks

Placemarks and overlays

• Google Earth Hacks - A huge collection of files for use with Google Earth
• Google Earth Library - Interesting things to do with Google Earth
• TierraWiki: Exposes a network link for a digital trail database for outdoor activities.
• Wikipedia Articles for Google Earth - Mapping 80,000 entries from WP:GEO
• gCensus Project - Stanford University application to map US Census data
• Climate Change MediaWatch - KML file of news articles
• GoogleEarthFindr - Custom Search Engine for Placemarks and Overlays

Unofficial guides and tips

• (unofficial) Google Earth Blog - Google Earth news and tips.
• Google Earth Linux instructions
• World's KML file - downloadable
• Google Sightseeing - blog of interesting and unusual sights
• Very large collection of KML databases
• STScI's community contributions to Sky website
• Geofumadas- tips about Google Earth and CAD/GIS.

Tools

• Batch Geocoder - Generate a KML file from an address list, works with any tabular data source.
• CommunityViz - ArcGIS extension illustrates possible future development patterns over time. See also the CommunityViz article.
• C_GPS2KML - Generate KML from GPS logs with extended features.
• GEgpsd - Cross-platform python script allowing real-time GPS tracking from any NMEA device.
• GeoServer - Server to generate KML from Shapefiles, ArcSDE, Oracle, PostGIS, MySQL, GeoTiff, ArcGrid, with support for Network links, superoverlays, time and custom pop-ups.
• Google Earth Toolbox - A set of Matlab plotting/drawing functions with KML output.
• KaMeLwriter - Uses hierarchical maps (Mind maps) to create and manage KML files.
• perl-Geo-GoogleEarth-Document - Perl object library to generate Google Earth KML Documents
• TrailRunner - Editor for workout or hiking tracks, imports and exports KML files.

Reviews

• Comparison with NASA World Wind

Modèle:Google Inc. Modèle:Earthar:جوجل إيرث cs:Google Earth da:Google Earth de:Google Earth es:Google Earth fa:گوگل ارت fr:Google Earth ka:Google Earth ko:구글 어스 hr:Google Earth id:Google Earth it:Google Earth he:Google Earth km:Google Earth lt:Google Earth hu:Google Earth ms:Google Earth nl:Google Earth ja:Google Earth no:Google Earth nn:Google Earth pl:Google Earth pt:Google Earth ro:Google Earth ru:Google Планета Земля sq:Google Earth sk:Google Earth fi:Google Earth sv:Google Earth ta:கூகுள் எர்த் th:กูเกิลเอิร์ธ tg:Google Earth tr:Google Earth uk:Google Earth yi:גוגל ערד zh:Google地球