'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), which includes a few more features; and Google Earth Pro ($400 per annum), intended for commercial use.
[2]
Overview
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 release of Google Earth caused a more than tenfold increase in media coverage on
virtual globes between
2005 and
2006,
[3] driving public interest in
geospatial technologies and applications.
Denver,
Colorado, viewed in Google Earth, now almost completely modeled with high-quality 3D models.
The viewer will show 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
[4].
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 Digital elevation model|DEM]] data to fill the gaps in
SRTM coverage
[5]. 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 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 . 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 30th, 2007 that it is acquiring
Panoramio.
[11]
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''.
[12]
Specifications
Google Earth comes with atmosphere effects and seabed
★ 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.
[13]
★ 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 are usually less than 3 years old. The date next to the copyright information is often cited as the date the picture was taken, but this practice is incorrect.
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
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. 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, 4.1.7076.4558, released on
May 9,
2007, features, among other things, a new user interface and the option for Mac OS X users to upgrade to the "Plus" version.
[14] Some users reported difficulties with Google Earth crashing in the latest version when zooming in.
[15]
Linux version
Google Earth 4(beta) Running on
Ubuntu 6.06
Starting with the version 4 beta, Google Earth functions under
Linux, as a native port using the
Qt-toolkit.
;Minimum System Requirements
[16]:
★ 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
The
Isles of Scilly, showing the very low resolution of some islands. The islands (green area) are about 10 km across.
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 comes 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.
The west side of
Gibraltar, tilted view showing the sea rising up the
Rock of Gibraltar - claimed altitude 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.
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.
Greenland with an odd black line and cut off fire.
An error causing part of
Paris to appear as a hill due to the height of the
Eiffel Tower.
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 the 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 ft when Salton City is approx −200 ft; Death Valley is −286 ft; and the Dead Sea is −1,378 ft.
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.
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 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.
[17] Google subsequently agreed to censor such sites.
[18]
★ The
Indian Space Research Organisation has said Google Earth poses a security threat to India, and seeks dialogue with Google officials.
[19]
★ 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.
[20]
★ 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.
[21][22]
★ 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.
★
Morocco's main Internet provider
Maroc Telecom has been blocking Google Earth
[23] 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.
[24] However, they later withdrew the request.
[25]
★ 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[26].
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.
[27] 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".
Google Earth Community
The
Google Earth Community is an online forum
[28] 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 () or a burning car, on A3 autobahn near Gieslenberg, N of Leverkusen, Germany ().
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
[29].
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.
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
Many of Google Earth Plus's features can be added on for free with third-party software and utilities,
[30] including GPS, spreadsheet import, and geocoding.
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.
[31]
Flight Simulator
Google Earth's Flight Simulator over New York City
In Google Earth v4.2, a flight simulator was included as a
hidden feature.
[32]
★
Google Earth Flight Simulator Controls
It is also possible to control the simulator with a joystick, although not all models are currently supported.
See also
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
1. Available in English, Swahili, German, Dutch, French, Spanish, Italian and Japanese
2. Google Earth Product Family
3. Media Coverage of Geospatial Platforms
4. Google Earth Coverage: Maps showing a visual representation of Google Earth coverage
5. Google Earth Community: Nov. 23rd - Thanksgiving Day imagery update
6. http://www.skyscrapernews.com/googleearth.php
7. http://www.infopot.tk
8. http://sketchup.google.com/3dwarehouse/
9. Explore the sky with Google Earth
10. http://technology.newscientist.com/article/dn12523
11. Google is planning to acquire Panoramio
12. Avi Bar-Ze’ev (from Keyhole, the precursor to Google Earth) on origin of Google Earth
13. http://www1.webng.com/azimuthal/earth_proj.html
14. Google Earth 4.2.180.1134 - MacUpdate
15. Google Earth Community: Viewing forum: Google Earth for Mac OS X
16. http://earth.google.com/download-earth.html
17. "Kalam Concerned Over Google Earth"
18. "Google Earth agrees to blur pix of key Indian sites"
19. "Google Earth Poses Security Threat to India, ISRO Chief seeks Dialogue"
20. "Google Earth images compromise secret installations in S. Korea"
21. "Chinese X-file excites spotters"
22. "From sky, see how China builds model of Indian border 2400 km away"
23. Message au monde - Message to the world
24. "Google Earth prompts security fears"
25. " Aussie Nuclear Reactor on Google Earth"
26. "New Chinese Ballistic Missile Submarine Spotted"
27. Eyeballing the US Vice Presidential Residence
28. http://bbs.keyhole.com/ubb/ubbthreads.php/Cat/0
29. Google Earth Help Center: Can I post images to the web?
30. http://freegeographytools.com/?p=25
31. Which version of Google Earth is right for you?
32. http://marco-za.blogspot.com/2007/08/google-earth-flight-simulator.html
★
The Whole Earth, Cataloged, , Evan, Ratliff, Wired,
External links
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
★
(unofficial) Google Earth Blog - Google Earth news and tips.
★
German Google Earth Community - The German Google Earth community with lots of placemarks
★
Chinese Google Earth Forum - The Chinese Google Earth community which named 'Gukeluntan'
★
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 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
★
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
★
Google Earth Basics
★
Google Earth Linux instruction
★
World's KML file - you can download
★
Google Sightseeing - blog of interesting and unusual sights
★
Very large collection of KML databases
Tools
★
KaMeLwriter - Uses hierarchical maps (
Mind maps) to create and manage KML files.
★
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.
★
Google Earth Toolbox - A set of
Matlab plotting/drawing functions with KML output.
★
TrailRunner - Editor for workout or hiking tracks, imports and exports KML files.
★
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.
Reviews
★
Comparison with NASA World Wind
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