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, Washington DC, and Seattle, 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.
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 1986University 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.
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 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), HonoluluSan Fransisco (the northeastern quadrant), PhiladelphiaHouston (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, Cincinati, 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.
- 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)
- Altitude resolution:
- 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 and the new WAPA Path 15 power line is still under construction (also 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:
versus what is currently available with Google Earth in color:
- Maps and aerial photos
- WikiSatellite view at WikiMapia
- Street map from MapQuest or Google Local
- Topographic map from TopoZone
- Aerial image or topographic map from TerraServer-USA
- Satellite image from Google Maps or Microsoft Virtual Earth.
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.
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 versions10.4 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.
link title==Linux Version== Starting with the version 4 beta, Google Earth functions under Linux. However, it is not a native application; instead, it is run through a WINE layer. Google has taken the position that it will attempt to make Google Earth compatible with all mainstream distributions.
Minimum System Requirements :
- 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 OSs:
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(orthophtography) 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 visible - a prime example being a plane flying over the Devil's 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 "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; 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 stars in the background are not random. Google Earth uses a real star map to render the background.
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). Fortunately, in Google Earth 4 (beta), more major cities can be found without typing in the country name (eI: Melbourne, Singapore, Shanghai, Cairo, Cape, Town, Colegne (Köln), Lima, and Jerusalem). Still, some places outside of the US can't be found with the search function unless the country name is added and written out in full (except for "UK" and "MX"), while you can simply abbreviate states 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 three (the U.S, Liberia, and Myanmar, although Liberia and Myanmar use metric in practice). 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, Google Earth has recently had their largest update of earth imagery, making at least 33% of land covered by satellite images.
Some South Korean users have been angered by the fact that Google Earth and Google mapsKorean 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). use Japanese names for bays along the southeastern coast of the
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 Gorlitz on the west side of the border is called Zgorzelec, the name of its Polish neighbour.
Google Earth, under "alternate place names," includes "Jerusalem" and "Yerushalayim" but does not include the Arabic name for the city, "Al Quds".
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:
- The Indian president APJ Abdul Kalam has expressed concern over the availability of high-resolution pictures of sensitive locations in India.
- 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 neighbour North Korea.
- Operators of the Lucas Heights nuclear reactor in Sydney, Australia asked Google to censor high resolution pictures of the facility. However, they later withdrew the request.
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 (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 PresidentNumber One Observatory Circle is obscured through pixelization in Google Earth and Google Maps.at
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; as long as you have an account.
Google Earth Plus
Google Earth can be upgraded to a "Plus" edition for $20. 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.