google earth

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), 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.

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.^{citation needed]}Las Vegas, NV, 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. See also Keyhole Markup Language (KML).

Using Google Earth

Google Earth is designed for complete ease and efficiency. It has a short tutorial on how to use it and a control panel below the main window.

Controls

Zooming

As well as the control panel, Google earth can be operated using the mouse and keyboard. Double clicking on a location causes the camera to zoom in on the spot. The mouse roller can also be used for zooming in and out and the plus and minus keys work as well on some versions.

Moving

The viewing window can be moved left, right, up and down as well as diagonal by clicking a location with the mouse and the moving the cursor in the opposite direction to that in which you want to go. The arrow keys also allow you to move. The left key moves left, the right key moves right and so on. However, Using the keyboard does not move you as quickly as the mouse does. The final way of moving is to search for a location or post code in the search box in the top left corner or clicking on one of the pre-set locations.

Panning

Google earth also allows you to move higher and lower and to rotate the camera. This can be done by clicking and dragging with the right mouse button or using the <, >, pg. up and pg. down keys.

Searching

Global Search

The box in the top left of the screen allows you to search for any location on earth quickly and pain free, just type in the place you want to see and press play to have the camera go straight there. For a more precise search, type in the place followed by its approximate location i.e. Las Vegas, USA

Local Search

Google Earth also allows you to search your local area for something, eg a dentist. NB It may require confirmation of the area you want to search. If so, enter a postcode.

3D Buildings

A feature implemented by Google after its acquisition of Keyhole is a 3D dataset for (as of September 2006) 38 US cities.[1] 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, in a recent update, the entire country of Japan is in 3D. [2] The data for the 3D buildings in Japan is from ZENRIN. The cities in the United States 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, Texas, Baltimore, St. Louis (downtown), Pittsburgh, Cleveland, San Diego, Long Beach, Sacramento, Cincinnati, Tampa, Fort Lauderdale, Kansas City, New Orleans, Buffalo, Portland, Las Vegas, Jersey City (along the Hudson River), Newark, Memphis, Phoenix, and St. Petersburg, Florida, USA. Also, 3D buildings are available for certain buildings around the world using programs from other websites.

See also Google Earth London under development

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 (a colorscale approximating seafloor depth 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:

• 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:

• Maps and aerial photos Coordinates: 37.4738° -79.2263°
  • 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 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. There are a few bugs concerning annotation balloons and printing.

The latest version, 4.0.1694, released on July 17, 2006, is currently available as a beta version and features, among other things, a new user interface and the option for Mac OS X users to upgrade to the "Plus" version. [3].

Linux version

Starting with the version 4 beta, Google Earth functions under Linux, as a native port using the Qt-toolkit.

Minimum System Requirements[4] :

• 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:
  • Ubuntu 5.10/6.06
  • SUSE 10.1
  • Fedora Core 4/5
  • Linspire 5.1
  • Gentoo 2006.0
  • Debian 3.1
  • Red Hat 9
  • Slackware 10.2
  • FreeBSD 6.1/7.0 with Linux Emulation
  • Arch Linux 0.7.2 Gimmick

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. 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.^{citation needed]} 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.

Many of the images also appear to be out of date. For example, based on the scale of new development, Milton Keynes in the UK is at least six years out of date. New applications, such as ViewGL, were developed to address this situation. However, again, the application only covers the USA.

Errors sometimes occur due to the technology used to measure how tall terrain is to create the effect of mountains in 3D, such as tall buildings in Adelaide being mistaken for a small mountain, instead of being rendered flat like it should be.

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.

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 [5]; 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. ^[1]

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). However Google Earth 4 (beta), more major cities can be found without typing in the country name (eg: Melbourne, Singapore, Shanghai, Cairo, Cape Town, Cologne (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. 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 and Japanese 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.

Google has also admitted problems with the software on systems using non-ASCII characters, for example, Chinese or Japanese.[6]

Naming disputes

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 [7]. 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 [8].

Google Earth came under heavy fire from the Indian Media when it showed the disputed region of Kashmir to be a province of Pakistan.

Google Earth confuses towns in Poland and Germany: Jelenia Gora in Poland is incorrectly referred to as Hirschberg. Google Earth, under "alternate place names," includes "Jerusalem" and "Yerushalayim" but does not include the Arabic name for the city, "Al Quds".

Google Earth uses pre World War II names for towns and villages in Vojvodina, Serbia.

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 [9].
• 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 [10].
• In 2006, one user spotted a large topographical replica in a remote region of China. The model is purportedly a small-scale version of the Karakoram Mountain Range, currently under the control of India. When later confirmed as a replica of this region, spectators began entertaining sinister military implications. [11] [12]
• Operators of the Lucas Heights nuclear reactor in Sydney, Australia asked Google to censor high resolution pictures of the facility [13]. However, they later withdrew the request [14].

Some citizens may express 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 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. [15] Capitol Hill used to also be pixelised in this way but this was lifted.

Whereas some critics have accused the software of revealing too much detail regarding properties, others have expressed concern over the willingness of Google to cripple their dataset to cater to special interests, believing that intentionally obscuring any land diminishes the accuracy of the application, and goes against its stated goal of letting the user "point and zoom to anyplace on the planet that you want to explore". [16]

Google Earth Community

The Google Earth Community is an online forum [17] 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 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. 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 [18]. 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

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 is capable of running additional add-on software such as movie making and advanced printing modules. [19]

References

1. ^ http://cyber.lamost.org/?p=23

See also

• List of Google services and tools
• Earth3D – [20]
• EarthSat
• Earthsim
• GEwar or Google Earth War
• WikiMapia
• Google Maps
• Google Moon and Google Mars
• Google Earth Community
• Google Earth Hacks
• NASA World Wind
• TerraServer-USA
• Pictometry
• ViewGL
• Virtual Earth
• Yinchuan - subject to an Internet phenomenon originating on Google Earth forum.

External links

• Official Google Earth Website - Download software from here

Community and placemarks

• Google Earth Community - German Google Earth-Community - A place for sharing placemarks
• Google Earth Community - A place for sharing placemarks
• Google Sightseeing Showcase site of interesting views
• EarthSpots Directory Of Interesting Places with links to open in Google Earth.
• AliensviewDatabase for GoogleEarth placemarks
• Thai placemarks on Earth
• ThaiEarth.com: Thai Google Earth User Community
• German Google Earth Placemarks Directory - More than 4 Million worldwide placemarks
• German Google Earth Community
• German Google Earth Community
• German location searchengine
• Over 100 file KMZ or FLY TO for Google Earth with preview.
• Geonames in GoogleEarth Over 142,000 cities from www.geonames.org (with geotags for wikipedia)
• earthplacemarks.com - A large collection of placemarks for Google Earth
• UK Secret Bases - revealed using Google Earth and many other online tools
• Topographic Map Archive - A growing collection of historic map overlays for Google Earth
• eemap.org - Chinese Google Maps mashup that allow people to share maps.
• Sakura mapping - Real Cherry blossoms mapping in Japan and worldwide.

Unofficial guides and tips

• Google Earth Blog - Featuring Google Earth news, features, tips, and technology
• Ogle Earth - A blog about Google Earth
• Google's Earth - Covering Google's Earth technology
• How Google Earth Works
• GISuser offers numerous Google Earth articles, tools, and news items
• Offers solutions for businesses to visualize their ecosystem using Google Earth
• Google Earth - The Guide of the Traveller

Add-ons

• View the T+L 500 on Google Earth - Travel + Leisure magazine's 500 Best Hotels
• Meet Other People All Around The World
• Google Earth Hacks Many placemarks, image overlays, etc.
• A file with coordinates from more than 48000 Wikipedia articles.
• LiveLookup find accommodation in Norway from within Google Earth, shows distance and direction relative to screen center. Live data is provided by: Reiselivsbasen
• Panoramio Community of geolocated photos of the World
• Gisuser's Google Earth/Maps tools Free Google Earth and Google Map add ons from GISuser
• Google Earth Connectivity Add-on for ArchiCAD 9
• Adventure Company find Adventure Holidays using Google Earth
• ViewGL Premium Aerial Photography Content for Google Earth
• Chicago Real Estate View 100,000+ Chicagoland properties

Games

• Play Google Earth - searching game Race to find a spot on Google Earth
• World Earth And Community Games A collection of both Google Earth games and Mass Multiplayer online games.
• Google Earth Game An online game via armchair travel
• adidas +10 Playoffs Flash game that plays within Google Earth's embedded web browser
• GEwar: Stragetic, Visual, financial and very popular wargame/community using Google Earth
• Global Earth Games A collection of games utilizing the Network Link system.
• Traceroute on Earth
• Hunter A mixed-reality treasure hunt involving Google Earth
• Global Hide and Seek - Global Hide and Seek, a simple blog based game of hide and seek using Google Earth imagery.
• Google Earth Fun - Google Earth Game, Aircraft in Flight, Corn Mazes and more.

Tools

• 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
• garmin2google A script to convert Garmin XML to Google Earth KML
• Control Google Earth via a webcam and lightbulbs held in your hand, see movie and link.
• KaMeLwriter Use hierarchical maps (Mind maps) to create and manage KML files and link in Excel data.
• Smustard 3D Text Tool A Google SketchUp 3D Signage tool for Google Earth.

Reviews

• Comparison with NASA World Wind

Other

• Google Earth: the black helicopters have landed
• Flash Earth - A flash based Google earth rendering, specifically for slower PCs and non Windows 2000/XP OS
• Virtual Globes Directory - worthwhile links to virtual globes
• Satellite snaps topless sunbathers