google maps

Google Maps (for a time named Google Local) is a free web map server application and technology provided by Google that powers many map-based services including Google Maps, Google Ride Finder and embedded maps on third-party websites via the Google Maps API. It offers street maps, a route planner and an urban business locator for Australia, Canada, Japan, New Zealand, the United States, most western European countries, the city of Moscow, the Canary Islands, and Brazil, and satellite images for the whole world.

A related product is Google Earth, a standalone Apple Mac, Windows and Linux program that offers enhanced globe-viewing features.

Features

Google Maps features a map that can be navigated by dragging the mouse, or zoomed in (scrolling the mouse wheel up) and out (scrolling the mouse wheel down) to show detailed street information. The user can also control the map with the arrow keys to move to the desired location. To allow for quick movement, the "+" and "-" keys can be used to control the zoom level. Users may enter an address, intersection or general area to quickly find it on the map.

Search results can be restricted to a certain area, thanks to Google Local. For example, someone can enter a query such as "Waffles in Ottawa"[1] to find restaurants serving waffles near the city. This can be used to find a wide variety of businesses, such as theatres, restaurants or hotels.

Like many other map services, Google Maps allows for the creation of driving directions. It gives the user a step-by-step list of how to get to their destination, along with an estimate of the time required to reach it and the distance between the two locations.

Google Maps offers three viewing modes by default: Map (Street map views), Satellite (satellite and high-resolution aerial photographs) and Hybrid (Street maps overlaid on satellite and high-resolution aerial photographs).

The "link to this page" link on each Google Maps map targets a URL which can be used to find the location on the map at a later time. The latitude and longitude can be used as input to NASA World Wind or TerraServer-USA, which in some cases have higher-resolution imagery.

Satellite view

Google Maps provides high-resolution (full-zoom) satellite images for most urban areas in Canada and the United States (including Hawaii, Alaska, Puerto Rico, and the U.S. Virgin Islands) as well as parts of Australia, France, Iceland, Italy, Iraq, Japan, the Bahamas, Bermuda, Kuwait, Mexico, the Netherlands, the United Kingdom and many other countries. Google Maps also covers the cities of Moscow, Istanbul, and also Bangalore, Chennai, Salem, Mumbai and New Delhi in India.

All the images shown in Google Maps' satellite mode are at least a year old and in some places up to five years old. Despite this various governments have complained over the potential for terrorists to use the satellite images in planning attacks on nuclear power stations. Google has blurred some areas for security (mostly in the United States), including the U.S. Naval Observatory area (where the official residence of the Vice President is located, and until recently, the United States Capitol and the White House (which formerly featured erased housetop). Other well-known government installations are visible including the infamous Area 51 in the Nevada desert.

With the introduction of an easily pannable and searchable mapping and satellite imagery tool, Google's mapping engine prompted a surge of interest in satellite imagery. Sites such as Google Sightseeing and Google Globetrotting were established which feature satellite images of interesting natural and man-made landmarks, including such novelties as "large type" writing visible in the imagery, as well as famous stadiums and unique earth formations.

Implementation

Like other Google web applications, a large amount of JavaScript was used to create Google Maps. As the user drags the map, the grid squares are downloaded from the server and displayed to the user. When a user searches for a business, the location is pin-pointed with a red pin, which is actually a transparent PNG placed over the map. The technique of providing greater user-interactivity by performing asynchronous network requests with Javascript and XML has recently become known as Ajax. Specifically, Google Maps was built using the AjaXSLT framework.

The GIS (map) data used in Google Maps are provided by Tele Atlas and NAVTEQ, while the small patches of high-resolution satellite imagery are largely provided by DigitalGlobe and its QuickBird satellite, with some imagery also from government sources. The main global imagery base called NaturalVue was derived from Landsat 7 imagery by MDA Federal (formerly Earth Satellite Corporation). This global image base provide the essential foundation for the entire application.

The underlying technology used in both Google and Yahoo! maps is available from deCarta (formerly Telcontar)^[2].

Extensibility and customization

As the Google Maps code is almost entirely JavaScript and XML, some end-users reverse-engineered the tool and produced client-side scripts and server-side hooks which allowed a user or website to introduce expanded or customized features into the Google Maps interface.

Using the core engine and the map/satellite images hosted by Google, such tools can introduce custom location icons, location coordinates and metadata, and even custom map image sources into the Google Maps interface. Some of the more well-known of these "Google Maps Hacks" include tools that display locations of Craigslist rental properties ^[4], student apartment rentals ^[5], and local map Chicago crime data ^[6] (or check Misdaadkaart.nl showing crimes of one entire country^[7]). The script-insertion tool Greasemonkey provides a large number of client-side scripts to customize Google Maps data, and the mygmaps.com website provides an interface for easily adding your own set of locations and viewing them on Google Maps.

Combined with photo sharing websites such as Flickr, a phenomenon called "memory maps" emerged. Using copies of the Keyhole satellite photos of their home towns or other favorite places, the users take advantage of image annotation features to provide personal histories and information regarding particular points of the area.

Google Maps API

The Google Maps API was created by Google to facilitate developers integrating Google Maps into their web sites, with their own data points. It is a free service, that currently does not contain ads, but Google states in their terms of use ^[8] that they reserve the right to display ads in the future.

By using the Google Maps API you can embed the full Google Maps on an external web site (minus driving directions and KML). Start by creating an API Key ^[9], it will be bound to the web site and directory you enter when creating the key. Creating your own map interface involves adding the Google JavaScript code to your page, and then using Javascript functions to add points to the map.

When the API first launched it lacked the ability to geocode addresses, requiring you to manually add points in (latitude, longitude) format. This has since been rectified.

At the same time as the release of the Google Maps API, Yahoo! released their own Maps API ^[10] . Both were released to coincide with the O'Reilly Web 2.0 Conference. Yahoo! Maps lacks international support and aerial photos, but included a geocoder in the first release.

Development

Google Maps was first announced on the Google Blog on February 8, 2005 and was located at http://maps.google.com/. It originally only supported users of Internet Explorer and Mozilla web browsers, but support for Opera and Safari was added on February 25, 2005. Currently (July 1, 2006) Internet Explorer 6.0+, Firefox 0.8+, Safari 1.2.4+, Netscape 7.1+, Mozilla 1.4+, and Opera 8.02+ are supported (see Google Maps Help). It was in beta for 6 months before becoming part of Google Local on October 6, 2005.

• In early April 2005, an alternate view was activated to show Satellite images of the area displayed.
• In late April 2005, Google created Google Ride Finder using Google Maps.
• In late June 2005, Google released the Extensibility and customization.
• In mid July 2005, Google began Google Maps and Google Local services for Japan, including road maps.
• On July 22, 2005, Google released "Hybrid View". Together with this change, the satellite image data was converted from plate carrée to Mercator projection, which makes for a less distorted image in the temperate climes latitudes.
• In July 2005, in honor of the thirty-sixth anniversary of the Apollo Moon landing, Google Moon was launched.
• In September 2005, in the aftermath of Hurricane Katrina, Google Maps quickly updated its satellite imagery of New Orleans to allow users to view the extent of the flooding in various parts of that city.
• As of January 2, 2006, Google Maps features road maps for the United States, Puerto Rico, Canada, Great Britain, Japan, and certain cities in Northern Ireland and the Republic of Ireland. Coverage of the area around Turin was added in time for the 2006 Winter Olympics.
• On January 23, 2006, Google Maps was updated to use the same satellite image database as Google Earth.
• On March 12, 2006, Google Mars ^[11] was launched, which features a draggable map and satellite imagery of the planet Mars.
• In late April 2006, Google Local was merged into the main Google Maps site.
• On April 3, 2006, version 2 of the Maps API was released.
• On June 11, 2006, Google added geocoding capabilities to the API, satisfying what it called the most requested feature for this service.
• On June 14, 2006, Google Maps for Enterprise was officially launched. As a commercial service, it features intranet and advertisement-free implementations.

Google's use of Google Maps

The main Google Maps site includes a local search feature, finding businesses of a certain category in a geographic area.

Google Mars

Google Mars provides a visible imagery view, like Google Moon, as well as infrared imagery and shaded relief (elevation). Users can toggle between the elevation, visible, and infrared data, in the same manner as switching between map, satellite, and hybrid modes of Google Maps. In collaboration with NASA scientists at Arizona State University, Google has provided the public with data collected from two NASA Mars missions, Mars Global Surveyor and 2001 Mars Odyssey^[12]. At present, you cannot use the Google Earth desktop client to access the data, but the feature is in development.

It is currently not known whether or not Google Mars will become a stand-alone program and if said program will include shots of the highly popular martian face or the martian pyramids.

Google Moon

In honor of the 36th anniversary of the Apollo 11 moon landing (July 20, 2005), Google took public domain imagery from NASA of the Moon, and integrated it into the Google Maps interface. By default this tool, with a reduced set of features, also displays the points of landing of all Apollo spacecraft to land on the Moon. This tool also includs an easter egg, displaying a Swiss cheese design at the highest zoom level. Google Moon, as it is called, was linked from a special commemorative version of the Google logo displayed at the top of the main Google search page for the duration of July 20 (UTC).

Google Ride Finder

Google launched an experimental Google Maps-based tool called Ride Finder[2], tapping into in-car GPS units for a selection of participating taxi and limousine services. The tool displays the current location of all supported vehicles of the participating services in major cities, including Chicago and San Francisco on a Google Maps street map.

Google Transit

In December 2005, Google launched Google Transit[3]. This is a beta web application (listed in Google Labs), that plans a trip using public transportation options. It is currently available for Portland, Oregon, Eugene, Oregon, Honolulu, Hawaii, Pittsburgh, Pennsylvania, Seattle, Washington, and Tampa, Florida in the USA. The service calculates route, transit time and cost, and can compare the trip to one using a car.

Copyright

Google Maps Terms and Conditions[4] state that usage of material from Google Maps is regulated by Google Terms of Service[5] and some aditional restrictions. Terms and Conditions, among other, state:

For individual users, Google Maps [...] is made available for your personal, non-commercial use only. For business users, Google Maps is made available for your internal use only and may not be commercially redistributed [...][6]

Criticism

Street map overlays, in some areas, may not match up precisely with the corresponding satellite images. The street data may be entirely erroneous, or simply out of date. Google Earth representative Brian McLendon explained :

"The biggest challenge is the currency of data, the authenticy of data," .... In other words: The main complaints the Google guys get are "that's not my house" and "that's not my car." Google maps satellite images are not in real time; they are several years old. [7]

Google maps has gained most acclaim by web developers. GIS professionals however, tend to regard Google maps as a rather simplistic viewing tool compared to the features offered by standalone GIS applications.

There is also some disappointment among developers that the potential of Google's geocoding technology is limited by legal restrictions in some countries for web application development, notably the UK, where postcodes cannot be easily translated into latitudes and longitudes like Zip codes in the US. This is due to the crown copyright over this geographical data. Some sites have managed to circumvent this problem by purchasing their own postcode data and combining this with Google Maps. The usage of Google Maps on a large scale outside the US remains limited.

See also

• WikiMapia a project aimed at "describing the whole planet earth". It is an Internet resource combining Google Maps and a "wiki" system.
• List of Google services and tools
• NASA World Wind
• TerraServer-USA
• Google Earth
• Google Sightseeing
• Virtual Earth
• Placeopedia
• Mobile GMaps
• Pintomap

Comparable services

• A9 Maps (This rival from Amazon.com offers detailed street level pictures taken from a van-mounted camera - for 24 US-cities only)
• Ask.com Maps & Directions
• Géoportail (A french rival offering detailed satellite pictures of french territories)
• map.search.ch (Switzerland, the first Ajax map)
• Map24
• MapQuest
• Multimap.com
• Routenplaner24 (German)
• Terralink International
• Windows Live Local (Microsoft's answer to Google Maps, with road maps, aerial/satellite imagery, and street-level photos via the Windows Live Local Preview.)
  • TerraServer-USA (Public domain satellite imagery via Microsoft servers)
  • Virtual Earth (The original Microsoft service that powers the current Windows Live Local)
• Yahoo! Maps

References

1. ^ http://maps.google.com/maps?q=Georgetown,+Malaysia&spn=0.312132,0.515654&t=k&hl=en
2. ^ http://www.decarta.com/
3. ^ http://abcnews.go.com/Technology/wireStory?id=832264
4. ^ http://www.housingmaps.com/
5. ^ http://www.gooffcampus.com/
6. ^ http://www.chicagocrime.org/
7. ^ http://www.misdaadkaart.nl/
8. ^ Google Maps API - Terms of use.
9. ^ Google Maps API key.
10. ^ Yahoo! Maps API.
11. ^ http://mars.google.com/
12. ^ http://www.google.com/mars/about.html

External links

• Google Maps

• Mobile phone version

• Google Moon
• Google Earth
• Google Mars
• Google Maps API

Google Maps discussion websites

• Google Maps Mania, a blog tracking the websites, ideas and tools being influenced by Google Maps
• Google Maps Google group
• Google Maps API Google group

Examples of web tools employing Google Maps

• Incidentlog.com, real-time and historic archive of police, fire, and 911 incidents for many major U.S. cities.
• Cell Phone Reception and Tower Search, graphical cell phone reception and tower locator compiled from the FCC's antenna registration database (US Only).
• Google Maps Route Planner, clickable arbitrary-point driving direction generator.

Websites collecting Google Maps aerial views

• List of images compiled by Wikipedia users
• Google Sightseeing Showcase site of interesting views
• Virtual Globetrotting Archival site of interesting views
• Sightseeing with Google Satellite Maps Over 8000 US and international sites