Google Maps

Google Maps
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Screenshot of Google Maps showing a route from Toronto to Ottawa on the 400-Series highways.
Screenshot of Google Maps showing a route from Toronto to Ottawa on the 400-Series highways.
Penang island and Seberang Prai on the mainland as seen on Google Maps
Penang island and Seberang Prai on the mainland as seen on Google Maps [1]

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 the Google Maps website, 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 numerous countries around the world.

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

* 1 Features
* 2 Satellite view
* 3 Implementation
* 4 Extensibility and customization
o 4.1 Google Maps API
* 5 Development
* 6 Coverage details
* 7 Google's use of Google Maps
o 7.1 Google Bendi (谷歌本地) and Google Ditu (谷歌地图)
o 7.2 Google Mars
o 7.3 Google Moon
o 7.4 Google Ride Finder
o 7.5 Google Transit
* 8 Copyright
* 9 Criticism
* 10 Popular culture
* 11 See also
o 11.1 Comparable services
* 12 References
* 13 External links
o 13.1 Google Maps discussion websites
o 13.2 Examples of web tools employing Google Maps
o 13.3 Websites collecting Google Maps aerial views

[edit] Features

Google Maps features a map that can be navigated by dragging the mouse, or using the mouse wheel to zoom in (mouse wheel up) or out (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 and 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.

[edit] Satellite view
Screenshot of Google Maps (satellite) showing Monster Park in San Francisco, CA
Screenshot of Google Maps (satellite) showing Monster Park in San Francisco, CA

Google Maps provides high-resolution 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, Egypt, France, Iran, 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 most of 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 Virtual 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.

Although Google uses the word "satellite", some of the high-resolution imagery is aerial photography rather than satellite imagery.

[edit] 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,[2] 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 provides the essential foundation for the entire application.

The underlying technology used in both Google and Yahoo! maps is available from deCarta (formerly Telcontar)[3].

[edit] Extensibility and customization
Chicagocrime.org, developed by Adrian Holovaty, was among the first and most popular Google Maps mashups.
Chicagocrime.org, developed by Adrian Holovaty, was among the first and most popular [4] Google Maps mashups.

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 [5], student apartment rentals [6] [7], and local map Chicago crime data [8] (or check Misdaadkaart.nl showing crimes of one entire country[9]). 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.

[edit] 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 [10] 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 [11], 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 [12] . Both were released to coincide with the O'Reilly Web 2.0 Conference. Yahoo! Maps lacks international support, but included a geocoder in the first release.

As of October 2006, Google Gadgets' Google maps implementation is much easier to use with just the need of one line of script. The drawback is that it is not as customizable as the full API.

In late 2006, Yahoo began a campaign to upgrade their maps, to compete better with Google Local and other online map companies. Several of the maps used in the survey were similar to Google maps. The online survey is here.

[edit] 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. (Google has reverted to pre-Katrina imagery without explanation)
* 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 [13] 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.
* Beginning in February 2007, buildings and subway stops are displayed in Google Maps "map view" for New York City, Washington, D.C., London, San Francisco, and some other cities.[14]

[edit] Coverage details

The specific features of Google Maps available depend on the location of the world.[15]

Maps, local business search, street-level search, and driving directions are fully functional for

* Australia
* Canada
* China (beta via ditu.google.com)
* France
* Germany
* Italy
* Netherlands
* Spain
* United Kingdom (local search only functional via maps.google.co.uk)
* United States

Maps, local business search, and street-level search are fully functional for

* Japan

Google Local Business Center for business owners to add listings to Google Maps is available in

* Canada
* China
* Japan
* France
* Germany
* Italy
* Spain
* United Kingdom
* United States



Maps only are fully functional for

* African continent (street coverage – select major cities only)
* Andorra
* Austria
* Belgium
* Brazil
* Czech Republic
* Denmark
* Eastern Europe/former Soviet Union states (highway coverage only)
* Finland
* Gibraltar
* Greece
* Hong Kong
* Hungary
* India (street coverage for most cities, highway coverage for whole country)
* Ireland
* Liechtenstein
* Luxembourg
* Monaco
* New Zealand
* Norway
* Poland
* Portugal
* Russia (street coverage – Moscow & St. Petersburg only)
* San Marino
* Singapore
* Slovakia
* Sweden
* Switzerland
* Turkey (street coverage – Istanbul, Ankara, and Bursa only)

Satellite imagery of varying resolution is available worldwide.