Google Maps (for a time named Google Local) is a free web mapping service 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 for bicycles, pedestrians (routes less than 6.2 miles) and cars, and an urban business locator for numerous countries around the world.
A related product is Google Earth, a stand-alone program for Microsoft Windows, Mac OS X, and Linux which offers more globe-viewing features.
Satellite view
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 New Zealand, Australia, Egypt, France, Germany, Greece, Hong Kong, Hungary, Iran, Iceland, Italy, Ireland, Iraq, Japan, Jordan, Taiwan, the Bahamas, Bermuda, Kuwait, Mexico, the Netherlands, the United Kingdom, and many other countries. Google Maps also covers many cities including Moscow, Istanbul, and most of India.
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 New Zealand, Australia, Egypt, France, Germany, Greece, Hong Kong, Hungary, Iran, Iceland, Italy, Ireland, Iraq, Japan, Jordan, Taiwan, the Bahamas, Bermuda, Kuwait, Mexico, the Netherlands, the United Kingdom, and many other countries. Google Maps also covers many cities including Moscow, Istanbul, and most of India.
Various governments have complained about the potential for terrorists to use the satellite images in planning attacks. 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 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 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 stadia and unique earth formations.
Although Google uses the word "satellite", most of the high-resolution imagery is aerial photography taken from airplanes rather than from satellites
Like many other Google web applications, Google Maps uses JavaScript extensively. As the user drags the map, the grid squares are downloaded from the server and inserted into the page. When a user searches for a business, the results are downloaded in the background for insertion into the side panel and map - the page is not reloaded. Locations are drawn dynamically by positioning a red pin (composed of several partially-transparent PNGs) on top of the map images.
The technique of providing greater user-interactivity by performing asynchronous network requests with Javascript and XMLHttpRequest has recently become known as Ajax. Maps actually uses XmlHttpRequest sparingly, preferring a hidden IFrame with form submission because it preserves browser history. It also uses JSON for data transfer rather than XML, for performance reasons. These techniques both fall under the broad Ajax umbrella.
The GIS (Geographic Information System) data used in Google Maps are provided by Tele Atlas, NAVTEQ, MapABC],
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). Landsat 7's maximum ground imagery was 15 m (49 ft) for black and white.
QuickBird's designed maximum ground imagery is 60 cm (24 in). This global image base provides the essential foundation for the entire application.
On September 6, 2008, a Delta II rocket bearing the Google logo lifted off from Vandenberg Air Force Base. It carried the GeoEye-1 satellite, the most powerful commercial space image satellite yet launched. The satellite will provide 41-centimeter (16-inch) imagery to the United States government, and downsampled 50-centimeter (20-inch) imagery to Google, which has the exclusive rights to use the images for mapping. Press releases said Google's imagery will be able to display home plate in baseball parks. GeoEye's IKONOS satellite (which has a maximum ground resolution of 82 cm (32 in)) provides images to Microsoft and Yahoo
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 customised 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 metadat, and even custom map image sources into the Google Maps interface. The script-insertion tool Greasemonkey provides a large number of client-side scripts to customize Google Maps data.
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
Google created the Google Maps API to facilitate developers integrating Google Maps into their web sites with their own data points. It is a free service, which currently does not contain ads, but Google states in their terms of use that they reserve the right to display ads in the future.
By using the Google Maps API it is possible to embed the full Google Maps on an external web site. Developers are required to request an API Key, which is bound to the web site and directory entered 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. 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 a survey were similar to Google maps.
Google Maps actively promotes the commercial use of their API. One of its earliest adopters at large scale are real estate mashup sites. Google's case study is about Nestoria, a property search engine in the UK and Spain.
Google Ride Finder
Google launched an experimental Google Maps-based tool called Ride Finder, 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 U.S. cities, including Chicago and San Francisco on a Google Maps street map.
Google Transit
In December 2005, Google launched Google Transit. This is a web application (listed in Google Labs), that plans a trip using public transportation options. Google Transit launched with support for Portland, Oregon. Information for Eugene, Oregon; Honolulu, Hawaii; Pittsburgh, Pennsylvania; Seattle, Washington; and Tampa, Florida was added on September 27, 2006, with more added since including adding cities in Canada, Europe, Japan and Perth. The service calculates route, transit time and cost, and can compare the trip to one using a car.
Google My Maps
In April 2007, My Maps was a new feature added to Google's local search maps. My Maps lets users and businesses create their own map by positioning markers, polylines and polygons onto a map. The interface is a straightforward overlay on the map. A set of eighty-four pre-designed markers is available, ranging from bars and restaurants to webcam and earthquake symbols.
Polyline and Polygon colour, width and opacity are selectable. Maps modified using My Maps can be saved for later viewing and made public (or marked as private), but cannot be printed. Note: this can easily be overcome by using the 'Print Screen' funtion key and simple image editing software such as Paint.
Each element added to a My Map has an editable tag. This tag can contain text, rich text or HTML. Embeddable video and other content can be included within the HTML tag.
Upon the launch of My Maps there was no facility to embed the created maps into a webpage or blog. A few independent websites have now produced tools to let users embed maps and add further functionality to their maps. This has been resolved with version 2.78.
Google Street View
On May 25, 2007, Google released Street View, a new feature of Google Maps which provides 360° panoramic street-level views of various U.S. cities. On this date, the feature only included five cities, but has since expanded to fifty-seven, with plans for more U.S. and Canadian cities in the future. Some cities, like San Francisco, are in high resolution, while other cities are limited in resolution.
In August 2008, Australia was added to the Street View feature with nearly all Australian highways, roads and streets having the feature. Australia is the country to date with the most coverage for Google street view. In addition in that month Japan was added and the Tour de France route was added on July 2 of that year.
Google Street View has also gained a significant amount of controversy in the days following its release; privacy concerns have erupted due to the uncensored nature of its panoramic photographs
