History & Geography of Google Earth

In June 2005, Google launched its Google Earth tool, powered by Keyhole Technology from Keyhole, a company that Google acquired last year. Google Earth is a standalone application that's essentially an enhanced and upgraded version of its Keyhole 3D satellite imagery product. The underlying Keyhole technology includes tens of terabytes of aerial images spanning the globe.

Currently, Google Earth has only medium resolution images for most parts of the world। For about 38 US cities, Google Earth has high-resolution images that permit 3-D ‘walkthrough’ capability. Information can be overlaid over ‘layers’ so that themes (hospitals, hot-spots, restaurants and libraries) can be separated into layers and super-imposed only when needed.

DEVELOPMENT

Google has launched an impressive number of geospatial applications since the purchase of Keyhole. Google Earth utilizes broadband streaming technology and 3D graphics on web, much like a videogame, enabling users to interactively explore the world. Important timelines are as:

Google Local – March 2004 beta site released

Keyhole Acquisition – October 28, 2004

Google Maps – February 2005

Google Maps Imagery Layer – April 2005

Mobile Google Local – April 13, 2005

Google Earth – June 27, 2005

PRODUCTS: Google Earth is free for all Google users. There is also a Google Earth Plus that allows GPS devices to be connected and Google Earth Pro for businesses. One of the key features of Google Earth Pro is its GIS import capabilities.
OTHER SIMILAR PRODUCTS: MSN Virtual Earth, MapQuest, NASA WorldWind, Wikimapia, ESRI ArcGIS Explorer

FEATURES

Key features of Google Earth include:
3D buildings in major cities across the United States
3D terrain showing mountains, valleys, and canyons around the world
Integrated Google Local search to find local information such as hotels, restaurants, schools, parks, and transportation
Video playback of driving directions
Tilt, rotate, and activate 3D terrain and buildings for a different perspective on a location
Easy creation and sharing of annotations among users

APPLICATIONS

The application is a "console" with controls allowing you manipulate 3D satellite imagery of the Earth in a viewer directly above the controls. Google Earth has three primary search features: Fly To, Local Search and Directions। People are making their own maps, like the OpenStreetMap project, and "mashups" have been born - where maps are customised with data for practical and frivolous purposes.

Accuracy: good if you do not zoom-in too much। Remember the old axiom that says all maps lie because all maps lie flat.