Google Earth

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Google Earth (from Earth - the planet) - the project of Google company within which into Internet network the satellite photos of all terrestrial surface have been placed. Permission of photos of some regions is unprecedented.

Unlike other similar services showing satellite pictures in a usual browser (for example, Google Maps or TerraServer), the special client program Google Earth, loaded onto a computer of the user is used in the given service. Such approach though demands the consumption of the superfluous traffic necessary for downloading the program, but in the further provides additional opportunities, inconceivable for usual web-interface.

This program has initially been released by Keyhole company, and then bought by Google company which has made the program popular.

Opportunities of the program:

- Google Earth automatically pumps up from the Internet the images necessary for the user and other data, keeps them in operative memory of a computer and on a hard disk for further use. Downloaded data are kept on a disk, and at the subsequent starts of the program only new data are downloaded that allows to save the traffic essentially.

- For visualization of the image the three-dimensional model of all globe is used (in view of height above sea level) which is displayed on the screen by means of interfaces DirectX or OpenGL. In three-dimensionality of landscapes of the Earth surface the main difference of Google Earth program from its predecessor Google_Maps also consists. The user can easily move to any point of a planet, operating by position of the virtual camera.

- Practically all land surface is covered by the images received from DigitalGlobe company and having the 15 meters permission per pixel. There are separate sites of a surface (as a rule, covering capitals and some large cities of the majority of the world countries), having more higher permission. For example, Moscow is photographed with the permission of 0,6 meters per pixel, and many cities of USA with the permission of 0,15 meters per pixel. Data of a landscape have the permission of the order of 100 meters.

- Also there is a huge quantity of additional data which can be connected at will of the user. For example, names of settlements, reservoirs, airports, roads and the other information. Besides for cities of USA there is more detailed information - names of streets, shops, refuellings, hotels, etc.

- Users can create own labels and impose the images atop of satellite images (it can be maps, or more detailed photos received from other sources). It is possible to exchange by these labels with other users of the program through the Forum http://bbs.keyhole.com/. The labels sent onto this forum approximately in a month become visible to all users of Google Earth.

- There is a function of measurement of distances.