What is GPS?

Answer 1

My guess would be "gass permeable" but of course it depends on the context...

Answer 2

GPS stands for Global Positioning System and is a satellite-based radio navigation system. While common use of the term GPS began relatively recently, the system dates back to the 1960s when it was first developed and operated by the U.S. Department of Defense (DOD).

In 1966, a Presidential Decision Directive was issued and later passed into law that transferred the "ownership" of the system to an Interagency GPS Executive Board (IGEB), with representatives from DOD, the U.S. Department of Transportation and other government agencies. This transfer was done primarily to make sure GPS could be used effectively for both civil and military user needs.

GPS itself is made up of three component groups - the satellite constellation, ground control segment, and user equipment. The satellite constellation is often referred to as NAVSTAR (Navigation Satellite Timing and Ranging) and currently consists of 30 satellites. Groups of five satellites loop around the earth in one of six different orbital paths. This allows a system user with a clear view of the sky to have access to a minimum of four satellites at any one time, but more commonly six to eight.

The paths the satellites follow are the earth are circular and are about 60o apart. (To visualize these, imagine a pie cut into 6 pieces and then envision the pie being round instead of flat.) A satellite takes about 12 hours to complete one orbit or, in other words, will travel around the earth twice in one day.

The Ground Control Segment consists of the Master Control Station (MCS) and six monitoring stations. The MCS, based near Colorado Springs, Colorado, at on Schriever Air Force Base, controls and operates the system. The monitoring stations are located around the world at Ascension Island, Diego Garcia, Kwajalein , Hawaii , Cape Canaveral and Colorado Springs. These stations continuously track and collect data from the satellites and have two cesium clocks referenced to GPS system time to ensure consistency.

(Note: GPS system time is slightly ahead of Coordinated Universal Time (UTC), which is maintained by atomic clocks. The reason is that GPS does not make adjustments, like UTC does, to track with solar time. However, a GPS receiver does make a clock adjustment so the user is on UTC time.)

The third component of the GPS system is the user equipment, commonly called GPS receivers. These range from navigation systems found on planes and in cars to hand held devices now available. A receiver uses signals received from three or more satellites to determine the position of the user.

GPS, or Global Positioning System, is used to fix one's position on the Earth through the very accurate timing of signals from satellites. It's applications are many and varied, ranging from aircraft and ship navigation, to geocaching (treasure hunting) for individuals. There are also a multitude of military applications for GPS.

http://en.wikipedia.org/wiki/Global_Positioning_System

it is a service provided by a set of American satellites that allows a device in many locations on the world to determine it's latitude and longitude, usually with a maximal accuracy of ~10 meters, but can be more or less depending on weather, being indoors/outdoors (usually doesn't work indoors), or quality of device.
GPS, or Global Positioning System, is a system that allows for the localization of any place on Earth; navigation of boats or planes and more precise mapping. It can do so due to a network of 24 satellites (each one circles Earth in a period of 12 hours and transmits microwave signals in pre-determined intervals of 1ms). For the calculations, the triangulation technique is used, a method of determining the relative positions of objects using the geometry of triangles.