GPS Segment

8 Pages 1999 Words

on 2.1, 2.2, and 2.3 respectively.


2.1 User Segment

Anyone who uses GPS and the receivers they use make up the user segment of GPS. GPS has a very wide range of users. The list of users runs from the United States military to professional users, such as land surveyors, all the way to recreational users. Although originally intended for military use the number of civilian users far out numbers the military users. Each different user has different needs when it comes to uses and accuracy. A land surveyor for instance may need sub-centimetre level measurements while a recreational boater would only need positions accurate two under 20 metres to find out the best possible route to a previous marked good fishing area. Although each user has various uses for GPS the receiver is the basic element of the user segment and they all work on similar principles. This chapter contains a basic run though about how a GPS works.
A GPS receiver is very complex and its operation and how it works is far from simple but is basically works as follows. A GPS receiver obtains signals sent from a system of satellites, which orbit around the earth (the space segment) to triangulate a position on earth. A GPS receiver determines the distance from satellites, known distances away, by calculating the time it takes a signal sent from the satellite to the receiver.
Although this sounds simple enough GPS uses some of today’s most complicated technology. Assuming that the satellites position in space is known then the distance from one satellite limits the rece...