How GPS and Satellite Work

GPS is a system used to determine the position on the earth's surface with the help of satellite signals. The easy process is to send a signal from the space station and the signal is captured by the earth station. History records that GPS was first developed by the United States Department of Defense, namely NAVSTAR GPS.

GPS and Stellite Work

Reff : www.wikipedia.com

Satellite systems use a number of satellites that are in the Earth's orbit by emitting signals and captured by receivers on the earth station. The parts that play a role in this transmission system are:

• Control Section,

Has a role to control the signal to be sent to the receiver. Each satellite can be located just outside the orbit which is useful for tracking satellite orbit, altitude, and satellite speed. The signals sent by the satellite are received by the control section to be corrected and sent back to the satellite. The results of this correction data are called "emphemeris" data which will be sent to the user's navigation device.

• Space Division

This section consists of various types of satellites in Earth orbit. Data collected by the satellite is a "Pseudo-Random" signal with a different code for each satellite. The wave used for navigation is L1 at a frequency of 1575.42 MHz (a signal commonly used for navigation for the general public) and L2 with a frequency of 1227.6 MHz (which is normal used for military purposes)

• User Section

The satellite will transmit data that will be received by the navigation device regularly and continuously. Ephemeris data is transmitted by satellite, and has a validity of about 4-6 hours. To determine the coordinates of a navigation device, at least 3 signals from the satellite are needed. From the satellite signals it will be processed by the navigation tool to be processed with certain calculations and issue the results of coordinate points. The accuracy of the calculation of navigation tools is affected by the number of signals received by satellites in the Earth's orbit.