GPS Navigation systems

GPS Location systems

­GPS positioning systems

The Global Positioning System (GPS) is one of the navigation satellite systems which cover near to entire globe (except for polar regions). It has been developed for the needs of the U.S. Department of Defence for military purposes. However, it finally became available for civil purposes. Everyone can use it - all you need is a suitable GPS receiver.

The system is free to use and is not subject to restrictions. The technology has been widely employed in navigation and positioning systems both on land, at sea and in the air. The system consists of three segments:

  • space segment - 31 satellites orbiting the Earth at the medium earth orbit, located so that there are at least 4 of them within line of sight from everywhere on the globe. Each satellite sends a unique signal about the satellite constellation (the so called almanac) and information about their theoretical flight paths and deviations (known as ephemeris) as well as very precise time signal (atomic clock),
  • control segment – control stations which monitor and adjust the system operation,
  • user segment – receiving signals from the satellites.

How does GPS system work?

The purpose of the system is to deliver information about the user’s geographical position and height above sea level. This information can be used for location and navigation over the terrain. The system, to put it briefly, measures time at which signals from each satellite reach the receiver. Knowing the speed of the electromagnetic wave and the exact time of signal transmission the receiver calculates the distance from each satellite from which it has received the signal and, this way, determining the position of the receiver. To be able to determine the latitude and longitude it is necessary to receive signal from three satellites. To determine the distance, the fourth signal if required.

The system is highly precise – a standard access to the civil-use systems provides an accuracy of a few meters. However, you should also be aware of the system limitations. The main limitation is the need of the receiving antenna to ‘see’ the sky. This makes it impossible to use the system indoors and also on extremely cloudy days, when the positioning may be less accurate. The GPS technology is commonly knowns through navigation systems which greatly facilitate travelling and are popularly referred to as GPS. The system also provides huge possibilities in the field of monitoring of vehicles, boats, construction machinery and people. A GPS locator is a perfect solution for monitoring company vehicles or tracking someone’s car. GPS monitoring is also an excellent protection against theft of cars, valuable loads or expensive extremal facilities (e.g. LED advertising boards) - thanks to the motion alarm it is possible to take appropriate steps immediately. The GPS positioning system is also used to help protecting people – both children and elderly people. It is also used by mountain and water rescue teams. GPS data allow to determine the exact position and send this information as an SMS message via the cellular network or as a message to the server via GPRS packet transmission. For that purpose the locator has a built-in GSM module the same as in mobile phones. The module uses a standard SIM card (no SimLock in the device makes it compatible with cards of any operator).

The locators that we offer in our store enable real-time position tracking via the GPS website. Information is displayed on a map. It shows the speed of the tracked object and provides a number of additional features e.g. alerts (on position change, on standstill for a specified time and many other). What’s important, is that the use of this system is free of chargé and no subscription fee is required. The only costs the user is to bear are: the cost of the SIM card in the locator and the cost of SMS commands sent to the device in order to change its parameters.

How to choose GPS tracker?

The key aspect when choosing the tracking device is the purpose it is supposed to serve. The user needs to specify where and for what purpose the locator is going to be placed and how long it is supposed to work without recharging or changing batteries. It might be that possibility of connecting the device to the power supply or other car systems is essential.

GPS locators for different applications