What are affordable options in GPS location

GPS - navigation by satellite

GPS - navigation by satellite
Image: gstockstudio-fotolia.com, graphics / assembly: teltarif.de Positioning and navigation by satellite has rapidly gained in importance in recent years. Navigation devices for the car are now affordable for everyone, and GPS has also become a standard feature on smartphones. GPS-based services on cell phones have become part of everyday life. Satellite-based location determination found its way into photography with "geotagging" and satellite-based helpers are usually included in outdoor sports, from bicycle tours to mountain hikes.

GPS (Global Positioning System) is the buzzword that is generally used for location determination and navigation with satellite support. In fact, it is the American global satellite navigation system that is used in various ways for positioning and navigation around the world. In the following you will find details about the historical and technical background of GPS, which GPS-based services you can use and which GPS competing systems are already available or are being set up.

GPS - worldwide satellite positioning and navigation

GPS satellite constellation (scheme)
Graphic: GPS The GPS developed by the American military - the full name is NAVSTAR-GPS (Navigational Satellite Timing and Ranging GPS) - is currently the most widely used system for satellite positioning with worldwide coverage. GPS has also been approved for civil use by the US government, but control remains with the US Department of Defense. In our detailed guide you will find everything you need to know about the historical development of GPS satellite technology.

The GPS satellite system consists of 30 satellites orbiting the earth at an altitude of around 20,000 kilometers and at 11,200 km / h in six orbits - including 21 satellites that are required for operation, three replacement satellites and six other reserve satellites. On earth, a main control station (secured by a second MCS, master control station), six monitor stations of the U.S. Air Force as well as 11 civil stations under official control the task of monitoring and correcting the satellite trajectories.

How does GPS position determination work?

GPS - navigation by satellite
Image: gstockstudio-fotolia.com, graphics / assembly: teltarif.de The actual GPS receivers have an omnidirectional antenna with which they receive the radio data from the satellites. The exact location of the receiver - for example a navigation system - is now determined from its distance to at least three satellites: For the calculation, the position data of the satellites and the transit time (i.e. the time difference between sending and receiving) of the radio signals are evaluated. To ensure the accuracy of the transit time calculation, another satellite is required as a reference for the time, because while the satellites are equipped with atomic clocks, GPS receivers work with quartz clocks - a small time deviation can lead to immense inaccuracies in the determination of the location. So at least four satellites must always be visible from Earth, but the following also applies: the more satellites that can be received at the same time, the more precise the position determination will be. GPS receivers used in the private sector now receive radio data from 12 satellites.

With these devices you can use GPS privately

In principle, GPS can be used worldwide and at any time free of charge. However, with the classic GPS receivers, costs for special maps may arise in addition to the purchase price. In addition to built-in and mobile navigation devices for the car, the robust outdoor handhelds from Garmin, Magellan, Falk and TomTom, for example, are now also available in cell phone size. And the reception devices continue to shrink: GPS watches for the wrist are offered for sports and outdoor use.

Smartwatches with GPS support

In addition, there are very small GPS trackers for quickly finding pets, objects such as bicycles, suitcases or cars and those with an SOS function for the quick care of people in need of help and care in an emergency. The devices usually have a SIM card for transmitting the data to a smartphone or via the Internet to a computer. GPS loggers, on the other hand, have an internal memory on which, for example, outdoor tours are recorded, which can later be read out on the PC. With a GPS mouse, a tablet, laptop, PC or smartphone can also be turned into an even more precise and powerful navigation device via cable or Bluetooth. The smartphone itself can also be transformed into a navigation system via an app - however, a mobile radio-supported assistance system, the Assisted Global Positioning System (A-GPS), is used, which means that provider and network-dependent fees are also due.

Smartphones with GPS support

GPS gets competition

The American monopoly on positioning and navigation by satellite and the associated dependencies are of course a thorn in the side of other governments. Therefore there are now some alternatives to GPS. Russia developed its GLONASS system as early as the Cold War, which meanwhile also offers worldwide coverage. In addition, China now offers global coverage with its Beidou satellite system. The European Union also launched the Galileo, which has recently been used globally, a competing GPS system with a markedly civilian control.

Most current smartphones now offer support for GLONASS, Beidou and Galileo. As a rule, however, they only use the system as a supplement to GPS if a sufficiently strong GPS signal is not available.

We have put together more detailed information on the GPS alternatives for you in a separate guide. The construction of the GPS system was also not uncomplicated. On another page you can read more about the history and technology of GPS.

Background: technology and history of GPS and Co.
Practical information and tips on mobile navigation

Latest news about GPS