Today we will talk about what GPS is, how this system works. Let's pay attention to the development of this technology, its functional features. We will also discuss the role interactive maps play in the system.
The History of GPS
The history of the emergence of a global positioning system, or determining coordinates, began in the United States back in the distant 50s when the first Soviet satellite was launched into space. A team of American scientists who monitored the launch noticed that as the satellite moved away, it evenly changed its signal frequency. After a deep analysis of the data, they came to the conclusion that with the help of a satellite, in more detail, its location and the emitted signal, it is possible to accurately determine the location and speed of a person on earth, as well as vice versa, the speed and location of a satellite in orbit when determining the exact person's coordinates. By the end of the seventies, the US Department of Defense launched the GPS system for their own purposes, and a few years later it became available for civilian use. How does the GPS system work now? Exactly as it worked at that time, according to the same principles and foundations.
Satellite network
More than twenty-four satellites in Earth orbit are transmitting radio anchors. The number of satellites varies, but there are always the right number in orbit to ensure smooth operation, plus some of them are in reserve so that if the first one fails, they will take over their functions. Since the service life of each of them is approximately 10 years, new, upgraded versions are being launched. Satellites rotate in six orbits around the Earth at an altitude of less than 20 thousand km, it forms an interconnected network, which is controlled by GPS stations. The latter are located on tropical islands and are connected to the main coordination center in the USA.
How does a GPS Navigator work?
Thanks to this network, you can find out the location by calculating the delay of the signal from the satellites, and using this information to determine the coordinates. How does the GPS system work now? Like any navigation network in space, it is completely free. It works with high efficiency in all weather conditions and at any time of the day. The only purchase you should have is the GPS navigator itself or a device that supports GPS features. Actually, the principle of operation of the navigator is based on a long-used simple navigation scheme: if you know exactly the place where the marker object is located, which is most suitable for the role of a landmark, and the distance from it to you, draw a circle on which mark your point with a dot.location. If the radius of the circle is large, then replace it with a straight line. Draw several such strips from your possible location towards the markers, the point of intersection of the lines will indicate your coordinates on the map. The above satellites in this case just play the role of these marker objects with a distance of about 18 thousand km from your location. Although they orbit at great speed, their location is constantly tracked. Each navigator has a GPS receiver, which is programmed to the desired frequency and is in direct interaction with the satellite. Each radio signal contains a certain amount of encoded information, which includes statements about the technical condition of the satellite, its location in Earth's orbit and the time zone (exact time). By the way, information about the exact time is the most necessary for obtaining data about your coordinates: the ongoing calculation of the length of time between the return and reception of the radio signal is multiplied by the speed of the radio wave itself and, by short-term calculations, the distance between your navigation device and the satellite in orbit is calculated.
Synchronization issues
Based on this principle of navigation, it can be assumed that to accurately determine your coordinates, you may need only two satellites, based on the signals of which it will be easy to find the intersection point, and in the end - the place where you are. But, unfortunately, technical reasons require the use of another satellite as a marker. homethe problem lies in the clock of the GPS receiver, which does not allow sufficient synchronization with the satellites. The reason for this is the difference in the display of time (on your navigator and in space). Satellites have expensive high-quality atomic-based clocks, which allows them to keep time with extreme accuracy, while conventional receivers simply cannot use such chronometers, since the dimensions, cost, and complexity of operation would not allow them to be used everywhere. Even a small error of 0.001 seconds can shift the coordinates by more than 200 km!
Third marker
So the developers decided to leave the usual technology of quartz watches in GPS navigators and take a different path, to be more precise - use three, respectively, the same number of lines for the subsequent intersection instead of two satellite landmarks. The solution to the problem is based on an ingeniously simple way out: when all the lines from the three designated markers intersect, even with possible inaccuracies, a zone is created in the form of a triangle, the center of which is taken as its middle - your location. It also allows you to detect the difference in time between the receiver and all three satellites (for which the difference will be the same), which allows you to correct the intersection of the lines exactly in the center, in other words - this determines your GPS coordinates.
Single frequency
It should also be noted that all satellites send information to your device on the same frequency, and this is rather unusual. Howdoes a GPS navigator work and how does it perceive all the information correctly if all satellites continuously and simultaneously send information to it? Everything is pretty simple. To determine themselves, the transmitters on the satellite also send standard information in the radio signal, which contains an encrypted code. It reports the maximum characteristics of the satellite and is entered into the database of your device, which then allows you to check the data from the satellite with the database of the navigator. Even with a large number of satellites in range, they can be identified very quickly and easily. All this simplifies the whole scheme and allows the use of smaller and weaker reception antennas in GPS navigators, which reduces the cost and reduces the design and dimensions of devices.
GPS maps
GPS maps are downloaded to your device separately, as you yourself influence the choice of the area where you want to move. The system only establishes your coordinates on the planet, and the function of the maps is to recreate on the screen a graphical version on which the coordinates are applied, which allows you to navigate the terrain. How does GPS work in this case? Free, it continues to remain in this status, cards in some online stores (and not only) are still paid. Often, separate applications for working with maps are created for a device with a GPS navigator: both paid and free. The variety of maps pleasantly surprises and allows you to set up the road from point A to point B as informatively as possible and with all the amenities: what sights you will pass, the shortest wayto the destination, voice assistant indicating the direction and others.
Additional GPS equipment
GPS is used for more than just pointing you in the right direction. It allows you to track an object, which may contain a so-called beacon, or a GPS tracker. It consists of the signal receiver itself and a transmitter based on gsm, 3gp or other communication protocols for transmitting information about the location of an object to service centers that exercise control. They are used in many industries: security, medical, insurance, transport and many others. There are also car trackers that connect exclusively to the car.
Travel without problems
With every passing day, the values of the map and the permanent compass go further and further into the past. Modern technologies allow a person to pave the way for his journey with minimal loss of time, effort and money, while seeing the most exciting and interesting places. What was a fantasy about a century ago has become a reality today, and almost everyone can take advantage of it: from the military, sailors and aircraft pilots to tourists and couriers. Now the use of these systems for the commercial, entertainment, advertising industries is gaining great popularity, where every entrepreneur can point himself on the global map of the world, and it will not be difficult to find him at all. We hope that this article has helped everyone who is interested in GPS - how it works, on what basis the coordinates are determined, whatits strengths and weaknesses.
