Today we’ll talk about what GPS is, how this system works. We will pay attention to the development of this technology, its functional features. We also discuss what role interactive maps play in the system.
GPS History
The history of the emergence of a global positioning system, or determination of coordinates, began in the United States back in the fifties when the first Soviet satellite was launched into space. A team of American scientists who monitored the launch noticed that when moving away, the satellite evenly changes its signal frequency. After a deep analysis of the data, they came to the conclusion that, using the 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, and vice versa, the speed and location of a satellite in orbit when determining the exact human coordinates. By the end of the seventies, the US Department of Defense launched a GPS system for its own purposes, and a few years later it became available for civilian use. How does GPS work now? Just as it worked at that time, according to the same principles and fundamentals.
Satellite network
More than twenty-four satellites in low Earth orbit transmit binding signals. The number of satellites varies, but in orbit there is always the right number to ensure uninterrupted operation, plus some of them are in stock, so that in the event of a breakdown, the first ones take over their functions. Since the service life of each of them is approximately 10 years, new, modernized versions are launched. The rotation of satellites occurs 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 associated with the main focal point in the United States.
How does a GPS navigator work?
Thanks to this network, you can find out the location by calculating the delay of the signal from satellites, and using this information to determine the coordinates. How does GPS 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 functions. Actually, the principle of the navigator’s work is based on a long-used simple navigation scheme: if you know exactly where the marker object is most suitable for the role of a landmark and the distance from it to you, draw a circle on which indicate your location with a dot. If the radius of the circle is large, then replace it with a straight line. Draw several of these stripes 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 from your location of about 18 thousand km. Although their rotation in orbit occurs at a tremendous speed, the location is constantly monitored. Each navigator has a GPS receiver that 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 time zone (exact time). By the way, information about the exact time is the most necessary for obtaining data about your coordinates: the calculation of the time interval between the transmission 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 satellite in orbit is calculated.
Difficulty synchronization
Based on this principle of navigation, we can assume 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. The main problem is the GPS receiver's clock, which does not allow for sufficient synchronization with satellites. The reason for this is the difference in the display of time (on your navigator and in space). The satellites contain expensive high-quality atomic-based watches, which allows them to count the time with extreme accuracy, while such chronometers cannot be used on ordinary receivers, 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 to the side!
Third marker
So the developers decided to leave the usual technology of quartz watches in GPS-navigators and go a different way, to be more precise - use instead of two satellite landmarks - three, respectively, the same number of lines for the subsequent intersection. The solution to the problem is based on a brilliantly simple solution: when all the lines intersect with the three marked markers, even with possible inaccuracies, a zone is created in the shape of a triangle, the center of which is taken in the middle - your location. It also allows you to identify the time difference between the receiver and all three satellites (for which the difference will be the same), which allows you to adjust the intersection of lines exactly in the center, in other words, it determines your GPS coordinates.
Single frequency
It should also be noted that all satellites send information to your device at the same frequency, and this is quite unusual. How does a GPS navigator work and how does it perceive all information correctly if all satellites continuously and simultaneously send information to it? Everything is pretty simple. To determine themselves, transmitters on the satellite also send standard information in the radio signal, in which the encrypted code is located. It reports the maximum characteristics of the satellite and is entered into the database of your device, which then allows you to verify data from the satellite with the database of the navigator. Even with a large number of satellites in reach, they can be quickly and easily identified. All this simplifies the entire circuit and allows the use of smaller and weaker receiving antennas in GPS navigators, which reduces the cost and reduces the design and dimensions of the devices.
GPS maps
GPS maps are downloaded to your device separately, since you yourself influence the choice of the area on which you want to move. The system just sets your coordinates on the planet, and the function of the maps is to recreate the graphic version on the screen, on which the coordinates are plotted, which allows you to navigate the terrain. GPS how does it work in this case? For 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 configure the road from point A to point B as informatively and with all amenities as possible: what sights you will pass, the shortest way to your destination, voice assistant indicating the direction and others.
Additional GPS equipment
The GPS system is used not only to show you the desired path. It allows you to track an object on which there may be a so-called beacon, or GPS tracker. It consists of the signal receiver itself and the transmitter based on gsm, 3gp or other communication protocols for transmitting information about the location of the object to service centers that monitor. They are used in many industries: security, medical, insurance, transport and many others. There are also car trackers that connect exclusively to the car.
Traveling without problems
With each passing day, the values of the map and a permanent compass are fading ever farther into the past. Modern technology allows 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 science fiction about a century ago has become a reality today, and almost everyone can take advantage of it: from the military, sailors, and airplane pilots to tourists and couriers. Nowadays, the use of these systems for commercial, entertainment and advertising industries is gaining great popularity, where every entrepreneur can indicate himself on the global map of the world, and it will be quite easy to find him. We hope that this article has helped everyone who is interested in GPS - how it works, by what principle coordinates are determined, what are its strengths and weaknesses.