What is GPS: the principle of operation, application, disadvantages

Today artificial satellites of the Earth are actively used in many spheres of our life. Satellite TV and satellite Internet have already ceased to be novelties. The GPS navigation satellite system is becoming the same. What kind of system is it, and what tasks does it solve?

Operating principle

First, let's look at what GPS is. This abbreviation is derived from the English words Global Positioning System - global positioning system. This is the name given to the system of space satellites, which began to be developed as far back as the 1970s by the order of the US military department. In the 80 years she was allowed to use civilians. The GPS system helps to determine the exact location and coordinates of a moving object. The work of satellites is not affected by weather conditions, so the system operates around the clock.

The main advantage of this system is its free. In order to learn and experience what GPS is, you only need to purchase a special receiver and software. The latter is an electronic map of the region in which you are located, as well as the A-GPS program, which is used in cloudy weather. It connects to a special server, which contains information about the coordinates of the nearest satellites. Today, this program is in every car navigator.

How does GPS navigation work? Circular orbits move 24 satellites, each of which makes 2 turns per day and transmits radio signals. Taking them, the GPS receiver calculates its location. First, the difference between the signal arrival time and the reception time is calculated. This is how the distance to the satellite is calculated. If there are at least two of them in the area of the receiver, then it can determine the latitude and longitude on which it is located, and mark itself on the electronic map. When capturing four or more satellites, the receiver software calculates not only the latitude and longitude, but also the speed of the object, the distance traveled and the remaining distance, the time of sunrise and sunset, and many other quantities. The accuracy of determining the coordinates of GPS receivers today is from 5 to 20 m (in height - up to 10 m).

Application area

So, what is GPS, we found out. In which areas can this system be used? Practically in all.

Let's start with the most common and famous wide user. These are car navigators. In fact, these are computers for which a special operating system is used. They already have navigation software installed, which can not be changed without violating the license. In addition to orientation in the urban space, navigators provide a lot of additional opportunities - with their help you can view photos, play music, watch videos, connect to the Internet.

Automobile navigators are actively used not only by ordinary motorists, but also by transport companies. After all, the GPS system allows you to monitor the route of vehicles with cargo and quickly respond to possible delays. If there is a special sensor with this system, you can monitor the fuel consumption.

Another area of application is pedestrian navigation. There are compact navigators that can be used in hiking and walking tours. They are a good alternative to the familiar map and compass. Also, navigators can be built into mobile devices - smartphones. The accuracy of the coordinates in this case is still lower than that of conventional receivers, but manufacturers are actively working on the development of navigation programs.

Speaking of what GPS is, you can not forget about the shortcomings of this system. The quality of signal reception is affected by the density of urban development, the presence of trees with dense foliage, terrestrial sources of radio signals and other factors that create interference. But the main problem is the dependence of the work of satellites on the will of the US military department. There is no guarantee that at one point it will not turn on the noise or simply turn off the civilian sector in any region. Fortunately, at the moment there are already alternative navigation systems, which allow not to "get lost" in this case. This is the Russian GLONASS and the European Galileo. Manufacturers of navigators are also preparing for such extraordinary situations and developing chips that can support all three navigation systems.