Will Smartphones Replace GPS Navigators?
GPS is one of the most fantastic utilities ever developed by man. GPS will feature in history alongside the invention of the nautical chronometer. This device allowed sailors to graphically depict their course with an accuracy that greatly developed navigation and was the main cause of the huge waves of migrations of the 19th century.
The Global Positioning System (GPS) is a satellite navigation system. It consists of a network of 24 satellites that have been put into orbit. Like many other high-tech things, GPS was developed by the US military. Its concept originated in the late 50s, but the first test satellite was launched only in 1973, and the first functioning in 5 years. The last 24-satellite to form the final network was launched in 1994. In addition to the main satellites, there is also a network of backup satellites that allow you to increase positioning accuracy.
GPS was originally intended for military purposes only. This may still be the case today, if not for the 1983 incident. Then the Boeing 747, owned by the South Korean airline Korean Air Lines, deviated from its route and was shot down by a Soviet fighter. President Ronald Reagan has since authorized partial use of GPS for civilian purposes. However, with a significant limitation in accuracy. In 1989, Magellan introduced the first handheld GPS receiver. In 2000, all restrictions on the use of GPS were lifted. Now GPS works in all conditions and answers five questions simultaneously:
- "Where am I?"
- "Where am I going?"
- "Where are you?"
- "What's the best way to get to you?"
- "When do I get there?"
Russia, by the way, has its own satellite navigation system GLONASS, which was also originally created as an exclusively military technology, which later became available to civilian users.
How does a GPS receiver determine location?
GPS satellites orbit the Earth twice a day in very precise orbits. They are constantly sending signals to Earth. GPS receivers take them and use them to calculate the location. In fact, the device determines the difference between the time the signal was transmitted by the satellite and when it was received. This is the difference between the GPS receiver and how far away the satellite is. After receiving signals from several satellites and measuring the distance between them, the device finds the location of the object and shows it on its electronic map.
In order for a GPS receiver to determine latitude and longitude, i.e. the 2D position, it must receive a signal from at least three satellites. With a signal from four or more satellites, the receiver can determine the 3D position of the user (latitude, longitude, and altitude above sea level). Once this position has been established, the GPS device can calculate other information – speed, distance traveled, how much more to the destination, how long to get there and much more.
GPS on a cell phone
Modern technology has greatly simplified the life of the ordinary user. Now the problem is navigator For car or hiking often does not occur – most smartphones, presented, for example, in the catalog Aport.ru, already have the function of GPS. Moreover, with the advent of A-GPS technology, the global positioning system appeared in the mobile phone. GPS and A-GPS are similar except for one detail. In order to more accurately determine the location of the object, a GPS device must have a large number of receivers, and sensitive ones. This will allow you to work with more satellites and receive more signals. But the main disadvantage of such GPS devices is their high cost. This problem is solved by A-GPS. This technology calls for help from GPRS or another internet connection. From time to time, the device, in order to accurately determine the current location, seeks information from the service provider’s network. At the same time, high accuracy of receivers is no longer necessary. The only drawback of A-GPS technology is that it cannot use any of the backup satellites. But this innovation can still significantly squeeze the classic navigators on the market. However, the latter still have more fans.