Now that Global Positioning System (GPS) has been deployed worldwide and is accessible from almost every smartphone, it’s about time we learn how it actually works. Firstly, let’s dig deep into some history of cell phone location tracking. Before GPS, the only way to track mobile phones was with triangulating the cell phone location which was a rather long process. Then GPS was brought to light, which is actually a US-based satellite navigation network that consists of 24 different satellites. These satellites are maintained by the Department of Defense and were initially designed to be used for military purposes only. However, in 1980, US government decided to lift all the restrictions from GPS, making it available for general public. Now, users are able to utilize GPS tracking service on their mobile phones 24/7, which is incredibly helpful.
GPS and Satellites
As mentioned above, there are a total of 24 satellites orbiting the earth and they are at the distance of 12,000 miles above planet. These satellites travel at the pace of 7,000 miles per hour and are powered by solar energy. All of the satellites have their own battery backup that allow them to work even during the solar eclipse. Each satellite has a life cycle of ten years and they are then replaced with a new one.
How Does GPS Signal Work?
First of all, GPS satellites transmit two low power radio signals which are designated as L1 and L2. L1 signal is transmitted at 1575.42 MHz (UHF) and is designed for civilian use only. This signal travels with the light of sight, hence penetrating clouds, plastic and glass. However, the unusually solid objects will block its way. Each signal contains ephemeris information, pseudorandom code and almanac data. Ephemeris information consists of different details as it checks whether the satellite is operational or not, it provides current time and date and finally, it contains portion of the GPS signal used to determine the position. Almanac data’s job is to inform the receiver of the expected location of satellite throughout the day. The pseudorandom code contains ID for the satellite that is doing the information transmitting.
How Accurate is GPS?
With multi-channel designs, GPS receivers nowadays provide almost perfect results. You are able to know the location of the phone in an instant. There are some instances where weather may affect the exact location a bit, but overall performance and accuracy of GPS tracking is rarely affected. Usually, the result shows that the person is within fifteen feet of the shown location. However, when there are a lot of factors affecting the communication then the results will vary and can show location which is 50 feet far from the actual smartphone location. These instances however, are pretty rare.