It was already nine o’clock in the evening and Janeth still hasn’t come home. Her mother was starting to worry. She kept on calling her child but there was no answer. She was about to panic. She kept uttering these words, “Janeth, where are you?” She was becoming more tense not knowing where her child was.
Parents often want to know the whereabouts of their children to free them from worries and horrific scenes that play in their heads once they start to worry. With the continuous developments in technology, answering the question “Where are you?” is now possible. But how does it work?
Many of you may have heard of the Global Positioning System otherwise known as GPS from movies and television shows. Whenever we hear it, we associate it with navigation and location. One may see a CIA agent holding a GPS device; and in an instant, the agent already knows the location of her asset. Seeing this, one may be lead to think that the process is relatively simple. In reality, it is not.
The GPS system has three components.
First, it has 24 satellites that orbit from a distance of 20,000 km from the earth’s surface. Each satellite would take 12 hours to complete one orbit around the earth.
Each satellite orbiting around the earth has to be detected from any location on Earth. Hence, scientists made six groups, each consisting of four satellites. A specific path has to be followed by each satellite which produces six orbital planes that encompass the Earth.
Second, it requires a receiving device. This device houses a receiver, antenna and the communication tools necessary to send signals to the data center. In each site, an antenna that functions similarly to that of a car radio antenna, gathers the signals.
These signals are transformed into electric currents that are sent to the receiver. The signals from each satellite are then separated into various channels and frequencies. This enables the device to match its internal clock to the GPS time standard.
Last is the data system, which has a monitoring and a controlling function. These are the things responsible for analyzing data received from both the satellites and the receiving devices.
Given the location of the three or four satellites, and by getting the distances of three or four satellites at the same time, the receiver can come up with its height, longitude, and latitude at that moment. In getting the exact location of an object, another mathematical concept is applied. This is known as trilateration or triangulation. This allows the system to determine a position by measuring the distances.
Asking someone where they are may be relatively simple if the person knows their location or if you can reach that person. However, finding out the location of a person or an object is relatively more complex than most people would think.
To accurately determine a location, a person has to utilize a GPS system comprising of a network of satellites, receivers and a ground base which works together harmoniously to produce accurate and reliable information that may even save some people’s lives.