In modern science, the Global Positioning System (GPS) is a very common service for smartphone users. Maybe you can’t find any people who have smartphones but never use GPS. It’s a rare case. The common GPS service is MAP service such as Google Maps, Apple Maps, We Go or Microsoft Bing Maps.
Going to a new area do not know anything? There are online mapping services to help you. From the surrounding environmental conditions to the distance to a specific destination, the state of traffic jams, Google Maps says. Apple Maps, Google Maps or other mapping services or the latest send or Uber, their success or your advantage – no matter what; there is a magical technology in everything. And that is the Global Positioning System, or GPS for short, without which you might get Google Maps – but you wouldn’t know exactly where you are. Or send / Uber but the driver might have taken a few hours to find you.
While the word “global positioning system” may seem unfamiliar to many, I hope it doesn’t sound unfamiliar to anyone else after saying “GPS”. Some phones also call it “location”. And for the benefit of the new curriculum, nowadays even secondary students should have an idea about what GPS is. But few people know how GPS works. However, I can guarantee that there are many curiosities. Have you ever wondered how GPS works? The purpose of this post is to satisfy your curiosity.
What is GPS?
Judging by the success of the nomenclature or not, the Global Positioning System or GPS is actually an excellent system. To put it more clearly, it is a system made up of at least 24 artificial satellites orbiting the earth. Of course, there are 3 more satellites as a backup – it is not possible to say what happens in distant space! However, according to some estimates, there are a total of 32 satellites in GPS.
But these artificial satellites of GPS are not located together. Rather, they are arranged around the Earth at approximately equal distances (at an altitude of about 12,000 miles) in such a way that all the satellites together send signals to cover every part of the world (even any deep part of the Amazon forest). The whole network has been arranged keeping in mind that you will get at least 4 satellites “with you”.
Who owns GPS? Who sent the GPS satellites?
A south Asian developing country Bangladesh became the owner of its own (Bangabandhu-1) communication satellite last year. Again, there are many countries that do not have a satellite yet. So who sent so many satellites into space for GPS? Who owns them? Google, Microsoft or NASA?
Very good question. In fact, the US government owns these GPS satellites. The Department of Defense sent these satellites into space for military use in the 1960s. Later in the eighties, they made these satellites or the whole GPS system open to the use of all countries around the world or the general public. There are a total of 30 control rooms around the world to monitor GPS satellites, the main one of which is located in Colorado Springs.
Despite such advanced technology, ordinary people rarely used GPS. Back then, only planes, ships, fishing boats or adventurers used this technology with GPS devices. But after the arrival of the smartphone, a small GPS chip was inserted inside the phone. And now GPS is being used extensively in combination with concepts like Google Maps or Uber.
How does GPS work?
Smartphones have a GPS chip to receive GPS signals. It can detect signals coming from GPS satellites. This receiver chip does not transmit any data or transmit it to the satellite.
Of the 24 satellites I mentioned in the beginning, those satellites actually transmit a kind of radio signal 24 hours a day and seven days a week. The GPS chip has the ability to capture the signal that is in your smartphone or car tracker. Nowadays, however, the GPS chip smartwatch is even in the key ring.
GPS satellites are equipped with atomic clocks which give very fine times day after day. And you have a watch on your phone. The signal that satellites send is basically the time it takes to send the signal. Calculates the actual distance between that satellite and your phone from the time your phone generates the received signal and the distance between when your phone receives that signal. GPS basically determines your location from this distance.
But there is a problem here. The problem is that you can’t determine the position of a second thing by the distance between one thing and another. To determine the location where you need to take the distance subject to at least three things.
Giving an example will clear the matter. Suppose your friend tells you on the phone that he is 1 km (or more) directly from the gate of the Jatiya Sangsad Bhaban. If you only hear so much, you will never know where he is. Because he can be 1 km away from the parliament building in any direction. This means that if a circle with a radius of 1 km is imagined around the parliament building, it can be anywhere along the circumference of the circle.
Now, what if he says that he is at the same time one and a half kilometres away from the Prime Minister’s Office? Then his position will be a little clearer to you. Now if you imagine a circle with a radius of 1.5 km around the centre of the Prime Minister’s Office, you will see that this circle intersects the previous circle at two points. That means your friend is in either of these two points. But you did not find your friend’s location.
Now, what if your friend tells you that he is also 500 meters straight from Tejgaon railway station? Then your job is done. If you imagine a circle with a radius of 500 meters around the centre of Tejgaon railway station, you will see that all three circles intersect at a single common point. And that intersection is the Farmgate bus stop. And your friend is actually at the Farmgate bus stop. Isn’t that funny? This calculation is called trilateration.
GPS also works on this principle. Your phone’s GPS chip simultaneously determines its own distance from 3-4 GPS satellites. Your phone usually detects your location with the signals of three GPS satellites, as in the example above. In this way, the more satellite signals you get, the more accurate your location will be. This system works best under the open sky because it is convenient to receive satellite signals.
Combination of GPS and digital maps
However, your GPS does not know the name of your location. He finds out your coordinate point. It knows your two-dimensional position through two points called latitude and longitude (latitude, longitude). You can express every point of the whole world in one or the other coordinate point. The names of the two places may be the same but the coordinates will not be the same. After plotting these GPS coordinate points on a digital map like Google Map, Bing Map or Apple Map on your phone, you can understand where you are. Mapping apps, such as Google Maps, do this plotting.
Does GPS work without the internet?
In fact, there is no obligation to have an internet connection on your phone to receive GPS signals. All you need is the internet to download the graphical map. So if you have downloaded any part of Google Map for offline use, then you can see your own location by turning on GPS without the internet.
What if America turns off GPS?
GPS is just a system for locating. Apart from GPS, there are other alternative methods of knowing the location. However, they are not very common, and not as powerful as GPS.
As I said before, GPS is owned by the US government. Although they have kept it open to the whole world, they can close it if they want to (maybe in a war-like situation).
So Russia has developed a system like GPS which they have named GLONASS. Nowadays you can see the specifications of the smartphone Location: A-GPS with GLONASS. This means that the phone can locate both GPS systems in the US and GLONASS in Russia.
China is also working on its own positioning system called BDS and Europe Galileo.
Mobile phone service providers can also find out your location based on how far your phone is from a tower. In the same way, the location can be determined using the WiFi network.