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How Does GPS Tracking Work?

What Is GPS Tracking?

The Global Positioning System, or GPS, was first designed for military applications, but in decades since has seen its uses proliferate—including quite commonly as part of GPS tracking. But what is GPS tracking, and how does GPS tracking work? Those are two of the key questions we’ll be answering today, as well as how GPS is often used.

Let’s start by looking at the top 15 uses of GPS.

Top 15 Uses Of GPS

  1. Position locating. GPS tracking of locations is one of the biggest and most common GPS applications, whether hiking, in a car (think of those mapping software devices you might use while driving, for instance) or even communication between individuals or vehicles.
  2. Emergency support. If you have OnStar or another built-in emergency support system in your car, that works in part by sharing your GPS location with emergency response services. If you are injured while hiking and have an emergency beacon or other GPS tracker device, a similar thing happens—you are able to get help because your GPS location is shared with emergency response teams such as search and rescue. This is often true even when you can’t actually share any location details because your phone or transponder shares those details automatically.
  3. Theft prevention and/or recovery. One of the reasons for installing a GPS tracker in your car can result in a lower insurance rate is because they’ve been proven in assisting with theft recovery.
  4. Surveying and mapping. GPS technology makes mapping and surveying substantially cheaper and more cost-effective, regardless of what the project is—transportation projects (mapping highways or overpasses, for instance), agriculture (crop planting and planning), and more.
  5. Law enforcement tracking. For many law enforcement agencies, GPS tracking can be a great way to keep an eye on suspects without requiring an agent or officer tail them. GPS information can also be used as evidence, such as confirming someone’s alibi, or proving they’ve lied about where they’ve been, for instance.
  6. Pet location. GPS microchips can help you find your lost animal should they become lost, just as they can help reunite them with you if someone else happens to find your pet.
  7. Troop monitoring. When it comes to covert operations, for instance, GPS tracking can be one of the best ways for commanders and operation leaders to monitor every individual’s positions—which in turn can help them keep soldiers safe.
  8. Eldercare. Whether via a necklace that allows geriatric patients to call for help when they fall or GPS watches, GPS tracker technology is rapidly becoming a more important part of caring for elderly patients, both in-home and in specific care settings such as hospitals or assisted living centers.
  9. Mining. When it comes to mapping mineral rights, deposits, or even ore lines, GPS tracking is a major part of helping mining companies work efficiently.
  10. Art security. Much like GPS tracking can help limit car theft, GPS tags are often attached to major pieces of art (some of which may be valued in the nine-digit range, for instance) to help ensure their security.
  11. Solo adventures. Whether hiking or otherwise adventuring solo, it is often not a bad idea to have GPS tracking so that others can find you should something happen—or if you need to call for help.
  12. Backpacking. Waypoints on a GPS device can help ensure you are able to follow your backpacking route, and as noted previously, having a GPS tracker can help others find you should it become necessary.
  13. Treasure-seeking. While this could refer to such adventures as geocaching, real-life treasure hunters also make use of GPS to search for long-lost treasure.
  14. GPS fleet tracking. As we’ve noted elsewhere, GPS fleet tracking systems can help ensure efficient business operations, such as better route management, fueling processes, and more.
  15. Aeronautics. Most planes rely heavily on GPS to maintain their assigned routes, including their elevation and flight path. And those black boxes you always hear about when a plane goes down? Include a GPS tracker so investigators can look at the exact flight path.

Of course, there are hundreds of other GPS applications, too; these are just some of the most common. But knowing some of the ways GPS is used isn’t the same as understanding how GPS tracking works—so let’s spend more time looking at each part of the GPS tracking process, starting with how GPS determines a location. 

How GPS Determines A Location?

Okay, so there are clearly lots of uses for GPS and GPS tracking. But how does GPS tracking workhow does GPS determine your location, for instance?

The root solution lies in something called triangulation. Wherever you are on earth, there are multiple GPS satellites above you, and as long as you have clear lines to at least three of them (though, ideally, for best location verification you would have access to four or more).

We’ll look at how triangulation works with a little more detail in the next section, but the basic idea is that once multiple satellites have estimated your location based on distance from you to the satellite, your GPS tracking device can pinpoint your location by using all of that data. Let’s look more closely at triangulation so you can see what we mean.

What Is GPS Triangulation?

Triangulation is a mathematical process for determining an object’s location based on the distance from other objects. How does GPS tracking work? Why, via triangulation. When it comes to GPS triangulation, the goal is to determine your precise location based on the distance to each of the satellites—at least three for triangulation.

Let’s give our three satellites each a name. We’ll call them satellite A, satellite B, and satellite C. Because GPS satellites operate on atomic clocks, noting the difference between the time at which a signal is sent from satellite A and when that signal is received by your device can determine the distance between the satellite and your GPS tracker receiver. Of course, knowing the distance isn’t enough to determine a location; that’s where the other satellites come into play.

Knowing the distance between your GPS tracker receiver and satellite A is a start, but knowing the distances to satellite B and satellite C allows your receiver to use triangulation to determine the precise location.

But what exactly does that mean? Think of it like Venn diagrams. If your receiver knows you are 1112 miles from satellite A, for instance, you can draw a circle of locations that are that distance from satellite A. If you also happen to know that you are 1372 miles from satellite B, suddenly you have a much smaller number of locations that are both 1112 miles from satellite A and 1372 miles from satellite B. By the time you add a third satellite, you should be able to pinpoint the location; adding a fourth satellite just helps counter for topographical features, elevation, and any potential error, but isn’t strictly necessary for fairly accurate triangulation.

How Many Satellites Are Used For GPS?

Here’s the thing: You should always have access to at least three or four GPS satellites, no matter where on earth you are—because the GPS network contains a bunch of satellites: 31, to be precise.

Why so many? Well, let’s take another look at why you need at least three satellites—and ideally four—to get a good lock on your position. This will help us answer how does GPS tracking work, as it will help you better understand how the parts of the system work together.

First, keep in mind that these satellites are generally around more than 10,000 miles above the earth’s surface; they’re a long way away. Second, because they make two orbits per day, they’re moving incredibly quickly. These means, however, that most places on earth can generally count on 6 satellites in view at any given time.

As noted previously, your GPS tracker receiver gets data from each of the satellites that the receiver how far away the satellite is (based on the time the signal took) and then uses triangulation to determine location—allowing the GPS tracker receiver to determine your position in three dimensions: latitude, longitude, and altitude.

One complication we didn’t address earlier: In order to accurately calculate the time it took for those GPS signals to reach your receiver, the receiver needs to know the current atomic clock time. GPS tracker receivers cannot feasibly include an atomic clock, however, which is why a fourth satellite can help the receiver sold for the exact time. (This is why truly accurate triangulation actually requires four satellites, as opposed to three.) As a result, if only three satellites are available, your GPS tracker receiver may make assumptions about your elevation that may or may not be accurate; in practical terms, this means that your GPS location is more likely to be off in the mountains if you can only get a lock on three satellites.

Keep in mind, too, that current GPS tracker receivers will typically track all of the available satellites, but only use the closest three or four to determine your position.

How Does The GPS Work In A Car?

Odds are you’ve never actually thought about how the GPS tracker and navigation system in your vehicle works. Really, have you ever asked how does GPS tracking work in your car? At most, maybe you’ve thought it works with a central system of information. (And it’s true, it does require a central mapping directory—but it also requires advanced technology and the GPS satellite system.)

As we noted previously, there are 31 satellites in the GPS—Global Positioning System—network, and at any given time, odds are good that you are within a “line of sight” of 6 of them. (Though, given that they’re regularly orbiting at least 10,000 miles above the earth’s surface, you’re hardly going to see them.)

Your car uses a receiver to connect to at least three—and ideally four—of those satellites to triangulate your location, then uses your car’s on-board diagnostics and sensors to determine more information, including the direction you are pointing, to help provide directions based on where you want to go and your current location in conjunction with the mapping software onboard your unit.

How Does GPS Tracking Work On Cell Phones?

And not just GPS tracking, but also AGPS—Assisted GPS. Both are incredibly important when it comes to tracking where your phone is, especially when it comes to phone features that require knowing where you are, features like geo-tagging photos or using maps, for instance.

Sure, there are some downsides to your phone knowing where you are at all times, but most of the time, it really does work in your favor. And while that cell phone GPS tracking is sometimes the same as GPS tracking in any other device—a receiver in your phone coordinating with GPS satellites to determine your location—it is more and more frequently AGPS that is used to determine your phone’s location.

GPS uses the satellites we’ve referenced previously as well as triangulation to determine your location. AGPS, however, is often a better strategy for your phone. For one, traditional GPS is often slow; it can take a minute or longer to get a lock on your position, for instance. For two, it can require more data as well as be obstructed by tall buildings and other obstructions, which can be a problem in cities.

Assisted GPS, however, adds cellular location data courtesy the cell towers your phone is using for service, using three more cell towers to triangulate your location. Your phone may use both sets of data—GPS and AGPS—to best determine your location and adjust accordingly. Even better, AGPS is already part of your cellular data plan, so it doesn’t cost you anything extra.

Of course, AGPS doesn’t always work; you need good service (at least three cell towers in range of your phone). But when it does, it’s often a better answer, and as a result, your phone will likely use AGPS rather than just the GPS network for location tracking. So how does GPS tracking work on your phone? The truth is, it’s often a combination of AGPS and GPS.

How Do No Monthly Fee GPS Trackers Work?

Of course, not all GPS trackers require cellular service. For instance, many no monthly fee GPS trackers work by storing data which is then later recovered when the GPS tracker device is retrieved. How does GPS tracking work if it isn’t uploaded in real time?

The truth is, it works in the same way. The GPS tracker simply stores the location data until the device is retrieved later, rather than uploading that data via a cellular network as real time GPS trackers work.

There are three different kinds of GPS trackers: real-time (which we’ll discuss shortly), on-demand, and passive. Most no monthly fee GPS trackers are passive, meaning they just store data, rather than share it via a cellular network.

Instead, passive GPS trackers use a data logger; when you retrieve the device later, you can usually just plug that data logger into your computer via a USB drive and see all of the GPS data.

How Do Real Time GPS Trackers Work?

Of course, passive GPS trackers aren’t the only kind of GPS tracker. On-demand and real-time GPS tracker devices both require active cellular connections; the difference is often they are accessible from a third-party site (such as an online site you might log in to).

So how does GPS tracking work when it comes to real time GPS tracker devices? Unlike passive or on-demand devices, real time GPS tracker devices are always available, so you can always check in on a device’s location. This means there’s never a delay in getting the information you need from the GPS tracker. Real time GPS tracker devices can also provide a great deal of other information, including speed, engine stops, idling time, miles traveled, even exact routes taken. Some real time GPS tracker options even include geofencing and alarms, giving parents or business owners a better handle of their children or employees.

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