GPS TrackerAugust 20, 2019
GPS tracker IMPORTANT: A GPS tracker might not work the way you think it does.That’s why it’s important that you read through this post to get a general understanding of how a GPS tracking device works. GPS tracking only works
IMPORTANT: A GPS tracker might not work the way you think it does.That’s why it’s important that you read through this post to get a general understanding of how a GPS tracking device works.
- GPS tracking only works outside in line-of-sight to the satellites.
- There are a lot of different types of satellites, but none of them is owned by the tracking device providers/manufacturers.
- The tracker needs to be in direct line of sight to minimum 3 different satellites to be able to triangulate a location. If you are outside, but close to a building blocking half the sky, you might not have line of sight to 3 different satellites from your GPS tracker (explained below).
- WI-FI tracking is included in many GPS-tracking devices today. When tracking on WI-FI, your device is using the routers MAC-address to locate your device. This is only an address, so device might be outside or inside a house/building on this address or somewhere close, meaning it’s not always 100% accurate.
- LBS is a third way of showing you location, which is used in many GPS-trackers today. LBS tracking is just a distance from the nearest radio tower. The accuracy of this location might vary from 5m if you are close to many radio towers which can triangulate the location, up many thousands of meters if you are not. It is usually used as a back up solution if you can’t get GPS signals or WI-FI signals.
1: A GPS tracker gets its location from satellites by triangulating the location of 3 satellites.
The satellites knows their location in space, and know the distance between themselves. They then meassure the distance between them and your GPS tracker, so the the satellites will give you the tracker’s location with great accuracy.
There are many different Satellites that gives you location. GPS is the American satellites, while GLONASS is the Russian satellites. We also have European satellites called Galileio and Chinese satellites called BeiDou.
All these satellites will give you “GPS location”. But there number of satellites and how it work will influence both the accuracy of your location and when you get a location reading.
24 GPS satellites:
The GPS constellation requires a minimum of 24 operational satellites. And since the world is a globe you will only see half the sky at any given place in the world. The GPS satellites on the other side of the world you will not be able to see.
So in a GPS tracker view you will have access to 12 satellites, where most of them will be on the horizon. This means that right above your head, you will usually have access to about 4-5 satellite trackers. This is more than enough to get a location reading!
But if you’re in the city, with a big building blocking half the sky and buildings blocking the horizon, you might not able to get a direct line-of-sight with at least 3 satellites. So this is why the GPS trackers have additional tracking options for indoor tracking.
A fun fact about these satellites:
When Albert Einstein discovered Special and General relativity in the early 20th Century, he also made a huge impact in how the GPS system works. Special relativity tells us that moving clocks run slower with respect to a stationary observer. This becomes more and more obvious, the closer you are to the speed of light. GPS satellites don’t travel at the speed of light, but they do move so fast in comparison to the observer, that the effect is measurable. Then we have General relativity telling you the closer you are to a heavy mass, such as Earth, the slower time will move for you. This means that the clocks on a GPS satellite will run faster, relative to clocks on the ground. If this “correction” was not made, the GPS position would be several kilometers wrong after only a few hours.
2: Satellites only work outside.
The Satellites need to be visible to the tracker. To get location from satellites only you need a minimum of 3 satellites to triangulate your location. This is why many devices, including our Tail it GPS trackers, uses WI-FI routers for indoor and dense area tracking. To get location from WI-FI routers, you need a WIFI chip-set in your tracker. This is similar to the GPS tracking chip-set. The WI-FI routers works like a satellite, since they know their own location (their MAC address). But this is not as accurate as fetching location from satellites. This is because the router only knows their address and not exact location. But WI-FI location gives you a location with fairly good accuracy, since it shows you the address the tracker is on. It’s important to understand that your GPS tracker does not login to satellites or WI-FI routers, but calculate location from their known location.
So you don’t need any WI-FI passwords or any login information to get location based on the routers.
3: LBS (telecom antennas) is used as Area navigation.
A third option for tracking locations within the GPS tracking devices are with the use of LBS (local base stations). This is used if there are no signals from either satellites or WI-FI routers. Like in basements or in the middle of concrete buildings with no signals. In these cases you will often still get a LBS signal. LBS will give you an approximate location even when you get signal from only 1 or 2 antennas. It will not be very accurate, but it will give you an indication. If there are more LBS antennas in your area, the location is more accurate. When you get closer to the surface or outside, WI-FI routers or satellites will help triangulate the location again.
4: Bluetooth trackers
Todays market of trackers can be very confusing. The biggest market today is made of Bluetooth trackers. They are trackers that only works close to your mobile phone. Bluetooth was first developed by Ericsson as a system for sending wireless data between units. Today the new Bluetooth 5.1 should be able to send data up to 100m between the devices. This is great if you have lost something at home, in your car or in other limited areas. The problem with Bluetooth trackers is when the device you’re tracking is out of range. Its therefore important to understand that the Bluetooth trackers only work within a limited range close to your mobilephone.
5: Different kind of GPS trackers
There are many kind of GPS trackers. That’s why it’s important to have a general understanding on how these trackers works to understand what best fits your needs. Under is a short list of what types of trackers there is:
This is GPS tracking of your assets. So you will need all functions as mentioned above for them to be able to give you location at all times with maximum battery life of the GPS tracker. The size of the things you’re tracking will restrict the size of the tracker you need. The bigger the tracker you can use, the longer battery time you’re able to get.
Tracking your pets is pretty much like tracking any other asset, but size is always an issue. Getting the smallest possible GPS tracker including both GPS, WIFI and LBS is your goal. Please check our cat tracker and dog tracker articles to read more about tracking your pets.
GPS Fleet management
To operate a GPS fleet management you need an additional web application with customized updates to your fleet. We’re currently working on writing an article about the fleet management, so an update will come soon.
6: GPS location APP
The last thing that is very important when choosing a GPS tracker will be the interface where you handle all the locations. After all, the tracker is just a dead unit showing you location whenever the interface request it.
What type of information is needed. And what type of information you can get from the tracker is most important. That is why we wrote this big article about mobile tracker. Simply to go in depth on all the important things regarding the interfaces like handling, security and sharing of location.
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