How GPS Works
It's technology... and a little bit of magic (maybe)
The Basics: What Is GPS?
GPS (Global Positioning System) is a network of satellites, specifically an American network of satellites.
A GPS Tracker such as Gemstone, doesn't just use the American GPS system, but is compatible with multiple satellite navigations systems (collectively called GNSS).
--- In daily language everyone usually just says "GPS" though ---
For example, our tracker (Gemstone) uses the following systems:
- GPS (United States)
- Galileo (European Union)
- BeiDou (China)
- QZSS (Japan)
This multi-system compatibility improves accuracy and reliability for asset management.
How Your Tracker Determines Its Location
When you're tracking an asset with a GPS tracker, perhaps our Gemstone or Cobblestone, here's how it works:
- Receiving Satellite Signals: Your tracker activates its antenna and receives signals from multiple satellites in view.
- Calculating Distance: By measuring how long it took each signal to arrive (at the speed of light), the tracker calculates its distance from each satellite.
- Trilateration: The tracker uses a mathematical principle called trilateration to determine its exact location.
What's Trilateration you ask? Said very simply: "gathering 3 clues from satellites about where, and using a 4th for time measurements". Read more here... - Sending Data: Once the GPS tracker knows its location, it uses cellular networks (LTE-M, NB-IoT, or 2G) to send the information to a nearby cell tower.
- Sending Data, part 2: The cell tower identifies the tracker's SIM card and service agreement and transmits the location data to a server.
- Viewing Location: The GPS company uses the information on their server and make it available to you through your app, web interface, or dashboard.
Why Signal Issues Happen (Whose fault is it?!)
All GPS trackers are designed to be incredibly reliable and accurate, but... What are the natural limitations to satellite technology?:
Urban Canyons
What are Urban Canyons? The answer = Tall Buildings.
Tall buildings and skyscrapers create what is known as "urban canyons" because the physical structures block or reflect the satellite signals, causing positioning errors or no position at all. The GPS tracker isn't malfunctioning, or not working, but the signal is unable to reach it.
Indoor Locations
The great indoors, not so great for GPS signals.
Our Gemstone GPS tracker does offer indoor tracking, but this is not GPS. Satellite signals are naturally weaker indoors, as structures are in the way of getting the signal to the GPS tracker. The more layers between your tracker and the open sky, the harder it is to get an accurate reading.
Concrete Structures
Ever tried drilling through a concrete wall to hang a photo?
Now image a little thin GPS signal.
Concrete, especially that which is reinforced with metal, is very effective at blocking radio waves from satellites. So if you're parking your car in a parking garage, the GPS tracker will not be able to determine its position.
Weather Factors
A cloud, really?
No not really. But severe weather conditions can sometimes interfere with signal quality and tracking accuracy, though this is less common that other factors.
Why Signal Issues Happen (Whose fault is it?!)
All GPS trackers are designed to be incredibly reliable and accurate, but... What are the natural limitations to satellite technology?:
Urban Canyons
What are Urban Canyons? The answer = Tall Buildings.
Tall buildings and skyscrapers create what is known as "urban canyons" because the physical structures block or reflect the satellite signals, causing positioning errors or no position at all. The GPS tracker isn't malfunctioning, or not working, but the signal is unable to reach it.
Indoor Locations
The great indoors, not so great for GPS signals.
Our Gemstone GPS tracker does offer indoor tracking, but this is not GPS. Satellite signals are naturally weaker indoors, as structures are in the way of getting the signal to the GPS tracker. The more layers between your tracker and the open sky, the harder it is to get an accurate reading.
Concrete Structures
Ever tried drilling through a concrete wall to hang a photo?
Now image a little thin GPS signal.
Concrete, especially that which is reinforced with metal, is very effective at blocking radio waves from satellites. So if you're parking your car in a parking garage, the GPS tracker will not be able to determine its position.
Weather Factors
A cloud, really?
No not really. But severe weather conditions can sometimes interfere with signal quality and tracking accuracy, though this is less common that other factors.
The Complete Picture: Satellites, Cell Towers, and Servers
Satellite navigation explained... to the best of our ability!
Understanding the system can help clarify why GPS tracking and the devices can sometimes face challenges.
- Satellite Connection: Your tracker needs a clear view of the sky to receive signals from multiple satellites to determine its location
- Cellular Connection: Once it knows its position, your tracker needs cellular coverage to transmit this data to Copenhagen Trackers' servers.
- Server Processing: The servers process and store this information, making it available when you check the app.
If either the satellite signals or cellular connection is compromised, tracking may be delayed or temporarily unavailable.
A Note on GPS Accuracy
As may be clear, there are a lot of factors which play a big role GPS positioning and signal strength.
Likewise, these factors also play a large role in the accuracy of your GPS tracker.
In the world of GPS, it is expected that sometimes the distance between your tracker and the app location can be 3 - 30 metres off.
An illustration of how the online and physical location may not always be 1:1
In Summary
GPS tracking is a remarkable technology that allows you to monitor valuable assets and ensure theft-prevention and recovery, but it does have natural limitations (unfortunately, it's not magic after all).
We hope that you have been able to gain a better understanding of how GPS tracking works, which helps set realistic expectations about when and where tracking will be most effective. Rest assured that if you choose to buy a Copenhagen Trackers device, our tracker combines the best of GPS technology with a thoughtful design. To provide the most reliable tracking for everything you don't want to lose.
Environmental factors and even how you place the tracker play a big role in signal strength, accuracy, and the experience. Should you have any issues at all please always get in touch with our customer support, click here.