Today, the average consumer drone comes with a slew of GPS-enabled features. These are put in place by drone manufacturers to help pilots navigate their drones and achieve a host of other things.
But drones were not always built like this.
There was no GPS module installed, and like most remote controlled aircrafts, all pilots could hope for was a remote control and receiver to operate their devices.
As you can imagine, it took skill and expertise to manage these early drones — more skill than the average newcomer could boast of.
How Does GPS Work on a Drone?
Ultimate control of a drone rests in the hands of the pilot. However, GPS makes piloting a drone easier — significantly, in many instances.
Some of the features which drone operators have GPS to thank for include:
- Position Hold: this allows your drone to maintain a fixed altitude at a location.
- Return to Home: the drone remembers the spot from where it took off, and to which it would automatically return once the “return to home” button is pressed.
- Autonomous Flight: this allows pilots to map a flight path for their drones by establishing GPS waypoints that define the trajectory. Once launched in this mode, your drone is capable of flying along the predetermined path on autopilot.
Simply put, drones would not be the beloved devices they are today without the GPS system involved. But how does GPS work in a drone?
To better understand the merger between drones and GPS, one has to first acquaint themselves with what GPS is and how it works in general.
The Global Positioning System (GPS) is a satellite system that uses a radio receiver to receive signals from orbiting satellites in order to determine parameters like position and speed.
There are other forms of navigation (any sailor or aircraft pilot worth their salt would tell you that), but GPS is by far the most accurate, providing position information to within a few meters of accuracy.
The most advanced GPS systems today can even boast of accuracy within a few centimeters.
Originally created by the US military, GPS was first of all used as an accurate navigation system to guide intercontinental ballistic missiles. Before GPS, the military had a hard time getting accurate target coordinates for its missiles that were being launched from submarines. GPS was developed as an answer to this problem.
Today we are able to integrate GPS into ever smaller devices as the technology gets cheaper, smarter, and more accessible from any corner of the planet.
So how does GPS help your drone ‘know’ its position on the ground? It uses the concept of triangulation.
GPS Position Triangulation
Triangulation is a procedure whereby the location of a radio receiver can be determined by measuring the radial distance of the received signal from different radio signal sources.
In simpler terms, it is a way of locating an object by using the location of other things.
Your drone is a radio receiver, because it communicates with radio signals (conversely your controller is a radio transmitter that sends out signals).
In the case of satellite navigation like GPS navigation, the other radio signal sources are satellites in orbit. One GPS satellite sends your drone a radio signal, and then notes the position, and then another satellite does same, and then another, after which a likely position is determined at the intersection.
It is a pretty accurate system that is used across many industries for various purposes, including your drone.
Distance from Time
In theory, the distance from the GPS satellite to the location of your drone can be calculated by merely taking note of the time which the three or four satellites send their radio signals to the drone.
This should be easy given that we know signals from GPS satellites are time-stamped and we also know the location of each satellite, as well as the speed of radio signals in space.
But things get complicated because of two factors:
- Radio waves only travel at the speed of light in a vacuum and will change their speed once they enter the Earth’s atmosphere and head for your drone.
- Your drone’s clock could be set slightly (or entirely) wrong.
The second point especially makes it extremely difficult to calculate the distance between satellite and drone based solely on the time the drone received the signal.
Unlike the GPS satellites that run on atomic clocks that have an accuracy of one second in 100,000 years, your drone runs on regular run-of-the-mill timing. One second off could throw the location off significantly.
If your drone was travelling at 50 km/h, your drone could travel almost 14 meters in a one second timeframe. An incorrect measurement of 14 meters wouldn’t make for great GPS features!
How your drone goes about compensating for time difference is entirely out of your hands and in the hands of the manufacturers of GPS-enabled devices.
Does Your Drone Need GPS?
The answer to that depends on what you intend using the drone for. You do NOT need a GPS module installed in your drone to fly it. In fact, many drone models don’t have a module installed.
By keeping your device within your line of sight, you can fly it any way you can and be done with it.
But that’s about all you can do. Fly.
If your drone is meant for more sophisticated work, like 3D mapping, surveying, agricultural input, then a GPS module is an absolute must-have.
In addition to that, many of the cool features that come with consumer drones are GPS enabled. For example:
- The display on your controller or mobile that reads the correct position of your drone at all times, and also the position of the drone in relation to you the pilot, works thanks to GPS.
- GPS enables you to locate and record the home point feature that enables your drone to return to that point in case of an emergency like a loss in signal or depleted batteries. Pilots can also activate this feature by pushing the designated button on the controller or the app.
- Obstacle avoidance systems which is a key feature in some of the best drones available today relies on GPS. Drones equipped with this GPS feature are able to sense and avoid obstacles during automatic flights and Follow Me flights. Some drones like the Mavic Air even slow down when they sense obstacles, retreat, and then fly over them before resuming flight at their previous speed.
- Geofencing is a feature installed by most drone manufacturers to ensure drones are flown only where they are supposed to. And, yes, they rely on GPS too.
- Drone navigation waypoints are another GPS feature that has found use in many industries like agriculture and surveying. This is an advanced feature that enables drones to autonomously fly to predetermined points. The system can instruct the drone on the path it should take, the speed, and the height. The drone can even be instructed to hover for a while at each waypoint.
Suffice it to say that the presence of a GPS module in drones increases their capabilities many fold. If you want a drone that does much more than fly, you want a GPS enabled drone.
Do All Drones Have GPS?
No, not all drones carry GPS modules. There are lower end models that do little more than fly and buzz around and there are also toy grade drones that are great for beginners still trying to get used to having their own drone. None of these have GPS.
How Might GPS Technology in Drones Advance?
As convenient as GPS is, there are several problems that plague it. For example, GPS satellites have a finite lifetime and need to be replaced after a while. Space is a hazardous place, and satellites can easily be damaged by anything from solar flares to incoming meteors.
There are also privacy concerns, because GPS can be used track an individual or a vehicle.
That said, the future remains bright for GPS technology. And this does not apply only for drones. Once you locate an object accurately, the door is opened for many further innovations.
For example, car driving can be made safer if a car has exact knowledge about the location of every other car around it. Same can be said for drones which continue to be a potential threat to other aircraft.
This can go a long way towards making fully autonomous unmanned transportation possible.
Companies that are working hard to make drone deliveries a reality on a large scale are going to have to invest in GPS technology and take it further than it has ever gone before. That’s the only way to guarantee not only the accuracy of their operations, but also the safety of everyone whom their drones bypass.
The possibilities are many, and they all begin with the ability to accurately locate an object anywhere around the world.