How Drones Can Hover (Explained for Beginners)

If we flash back to 10 years ago, a drone with good hovering capabilities was almost nonexistent. 

But things slowly started to change, and just as in computing technology, drones show one of the highest technological growth rates.

With such technologies and characteristics enclosed in such small UAVs, making us wonder how these drones can hover and do it so steadily.

In this article, I will explain everything you need to know about the hovering capabilities of a drone.

Can drones hover in one spot? #

Yes. But you probably already know that. 

A drone is capable of hovering relatively stably in a single spot with a minimal margin of error (+/- 0.2 meters, on average)

With today’s latest technology packed in advanced drones such as the DJI Mini 4 Pro or Mavic 3 Pro, there’s no surprise that the hovering stability is nearly flawless. 

If we had to do this manually, it would be nearly impossible to beat such computers and sensors for better hovering stability. 

This is one of the first traits to characterize a standard GPS drone: It can hover.

Outside of standard drones, there’s no other device or machinery that has the need to hover or that even can hover like a drone. I keep trying to think of one, but drones are unique in using this automated technology. 

When we refer to the technology behind a hovering drone, at first, it doesn’t appear to be that complex.

Some vision sensors are for low-level hovering, the GPS module is for accurate hovering at higher altitudes, and the motors receive the command from the flight controller to exercise the same amount or fluctuating thrust while the drone is (or should be) in perfect balance. 

Each motor will further compensate to keep the drone stable and hovering in a single place, but it has to take its input from somewhere, so that’s where the technology comes in.

**» MORE: **Can Drones Hover in One Spot? (Explained for Beginners)

Why do drones hover in one spot? #

Answer: For increased safety and convenience.

Hovering capability is one of the features you depend upon if you want to take the best videos or photographs with a drone.

With a drone with excellent hovering stability and a 3-axis gimbal, the videos can look extremely smooth, and you can even take long exposure photographs with a drone.

Even if the drone has a slight margin of error in the hovering stability (and believe me, no drone is capable of flying perfectly still), the 3-axis gimbal will compensate by locking the view onto a direction, giving us the flawless frame to capture what you need.

And even when you do automated shots, such as QuickShots or Waypoints, the drone’s intelligent system will control the direction, but the same hovering stability will keep the drone flying in a nearly perfect linear path.

This is the utmost convenience.

Now, if your drone gets out of range or suddenly loses signal to the controller, here we get to the safety reasons behind hovering.

If the drone wasn’t able to stop in place and calculate what to do next (e.g., auto-initialize the return-to-home), we could be looking at a possible fly-away or crash.

Even with the DJI FPV and Avata, which are two FPV drones released by DJI, you can be thankful for the standard type of hovering, which is more than beneficial if the drone gets out of range or you switch flight modes.

A cheaper drone with poor hovering capabilities (that will often drift) is more dangerous to fly, especially if you have obstacles around. And yes, more expensive drones do hover better than cheaper or toy drones.

**» MORE: **5 Essential Safety Rules You Need to Consider When Filming with a Drone

How a drone can hover #

Now, how does this actually happen? How does a drone hover from an engineer’s point of view?

The flight controller and downward vision sensors #

It’s no surprise that a drone has a computing system that calculates real-time actions sent from the pilot via the remote controller, rectifies flight errors, and improves hovering stability.

But the computing system can’t do that by itself. It needs to have some sensors to help, so this leads us to the downward vision, other types of sensors, and the GPS location module.

Now, the vision sensors are located below a drone. There can be one, two, or three, in pairs or individually. They can be infrared or vision-based, ultrasound or even laser in some aircraft.

The main reason for these sensors is to translate what’s below the drone (e.g., ground) into data and keep it in place hovering. 

Have you ever seen a drone landing? It’s so smooth and accurate, and we can mostly thank the doward vision technology for helping with that. 

With even the slightest drift-off from the drone position when hovering at a lower altitude or landing, the computing system will try to adjust in real time.

But there is a lot of firmware work behind these drones and improvements with many firmware updates that help with these real-time calculations and overall drone stability. 

So, with drone manufacturers like DJI, where the company puts a lot of effort into improving their drones via firmware, we can expect possibly the best hovering results.

But generally, a drone won’t hover only with the downward vision sensors. And here’s why.

These vision sensors usually have a limited range they can read, and that is about 10 meters, more or less, depending on the drone.

So, if your drone is at 50m altitude, these sensors are more than likely useless at that point.

But if you’re flying a drone indoors, sensors are how it can hover, because indoors you don’t get a GPS lock, which is the second module to help with the hovering stability of a drone.

The gyroscopes and IMU also play a crucial role in drone orientation and hovering stability.

When the gyroscope feels a slight inclination of the drone, it knows it is starting to drift away if no input has been sensed. So, with the computing system and other sensors, it realizes it is drifting off, so it attempts to stabilize it back again. All this within milliseconds.

Now, the inertial measurement unit (IMU) keeps collecting data from the magnetometers and accelerometers in real time to send to the flight controller for a decision on stabilizing the drone.

So, although we have the vision system and GPS module, there’s a lot of computing power behind a drone’s internal system, which has sensors for the drone to make autonomous decisions and hover in the same place.

If these sensors were not present in a drone, the drone could never hover and remain in one place; it would drift off and even crash. 

**» MORE: **What Are Downward Vision Sensors in Drones? (Explained for Beginners)

GPS location device #

Nowadays, almost every drone, or at least every decent drone, has a GPS module, a crucial part of a standard drone.

With this module active and locked onto enough satellites, the drone can know its accurate position, use the return to home, know how to come back when it gets out of range, and land accurately, but most importantly, as per our topic subject, to hover.

These GPS modules have advanced quite a lot during the past few years. And yes, a drone could rely only on a GPS module to hover because it can be located within a radius of less than a meter in real time.

The more advanced GPS modules can pinpoint the drone’s location even to a tenth of a meter. And no, I’m not exaggerating. 

Now, the drone can use its own GPS module to keep it in place and hover and readjust its location if there are drift-offs. 

This, together with the downward vision and other sensors, makes the best combination in terms of making a drone hover. 

Have you ever seen a drone hovering inside? Sometimes, it drifts off slightly because it is using only the downward sensors and the data from IMU.

And believe me, the same thing happens if the drone is at a higher altitude where only the GPS module is helping it hover. Maybe you don’t see it because it’s too far up, but there could be slight drifts and a margin of error.

So, when taking off and landing, all these sensors and modules are fully active; that’s why, once more, a drone can land so smoothly.

**» MORE: **DJI Drones: You Need This Many GPS Satellites to Fly

Drone hovering vs. wind #

A drone’s wind stability is the next big thing. 

About all DJI and non-DJI drones are rated on how well they can fly in higher winds. This is not really related to the motor’s power to face strong winds but the drone’s overall stability and how well it can hover and fly.

For instance, if the wind is blowing from the left, the gyroscope knows that because it feels an inclination, and it sends a signal for the right motors to exercise extra force to keep the drone hovering stable (when hovering). 

All these fluctuations are calculated in real-time, and with the help of downward vision sensors, gyroscopes, magnetometers, accelerometers, and the GPS module of a drone, it can remain stable, hovering within limits. 

But then, if hovering in higher winds, the drone will be wobbly, something like a boat facing some waves. However, with the help of 3-axis gimbals, the resultant footage is as smooth as flying in no-wind conditions.

The drone’s aerodynamics also contribute to how well it can hover in strong winds. The air current has to circumvent the friction as much as possible to reduce how much it impacts the drone’s stability.

Looking at a drone’s wind resistance, expect to be able to fly in much stronger winds than advertised. 

Even if the recommended manufacturer values are not the wind speed limit, keep in mind that you probably won’t be covered by warranty if you manage to crash your drone while flying in higher winds than advertised. (e.g., Level 5 Wind Resistance with max winds of 10.7 m/s).

**» MORE: **Can a Drone Fly in Strong Winds? (With Flight Tips)

Can an FPV drone hover? #

Taking a step further from standard drones, we have FPV drones equipped with few-to-no sensors.

An FPV drone flying in acro mode cannot hover at all. It has no active gyroscopes or leveling systems to help with hovering. And that’s the entire point behind an FPV drone – to fly it in acro (manual mode) and have total control over it.

If those sensors are active and decide to stabilize your drone, you won’t be able to do any acro freestyle.

Hovering an FPV drone is another story. You will have to do it manually.

So, controlling and micro-adjusting an FPV drone to remain in the same spot is quite a problematic acro movement and needs a lot of skill and practice to perfect it.

Still, it cannot compare by far with the computerized hovering system of a GPS drone, which is all automated.

When hovering with an FPV drone, you have to take into calculation the wind and environment in your hover. 

Even the slightest mistake can destabilize the drone, so you must adjust it as perfectly as possible, or you’ll quickly lose the hovering position.

**» MORE: **FPV Drones vs. Regular Drones (Explained for Beginners)