Can drones fly without GPS?

Can drones fly without GPS?

Trying out a new experience of flying a drone in a cave may be quite dispiriting for a beginner. The GPS installed in many modern drones does not work in this environment. Do these render the machine useless in the surrounding? Of course not. Drones can fly without GPS. It only requires more expertise and a good knowledge of each mode. First, let’s see how GPS functions.

What is GPS, and how does it work in drones?

Global positioning system (GPS) is a network of about 30 navigational satellites set at a given altitude. Each of the satellites sends its positional information and current time after specific durations. The GPS module installed in the drone picks the signals from the spacecraft and calculates the in-between distance. Out of the 30 satellites, only three are required to determine the exact position of the drone.

The principle of calculation of drone position using three satellites is known as trilateration. It states that three circles (distance from each satellite) with different centers can have only one crossing point, which is the drone position.

Modes of flight for a drone?

There are four modes of flight for drones: loiter, altitude hold, stabilize, and manual.

Loiter mode is the most commonly used and recommended for beginners since it employs GPS technology. In this mode, every movement due to external forces is automatically corrected. The drone holds a position on all the four axles and only changes direction upon receiving a signal from the transmitter.

Besides loiter, the other modes do not require GPS to fly the machine. Let’s explore how they work.

Altitude hold mode

The drone uses a barometer to maintain its height in the sky automatically. Its difference with the GPS mode is that change in position due to an external factor like the wind needs the controller’s input to correct. Again the pilot must actively control the position in roll, yaw, and pitch axles.

Stabilize mode

The drone does not hold any position, and the pilot must actively control the position in all the four axles. However, when you take your hands off the control stick after making any control movement, the drone automatically zones out roll and pitch, thereby landing on a horizontal position.

Manual mode

This is the last and most challenging to use, therefore, left for the masters. In this case, the device does nothing without a pilot’s input. Upon making a control movement on the yaw axle, the aircraft maintains that positions and keeps moving until a reverse command is given. Since there is neither horizontal leveling, nor altitude/position hold, this mode is mainly used for gaming and acrobatics.

For beginners, you are advised to first acquaint yourself with the GPS mode before trying out the other patterns. Then slowly, you can start with more straightforward non-GPS modes such as ATTI and move upwards after mastering each level. You must, however, be aware of how the drone reacts in each mode before practicing.

Remember, certain functions such as ‘coming home’ can only operate in the loiter mode.

Tips for flying a drone without GPS?

Flying a drone without GPS may be more fun than using GPS only that it is more demanding. The aircraft is not stable in the air and requires partial or total active control by the pilot. A learner can find this quite troublesome, but with more practice, the art is mastered.

1. Have a large and open flying area. You may fumble with the control buttons one or more times, causing the drone to crash. It is, therefore, essential to be in a vast-open area to prevent any damages. Always stand behind the device such that you face the same direction as the drone.
2. Before you can comfortably operate the drone in non-GPS modes, use the loiter mode first to fly the machine to a safe altitude. After this, you can now switch to altitude hold mode and prepare to control the aircraft actively.
3. For the safety of your drone, you can always turn back to hover(GPS) mode if you experience any trouble during the flight.

Is it possible to use autopilot without GPS?

Unfortunately, this function on the controller requires an up to date GPS to operate.  It works by calculating the distance between the actual drone position and the desired place and setting the signal to the drone, thus automatically correcting position.

Can I use IOC without GPS?

Intelligent orientation control (IOC) is an essential tool that helps the pilot take charge of various adverse conditions. There are three modes of IOC which differently change the method of controlling two axles (pitch and roll)

Normal flying-In this IOC mode, the drone moves forward with the forward positioning of this control stick on the pitch axle. The direction the drone face does not affect the side of movement whatsoever.

Course lock- The drone automatically saves the nose direction after being turned on. Any change in direction, later on, may not be useful as a forward signal will produce movement in the nose direction of the start position. As a pilot, you must not change your position; otherwise, you may lose control of the flight.

Home lock Flying-Home position of the drone is the most vital in this mode. A forward control signal causes the drone to move away from the home point, while a circular movement around the home point is the result of a right or left signal.

The normal flying mode does not require GPS to function while the course lock and home lock cannot work without the GPS.

Conclusion

Drones can be flown without GPS though it is quite tricky and requires some experience. The different non-GPS modes of flight must be mastered to fly the drone flawlessly.

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