Harnessing the Power of Drone Tethers

by coptrz on June 7, 2017

Harnessing the Power of Drone Tethers (including 5 things you always wanted to know, but were afraid to ask!)

As soon as we applauded the brilliance of human engineering capabilities for bringing drones into the mainstream, we decided we wanted more! Great, you’ve got a drone with a camera, but what about 4K video? Yeah, you might have designed a drone capable of carrying a 6KG payload, but we want to mount a LiDAR scanner and an HD camera. With high levels of adoption in the commercial world, UAV users are forcing manufacturers to push the boundaries of drone technology. Here we discuss drone tethers – one of the most important innovations in the UAV world.

One of the biggest limitations of drones to date has been the inability to fly for extended durations. Our recent survey of drone users highlighted flight time as the second most important consideration after camera quality, and given the average flight time of a DJ drone standing at 40 minutes, the limitations can cost a business dearly in terms of time and money.

Introducing…….Tethers

Drone tethers aren’t merely a safety precaution to ensure your drone doesn’t go wayward, they are an alternative power source to enable continuous flight without changing batteries.

Tether stations are quickly becoming an essential piece of equipment for commercial drone operators and although some cost up to 10 times more than the UAV itself, they are worth every penny.

Drone batteries can last between 30-45 minutes depending on the model and payload weight being carried. The DJI Matrice 600 is one of the most robust drones on the market, with one of the largest payload limits (6kg), yet when at maximum payload capacity, the flight time goes from 35 minutes down to around 16. Even if you happen to have another ten batteries charged, you still have to return the drone home each time they run low, meaning that 180 minutes of footage or data will potentially take hours to collect. If you are using drones to save time, or you are a professional drone services company, that time spent changing batteries costs you money.

Drone tethers use mains electricity (or a generator for field work) to power your drone via a thin and very smart cable. The cables are reinforced to withstand weather and traction and also have the ability to transfer data safely and securely. You don’t even need to modify your drone; most tethers come with a component which replaces the standard battery pack which can then be removed as and when needed.

Safe and Secure

Tether stations don’t only offer the ability to fly for extended periods but also improve safety on site. Some of the most common safety concerns are “What happens if the drone’s batteries fail?” or “What happens if my drone loses signal during flight?” The most common result? The UAV falls out of the sky. This is one of the reasons why it’s not permitted to fly over crowds and in many open public spaces. Using a tethered drone is safer thanks to the additional flight modules which regulate both the power and the flight. If there’s a power out, or problem with the generator, the drone is sent a signal which returns it to home, with an additional two minutes of flight time stored in the module to allow for a safe landing. The tether also allows the drone to be physically returned to base, without having to rely on the onboard navigation system, so that in any eventuality, you drone is returned safely to home.

Elistair | Ligh-T & Inspire 1 from Elistair on Vimeo.

Data storage and transfer are also more secure using a tethered drone thanks to the multi-purpose functionality of most tether cables. Securely wrapped inside the micro-filament wire is an ethernet cable which is capable of streaming data and live footage from the drone.

Applications for Drone Tethers:

Drone tethers remove the restrictions placed on operators by the limited flight time available through a standard battery. For those needing to survey large or complex areas, it’s hugely frustrating to get so far and have to stop to swap a battery out. Using a tether means that a full survey can be carried out in one fell swoop. For those operating a commercial services business, this means that data is delivered more quickly to customers and more jobs can be completed in a shorter space of time.

Drone tethers aren’t just good for carrying out extended surveys, they are also invaluable in situations where any downtime can have serious repercussions. Tether stations are starting to see more use in the emergency services sector, where the ability to fly continuously and live stream data makes the world of difference. First responders can make sure that situations developing on the ground can be monitored, continuously. Emergency services can be assured of non-stop communications, even if telecommunications channels are down by using a tethered drone to boost communications signals. Crowds can be monitored remotely, from the clearest perspective, to either identify risks or monitor safety. The ability to fly without any downtime, potentially for days at a time, gives operators the ability to maintain a safe and secure environment.

Another perfect application for drone tethers is in providing assistance for firefighters. When a fire takes hold, fire services need to be able to monitor the spread of the blaze and one of the most effective and safest positions to do this from is above. Whether it’s a wildfire or building fire, using a tether station allows emergency responders to monitor the spread continuously, enabling them to locate hot points and prioritise rescue efforts.

Sample | Aerial Support for Firefighting from Elistair on Vimeo.

In a slightly happier place, drone tethers are also seeing widespread use in the broadcasting sector, with many camera crews coving sporting events or live music events preferring to be tied down. It’s not just the ability to fly for the duration of the event, (although you wouldn’t want to miss seeing who crossed the finishing line first because the camera drone was having his batteries changed). It’s also the benefit of streaming high-quality live data to the masses.

5 Things About Drone Tethers You Always Wanted to Know…

How are drone tethers powered?

Drone tethers are essentially large power conductors which can be powered by mains electricity or a generator where mains isn’t available.

How long can you fly?

When connected to a tether, your drone can fly for as long as your ground station has power, so usually for an unlimited time. If you are using mains power and there is a power cut, there is a reserve power module where your battery would usually sit, allowing you to return the drone home safe and sound.

How much do they cost?

Most drone tethers cost in the region of £10,000 which may sound like a lot but when you consider the downtime spent changing batteries, it’s actually a small price to pay. Imagine you need 4 hours of data or need to cover several hundred hectares of land – if you have to land every 20 minutes and the return of the drone and battery swap takes 10 minutes – you will have two additional hours of downtime. Simply put, a tether means that you can fit more jobs into the day.

Can I just leave a tether outside connected to my drone and go off and do something else?

Although tethered drones are capable of flying continuously and remotely streaming data, it’s not advisable to leave the drone unattended for long periods of time i.e days. You would want to periodically check that the drone is structurally sound after periods of bad weather or high winds and also make sure that your positioning is correct for the job you are doing. That said, yes, you can be sure that your drone is safe and secure when attached to a tether.

How high can I fly with a tether?

Most tethers can reach a height of 100m which is plenty high enough fro most applications.

COPTRZ offer several different drone tethers compatible with drones such as the DJI Inspire, Aerialtronics Zenith and the new DJI Matrice 200, including tethers from Elistair. You can read a handy set of FAQs on their website.

Hopefully we have done enough to convince you of the additional power you can harness using drone tethers (!) Simply put they can save you time and money and be absolutely critical when it comes to using your drone for continual surveillance.

Already sold on the idea? Why not speak with our technical experts to find out whether tethers are compatible with your drone set up?