So, you’ve got your surveying drone. Perhaps it’s sitting on your desk right now, staring at you, or perhaps someone’s taken it out for a quick test drive. But if you’re surveying, the UAV itself is only one half of the picture. Now, you need a payload.
No doubt, you’ve already put some thought into your payload since you’re using your drone for surveying. So it’s likely that you know you only really have two options: you can either buy an all-in-one payload, or you can build your own payload (either yourself or through a professional company). In this blog, I want to discuss those different approaches – and explain why, if you can put in the energy to build your own payload, you can end up with a much more effective drone.
The key differences between a pre-built payload and a custom payload
They’re pretty simple really. A pre-built payload gives you no flexibility over what is included, while a custom payload does.
A custom payload is obviously therefore more flexible. In fairness, the number of pre-built configurations are growing all the time – but there are still reasons to consider a custom payload.
Here we outline our top three reasons why choosing to build a custom payload may be the way to go…
Reason 1: You’re still limited on choice
Even though more and more configurations of payloads are being offered by companies, you are still restricted to whatever range of sensors a company has decided to include in the payload. So, if there
isn’t a payload that meets your specific needs, you’ll have to compromise. That might lead to one or
more of the following consequences:
- You might have sensors that are a lower spec than you wanted, compromising the quality of your final outputs.
- You might have sensors that are a higher spec than you wanted, which represents an unnecessary expense.
- You might have sensors you don’t need at all, adding unnecessary complexity.
- You may have a payload that weighs more than you want, limiting your range and/or battery life.
Reason 2: It’s hard to customise in the future
pre-built payload might be great for your needs right now, but what about in the future? LiDAR and photogrammetry technology are improving all the time. Most pre-built payloads are sealed units, meaning that it’s almost impossible to remove individual components. So, if you want to upgrade your LiDAR, or add a better camera, or add in a better INS, you have to buy a whole new payload.
Contrast that with a payload you build yourself, where you can easily swap out components when it’s time to upgrade (or if any of them should fail). You’ll be able to evolve your drone in line with your business needs much more easily (and cost-effectively, which leads me on to my next point…)
Reason 3: you’ll always be paying over the odds
Part of the cost of a pre-built payload will always be the time and expertise required to assemble it for you. With a custom build, that portion of the cost can be put towards a better-quality sensor, or saved.
“An ‘off-the-shelf’ LiDAR payload, whilst great for start-ups, can sometimes be restrictive. Once an investment in a payload is made, it can be very difficult to upgrade the sensors if, and when customer buying habits or projects change. It’s important to establish, early on in the purchasing process whether in the future will be a need to use better navigation or LiDAR sensors”
Jonathan Deacon, Product Engineer, OxTS
Thinking back to the point about swapping out sensors, if you need to upgrade or replace a sensor, a pre-built payload may need replacing in its entirety, which will likely be vastly more expensive than replacing just one component. With a custom payload, you may even be able to resell on components you’re replacing with upgraded versions, helping recoup your investment.
The heart of any good payload: a high-quality INS
Hopefully this article has given you some food for thought when it comes to your UAV’s payload. A pre-built payload might be exactly right for you, and if so then that’s great news – but if you’re looking for the most flexible, powerful and ultimately cost-effective solution, a custom payload is the way forward.
To close off the topic, if you do decide to build your own surveying payload then don’t forget to include a powerful inertial navigation system, or INS.
An INS combines GNSS signals (like GPS) and data from an IMU (a collection of highly sensitive accelerometers and gyroscopes) to give very accurate position, pitch, roll and heading information. The INS is what enables you to georeference your data (unless you use GCPs, though as we’ve pointed out in other blogs GCPs have some drawbacks), and is therefore a vital part of your payload.
At OxTS, we’ve been making INS devices for a quarter of a century. We’re passionate about giving aerial surveyors an INS that gives them the best possible SWaP (size, weight and power) ratios, without breaking the bank. Our xNAV650 INS provides centimetre-level accuracy, can maintain position accuracy even in forests and cities where GNSS coverage is poor, is incredibly easy to integrate with other sensors – and weighs just 130 g. If you’re building your own custom payload, it’s an ideal inclusion to give you the very best data for your project.