We often think of drones as a powerful data collection tool. In reality, however, the drone is just the vehicle. Each drone flies with a sensor, and it’s the sensor that does the data collection. You can think of it as your drone’s eyes. Each type of sensor is a new pair of eyes — an opportunity to see the world from a different perspective.
Whether you’re just starting your drone business or looking to take your operations to new heights, it’s important to understand the available tools and how to best use them to drive operational success.
Here, we’ll talk about the five main sensors currently being utilized by drone companies. We’ll look at how they work and why they’re important. We’ll also throw in a few tips to help you select the sensor that best fits your needs.
The RGB Sensor
All drones have an RGB sensor. This is just a fancy term for the standard camera that consumer drones are equipped with. Still, these cameras have wide-ranging industry applications. Ultimately, choosing the right camera can make a substantial difference in your operations.
When evaluating which RGB sensor is right for your business, consider what level of resolution would be appropriate for your customer base. A customer may be looking for an aerial map of their operations. Ask yourself how detailed a map your customer might need. For instance, agriculture companies may want plant counts of their fields, which means they’ll need high resolution maps that clearly capture the outline of individual crops. For applications like this, you’d want to use drones that are market leaders in camera resolution, such as DJI’s Phantom 4 Pro and the Mavic 2 Pro.
In other cases, too high a resolution might be overkill so a less expensive alternative such as the DJI Mavic Mini may suffice.
You might also be interested in using your drones to capture videos. Practically all leading drones in the market have video capability. As with cameras, the difference is mainly in the resolution. For example, he Phantom 4 Pro and the Mavic 2 Pro both capture high definition 4K video, while the Mavic Mini only has a 2.7K video resolution.
The Thermal Sensor
With the thermal sensor, your drone can now see the world with a new set of eyes. Instead of capturing what an ordinary camera sees, the thermal sensor measures infrared radiation. The hotter the object, the greater the infrared radiation. This means that the sensor is useful in locating temperature anomalies—areas that are either too hot or too cold.
There are several industry applications for thermal sensors. In search and rescue, drones with thermal sensors have been deployed to look for missing people. In the energy sector, companies have been able to detect overheating power lines and equipment through the periodic collection of thermal imagery.
The thermal market is generally dominated by two options: the DJI Zenmuse XT and the FLIR Duo Pro R. The sensor specifications of both units are practically the same. Where they differ is in weight and compatibility.
The Zenmuse, as it is a DJI product, is compatible with the company’s Matrice and Inspire lineup. It’s also the lighter option at 270g. On the other hand, the FLIR sensor can only be flown with the DJI Matrice 600 and it’s roughly 50g heavier than the Zenmuse.
The Multispectral Sensor
While the thermal sensor only collects infrared light, multispectral sensors are able to detect three to five different wavelengths or bands of light. This makes it an invaluable tool when trying to inspect objects or areas for features that might not be visible to the naked eye.
One of the classic use cases for the multispectral sensor is plant health assessment. A plant’s absorption and reflection of certain wavelengths of light is indicative of their health. Healthy plants are able to strongly reflect near-infrared radiation while those that are deteriorating lose this ability. This is why multispectral sensors typically have a near-infrared channel that captures this specific wavelength
There are two considerations for the selection of a multispectral sensor: resolution and the number of bands. The question of resolution is simpler to consider. As with the RGB sensor, this depends on how much detail your customer will need from the imagery. DJI offers two multispectral sensors: the DJI Zenmuse X4S RGNIR and DJI Zenmuse X5S RGNIR.
The X4S has a 12.4MP resolution while the X5S has a 20MP resolution so the latter is better for projects that require high-resolution imagery. Both DJI sensors only capture three bands: red, green, and near-infrared. This is typically sufficient for many applications but more complex use cases often require more bands.
Enter the MicaSense RedEdge-MX. Built specifically for advanced multispectral applications, the RedEdge captures blue and red-edge in addition to the standard red, green, and near-infrared. The 20MP resolution of the RedEdge also makes it a good choice for projects that need high-resolution imagery.
The Hyperspectral Sensor
Sometimes, even the added bands of the multispectral sensors aren’t enough. For especially complex projects, the hyperspectral sensor is deployed. Instead of just three to five bands, hyperspectral sensors capture light in hundreds of bands.
Think of this sensor as a scalpel, finely dissecting the subtle traits of different objects and scenes. Given the level of detail that it captures, the sensor is usually used in the early detection of crop diseases and the identification of small oil pipelines leaks.
Corning has developed a line of hyperspectral sensors compatible with drones. They offer two models, the 410 SHARK and the 425 SHARK, which differ in the range of wavelengths that they capture. The former covers 400nm to 1000nm while the latter gets up to 2500nm. Headwall provides a wider array of options with their most basic being their Hyperspec UV-VIS that only collects 250nm to 500nm. At the other end of the spectrum, their NanoHyperspec is the premium option and captures light with wavelengths ranging from 400nm to 1000nm.
While hyperspectral sensors can definitely add value to your business, this should be weighed against their cost. Because they use sophisticated technology, they are priced much higher than multispectral sensors. You should also have remote sensing experts on your team to deftly handle a hyperspectral sensor’s data.
The LiDAR Sensor
Light Detection and Ranging (LiDAR) sensors are quite different from the other four. Instead of simply capturing imagery, LiDAR shoots a beam of light and detects how far it goes before it bounces back to the sensor. The result is a set of points, called a point cloud, that gives the elevation of the features of an area.
The ability to capture the elevation profile of a scene makes LiDAR valuable to various industries, and the sensor is considered to be the standard when it comes to accurate 3D modeling. Given this, it can be used in agriculture to measure plant height, in mining to recreate pits and stockpiles for volume computation, and even in construction for regular monitoring.
One of the first LiDAR sensors built for the commercial drone industry was Velodyne’s Puck. It continues to be a market leader as it is able to generate point clouds at an accuracy of ±3cm. Other options include DJI’s Livox Mid and RIEGL’s miniVUX-1UAV. Compared to the Velodyne Puck, the DJI product has a slightly higher accuracy at ±2cm, but RIEGL’s is significantly better at ±10-15mm.
Where do I Go from here?
Knowing about the sensors is the first step — understanding how you’ll use them for your business is much more valuable. There’s a lot to consider, but here are three questions you can ask yourself to help you choose the right sensor:
- Who is my customer? Understand who you want to reach out to. Their use cases will help narrow down your choice of sensors.
- What questions do I want to answer? Choosing between sensors is about understanding which one efficiently solves the problem, especially when considering the varying costs.
- What is the sensor compatible with? Some sensors have limited compatibility. Make sure that you choose one that you can seamlessly attach to your drone.
Having the right tools steers your drone business towards the path to success. To keep your business safe and secure, however, you need to keep it protected. If you have any questions around getting your operations covered, reach out to us at info@DroneInsurance.com. You can also explore our options by creating a free account on our website.