Collecting data safely with a fleet of drones

Welcome to Wageningen Airport. The WUR drone fleet is not limited to making test flights around campus, but it is a frequent flyer abroad too. But whether the WUR drones are flying over the tropical rainforests of French Guiana or along the Dutch coast, the rules are always observed. This includes privacy regulations.

At Action and HEMA, they’re sometimes on sale for less than twenty euros; the NASA one is in a whole different league and has been flying around the red planet since last year, some 470 million kilometres away. Drones come in all shapes and sizes for every purpose imaginable; from toys and photography to scientific research. This is why you can see them more frequently in the airspace around Wageningen.

These Unmanned Aerial Vehicles (or UAVs) are advanced pieces of equipment that literally and figuratively fill the void between satellites in the atmosphere and geosensing systems on the ground. There are currently 15 models in the WUR drone fleet and it is still growing, from relatively small half kilo platforms to 25 kilo ones that can carry up to 8 kilos of cargo — batteries and cameras. The drones are used all over the university for a wide range of research: from coastal monitoring to profiling cows in a field, from studying buttercup blossoms in the Biesbosch to recording soil erosion and helping to optimise the broccoli harvest.

Pioneering in Wageningen

Ten years ago, WUR started the Unmanned Airborne Remote Sensing Facility (UARSF). Remote sensing — acquiring spatial information about the earth’s surface — was not new, of course, but using it in 2012 was definitely still pioneering. “We used drones that we could keep in the air for only 12 minutes. Now, we can easily perform flights of half an hour,” reminisces Lammert Kooistra. Kooistra is associate professor of Remote sensing with drones.

We used to use drones that we could keep in the air for 12 minutes

Technology has not just evolved in terms of motor-power and battery life — cameras are also undergoing revolutionary developments. Kooistra recently attended a successful test flight of a new hyperspectral camera above Unifarm’s experimental fields.

“This camera, which we bought at the beginning of the year, can make very detailed recordings of up to 100 spectral bands per pixel, and it has LiDAR for 3D information. In this way, we can combine two types of data collection so we can measure the same things spatially. We can apply this system to better detect diseases in plants, for example, by measuring whether plant growth is stunted and whether leaf shape is changing. We achieved good results with potato viruses before, but we want to extend this application to orchards and fruit cultivation, among other things. Certain fungal diseases that cause toxic substances in grain that can then also be detected much earlier on.”

A good start is more than half the work

The benefits are clear: these drones are not toys, but serious data collectors. The aforementioned test flight took place just over the on-campus test fields. It took less than 15 minutes, but with an altitude of 30 metres, the drone was able to collect 30 gigabytes of raw data. The altitude of 30 metres does not sound extreme, and the location, just north of Wageningen campus, is not exotic either. Still, many hours of preparation go into those 15 minutes of flight time. For the sake of ensuring safety and privacy as much anything else.


Kooistra: “We do a great deal of flight preparation before every flight and for every area.” We draw up operational plans that describe what we want to do, who will fly and who is responsible. In essence, there is no difference between preparing for a drone flight than for a flight in a Boeing 747. The flight plan is an excellent tool for assessing potential risks, and it is always discussed with the crew. There are at least two people for each flight: a pilot and an observer.”

Secret areas

“The next question is ‘am I allowed to fly there?’ A great many areas are subject to restrictions too. Some are permanent no-fly zones, owing to the presence of military installations, while others have temporary restrictions, for example in breeding season. For example, the area north of the campus is a low-flying zone for military platforms. You cannot fly at certain times of the year, so we need to check in advance. It is also necessary because our equipment is insured on a liability basis. If something goes wrong, the insurer also needs to know how the accident happened.”

In just 15 minutes, the drones could collect 30 gigabytes of raw data

Naturally, all pilots have the right papers and the platforms are certified according to the new European regulations. “We are also in regular contact with the Human Environment and Transport Inspectorate (IL&T), which monitors drone flying in the Netherlands.” The Wageningen drones

“One of the first steps in preparation, if not the very first, is asking permission to fly from the owner of the area. They can be a grower or a farmer, or a nature reserve management organisation or Water Management. After they give permission, the next step is to go and appraise the location. There, we look at who is active in the area and what to consider in terms of security,” says Kooistra.


But what about privacy? What if a WUR drone, as part of its research into how new sand dunes develop, accidentally catches a couple in flagrante delicto? “Most of our cameras do not have enough detail to recognise faces. However, naked bodies are another matter. The images we collect are not shared with third parties. We process the raw footage and check whether people are recognisable or not. If they are, we blur them because we do not want to make that kind of information available. It is really only about the information that can be extracted from the camera recordings.”

Stringent privacy regulations

Drones are not just used at Wageningen for scientific research. Last week, WUR’s facilities department looked into whether drones could be used to make roof management more effective. The hired company made a really detailed recording, on which you can see every pipe and screw, as it were. Kooistra: “That company is obliged to blur out any incidental footage of people walking around the building. They are only allowed to provide information about the objects: not the people. The same rules apply to us.”