Introduction:
When it comes to agricultural drone use there are three main categories that should be considered; Scouting, Mapping and Spraying. Even with just agriculture in mind, the possibilities for drone use are more-or-less endless and a decision on which system to use often comes down to money and time.
Agricultural Drone Mapping:
Agricultural Drone Mapping is where a drone flies a grid pattern over the entire field, going back and forth and taking many pictures of the crop.
It requires:
A drone to fly the mapping flight
A mapping app to control the drone
A phone or tablet to run that app on
A processing/stitching program and…
A computer to run that program on.
Picking the right drone for the job usually depends on the area of land that needs to be covered. Large areas are sometimes suited to fixed wing drones, which are more efficient over bigger fields. In smaller fields however, it’s much better to use quadcopters/multi-rotors, as they are usually cheaper, have much better maneuverability, and are multi-functional i.e. they can be used for filming, general photography, stationary inspection, mapping and scouting, whereas a fixed wing drone can only be used for mapping.
Multispectral drone/camera systems can also be used to create up-to-date maps that can analyse crops using various vegetation health indices, such as NDVI and NDRE. This is data that is usually only provided by satellite, but multispectral drone systems can produce it regardless of cloud cover.
When a mapping flight is complete, those images usually have to be manually taken from the drone and uploaded by the user, to computer software that is either installed locally on a PC or run on a web browser in the cloud, which will then stitch the images and turn them into a single, high-resolution map.
These mapping flights can take quite a long time, depending on the resolution that is required of the final map, and if a high resolution map is indeed required, this in-turn requires the user to have plenty of batteries at their disposal.
They will also have to back up their images and clear out their SD card storage regularly.
Stitching Software:
Stitching Software, as mentioned above, is what is needed after a mapping flight, to process the images into a map.
It comes in many forms as well, and usually requires a high-end PC that can handle point-cloud generation and full orthomosaic stitching. This is before considering the cost involved.
There are exceptions on the processing front, but all stitching options have a price…
For general agricultural mapping, Pix4D Fields is an incredible piece of software, it uses algorithmic stitching rather than true photogrammetry, and does a fantastic job whilst not using much power – the result is a map that can be generated very quickly using even a small laptop, with relatively high-resolution and without an internet connection.
There are some drawbacks however; one is that the map is 2D only, but in an agricultural environment, this has little significance.
The other issue is that a subscription to Pix4D Fields costs about £1,310 per year…
There are other options out there, such as Sentera’s FieldAgent platform, which includes the flight software and viewing software, but which either requires you to install a third program to stitch the images, provided you have a high-end PC or, you can upload them to Sentera’s servers directly, where they will process them for you, at an additional cost per map.
DroneDeploy is a cloud based platform that, similar to FieldAgent, contains both the flight software and the processing platform, but it comes as an all-in-one, albeit expensive subscription cost.
It is, however, not specifically designed for agriculture, and lacks certain functionality over something like Pix4D Fields.
As you can see there are many options for mapping solutions out there – if you are thinking about mapping, don’t hesitate to get in touch with us to find out more, but please consider the next section first…
Drone Scouting:
Drone Scouting, on the other hand, is where you use a drone to image individual points across a field to produce high-resolution photos of certain areas. The images from these flights can be easily uploaded to the cloud, as there are far less of them, meaning less data usage.
This also means that the flights themselves are a lot faster and more efficient, if you have to cover larger areas with limited battery power.
Our software Skippy Scout also has an AI system which analyses each individual image and then sends a PDF report with average AND point specific GAI, Crop Cover %, Weed presence, Insect damage and more.
It also includes visuals that portray how the system predicts that the crop is doing.
There is no need for post-flight processing, as the system automatically uploads the captured images, even while the drone is still flying.
Skippy is an all-inclusive flight, processing and management system that provides only useful, shareable data, and provides it quickly – creating a real-time, actionable picture of the field, that can inform decisions regarding crop management and prescriptions.
Mapping:
Pros:
- High detail
- Maps can be used for many different purposes
- Many options to suit different tasks
- Can create high-resolution, up-to-date multispectral maps, regardless of cloud cover.
Cons:
- Set up is complex
- Can take a long time to map each field
- Cloud variability throughout flight duration must be considered to avoid “patchy” maps
- Data is usually uploaded manually, which can take a long time and be quite complex depending on software options
- For some software such as Pix4DMapper or FieldAgent you need a powerful PC build to be able to locally stitch the maps together
The only alternative to a powerful PC is spending more money - Need a lot of drone batteries to cover multiple large areas in the same day
- Data overload – surplus of useless data as opposed to only useful data
Software and drone systems are a lot more expensive for mapping than scouting (though some drone systems can do both)
Scouting:
Pros:
- Very fast and efficient way of covering crops
- Less battery intensive than full scale mapping
- Gives precise data on specific points around the field rather than broad scale data generation which means:
- Less processing time & less useless data generation
- Can very easily be processed by AI models due to the high detail sample images
- Low altitude flights which are not as affected by wind conditions compared to mapping.
- Don’t need a PC at all to handle the data processing
- Low cost of entry
- Software is uncomplicated
Cons:
- Don’t get complete coverage
- Images are taken in RGB format only i.e. multispectral systems are not yet supported.
Multispectral Mapping:
Many different drones can be used for mapping and scouting. Mapping, though it can be done using some standard drones, can also be accomplished using higher-end drones with cutting-edge multispectral cameras, to generate high-quality, high-resolution, multispectral data.
The entry level for more specialist drones for mapping, would be models like the DJI Phantom 4 Multispectral, which captures imagery in 5 different spectral bands, at low-resolution, and the Phantom 4 RTK which captures in high-resolution RGB (standard) – both of these drones use RTK (Real Time Kinematic) positioning to be accurate to the centimetre.
There are also much more expensive, industry level drones such as the DJI M300, which are capable of doing almost anything, but which are usually overkill for this kind of purpose.
However, when it comes to multispectral payload options, Sentera takes the crown for the highest quality hardware.
Their multispectral payload options are the best of the best, and are actually relatively affordable compared to their competitors.
Scouting on the other hand is often done with standard DJI camera drones, which makes it very affordable and easy for most users. Skippy Scout is also a great balance between being very affordable and very easy to use, especially compared to mapping software, which is either expensive or complicated, or both!
Currently Skippy is only compatible with off-the-shelf DJI drones such as the Mavic 2, Mavic air 2, Mavic mini 1 and the Phantom 4 drones, but with an aim to make as many multirotor drones compatible with the software as possible.
But what is the best drone for agricultural use, in our opinion?
*Drum Roll*…
The best drone for agricultural use would be the DJI Air 2. This drone is very good value for money (around £750) and has great features including being able to take 48 megapixel photos and film in 4K!
It also has a much longer flight time (around 30 minutes depending on wind conditions and temperature) when compared to the other multirotor drones in this list and it’s very portable and small, like its other “Mavic” counterparts – with the propellers and arms folding alongside the drone for easy transport and storage. It is compatible with Skippy Scout but is also compatible with GSpro for full mapping flights.
Drone spraying as a side note:
Another use for drones in agriculture is spraying. Pesticide application from drones is currently not legal in the UK however it is used all over the world and we hope to see it adopted here soon.
There are currently two main DJI drones on the market for spraying and they are the T10 and the T30. The T10 has a 10 litre tank and the T30 has a 30 litre tank and they spray roughly 10-16 hectares per hour. Currently the only thing holding back the use of these spraying drones is the legislation around chemical use from an aircraft. Fitted with RTK precision these systems are perfect for dealing with hard to reach problem areas that could be caused by rough terrain or wet ground. The future is bright for drone spraying however with the DJI Phantom 4 M and Skippy Scout being able to send spraying maps directly to the Spraying drones allowing for targeted spraying.
There are also a few other companies who make spraying drones however DJI are currently leading the market.
