Stephanie Sutherland, director of Falkirk-based Goshawk Forest Mapping, breaks down how to get started with drone technology and how you can utilise it in your business.

DRONES have been making a major buzz in forestry for two or three years now. They can give us cost-effective access to some extremely useful data and make safe some operations that are normally dangerous, like windblow surveys.

Put simply, they let us arrive on site in our cars, get out and see the forest from a bird’s-eye view – and integrating drones into your business can be as easy as you want it to be. Several companies now offer drone services to the forestry industry. A simple map should allow you to get a quote and you shouldn’t need to accompany them to the forest.

Do make sure they have the necessary permission from the Civil Aviation Authority (CAA) to fly commercial operations as this is a legal requirement. Your drone operator should be able to supply you with their Permit for Commercial Operation (PfCO).

Alternatively, you can get your own drone (starting at around £1,000) and PfCO (around £600) and start taking imagery for your business yourself. Please be aware this route will require a lot of your time.

Forestry Journal: An aerial image of a restock site and mature forest. An aerial image of a restock site and mature forest.

Either way, we have a few options for getting drone imagery of the forest. The simplest would be to take video and pictures while you’re flying around above the trees. This can provide a good update of the general health and wellbeing of your crop or the progress of a harvesting operation.

Next is photogrammetry, which takes many pictures looking straight down at the ground. Stitched together they make a georeferenced orthomosaic you can load into GIS software for collecting spatial data.

If you want a more technical check on crop health, you might want to think about multispectral imagery. You can get a multispectral sensor for around £5,000.

One thing that always comes up in conversation when I say I fly drones to map forests is LIDAR. LIDAR is capable of giving us a measurable 3D picture of the forest, using lasers to make measurements of the environment and collecting some data from below tree canopy level. This allows us to calculate a good approximation of crop volume. It costs £60,000 for a sensor capable of taking enough data to measure a forest and you’ll need to invest in some mega drone hardware to carry this precious cargo.

Forestry Journal: An example of a windblow survey.An example of a windblow survey.

There are rules about where you can fly. Special permission will be needed near airports and crowds and you can’t fly within 50 m of another person, vehicle, structure or vessel without the owner’s permission. More information is at

One rule in particular that limits our ability to collect mapping data in forestry is known as ‘visual line of sight’ (VLOS). You can fly your drone no more than 120 m above ground level (AGL) and 500 m away from yourself horizontally. You must be able to see your drone with no assistance from visual equipment.

All these rules mean getting mapping data of a vertically blessed crop such as trees can be a problem as, in a mature forest, the drone won’t get far away before it disappears from sight.

With good planning and some hiking, a lot of forests can be mapped. Your drone operator should be able to give you a good steer as to whether the forest can be mapped before you say yes to a quote. If they can’t or won’t, or don’t seem too fussed about potential loss of line of sight, then move on to a different company.

Depending on the site conditions, one drone can survey 250+ ha of mature forest or 350+ ha of ground prep in one day. Drones are part of the future of forestry. Is your company ready to make the most of them?

For more information, contact Stephanie Sutherland on 07388 038 512, email or visit