What needs to be considered when operating drones in winter?

Flying in winter is not a problem—as long as you take into account that several factors deteriorate at the same time.

Batteries lose performance

Cold temperatures increase internal resistance: Voltage drops sooner, usable capacity decreases, and the critical phase of the discharge curve begins significantly earlier than usual. Expect noticeably shorter flight times and land with a greater reserve than in summer.

What helps: transport batteries in a warm environment and install them only shortly before use, bring them to operating temperature before take-off, and take off promptly after preheating. Many systems preheat the battery themselves—this also consumes capacity, however.

Condensation

The classic mistake: taking a cold drone directly from the operation into a warm vehicle or office. Moisture then condenses on and inside the electronics. It is better to let the drone acclimatise in its case and only open it once the device has reached room temperature.

Icing

At temperatures around freezing, with high humidity or drizzle, ice can form on the propellers. This changes the aerodynamics and weight—quickly and unevenly. Signs include a changed sound and a drone that responds sluggishly. Do not fly in such conditions.

Visibility

Short days, low sun and diffuse light against a snow-covered surface: The actual visual range is often only a fraction of the summer range in winter. Against a grey sky or over snow, a grey drone can disappear surprisingly quickly.

For surveying

Fresh snow has little texture—the photogrammetry lacks common image points, making the results unusable. LiDAR has an advantage here because it does not rely on texture.

And the pilot

Cold fingers make it harder to operate the control sticks, and displays become sluggish in cold temperatures. Gloves that allow precise motor control and a position protected from the wind are not a luxury.