C-DRONE GUIDE · 27 JULY 2026
Snow depth mapping by drone: grooming, snowmaking, ski resort prices
For a ski area, snow is both the raw material and one of the biggest cost items: producing a cubic metre of machine-made snow costs energy and water, and grooming redistributes every night a stock no dashboard truly measures. Recent groomers carry depth sensors, but they only see where the machine drives. Drone photogrammetry gives the overview: by comparing a terrain model surveyed in summer with the same survey in winter, you get snow depth at every point of the run, to within a few centimetres. Enough to push snow where it is missing and stop making it where it sits idle. Method, limits and prices observed in 2026.
Published on 27 July 2026, reviewed on 27 July 2026 — regulations in force as of July 2026.
The principle: one summer survey, several winter surveys
Everything rests on the difference between two digital terrain models. In autumn, a photogrammetric flight surveys the bare ground — the ski area's "zero", reusable across seasons as long as the terrain does not change. During the season, each flight captures the snowpack surface; subtraction yields the distributed snow depth, displayed as a colour map run by run: useless drifts, scraped zones, under-covered passages that will close the run first.
The method is scientifically well established: a study by Yves Bühler, Marc Adams, Ruedi Bösch and Andreas Stoffel published in 2016 in The Cryosphere mapped snow depth in alpine terrain by drone and measured accuracy on the order of ten centimetres, while documenting the limits (wind, fresh-snow texture, lighting) (see the study on Google Scholar). In practice, an RTK drone and a few permanent control points (marks on pylons, buildings) keep campaigns consistent.
What it is for: grooming, snowmaking, end of season
Three uses dominate. The grooming plan: the depth map tells groomers where to push surplus snow and which zones to spare — complementing on-board sensors, which it extends to ungroomed areas. Snowmaking control: crossing measured depths with operating thresholds, production is trimmed gun by gun — a direct water and energy cost issue, and an argument in the environmental files of storage reservoirs. End of season: the stock measured in March supports an objective call on sector closing dates, and snowfarming (conserving snow under sawdust) is sized on measured, not estimated, volumes.
The same flight also serves development studies: run reprofiling, a new lift line, preventive avalanche-control zones — alongside the structural monitoring of installations described in our ski lift inspection guide.
Flying in a resort: the real constraints
Winter mountains stack up constraints: ubiquitous cables (lifts, power lines) that shape flight plans, cold that cuts battery endurance, ridge winds, and above all the public: you do not overfly open runs. Flights happen at dawn before opening — when groomers want the information — or over closed sectors. Coordination with the operator works like a worksite: slots, the resort's radio frequencies, stop rules.
Airspace-wise, add mountain restricted areas and parks — our mountains and national parks guide details what can be flown — and weather rules everything: our weather and cancellation guide applies to the letter at altitude. These missions call for a pilot seasoned in alpine flying; make it an explicit selection criterion, alongside RTK equipment.
Honest limits of the method
Photogrammetry on snow has documented pitfalls: uniform fresh snow under overcast skies lacks texture and degrades reconstruction — flights are planned a day or two after a snowfall, or in low-angle light; wooded areas hide the ground; and accuracy stays around ±10 cm: enough to manage a 50 cm to 3 m snowpack, not to measure 5 cm of refreeze. For scientific needs (mass balance, avalanches), drone LiDAR does better under forest cover, at higher cost.
Finally, the depth map is a snapshot: its value comes from repetition — typically three to five campaigns per season at pivotal moments (pre-opening, January, February holidays, mid-March). It is the same differential-monitoring logic we describe for glaciers: you do not monitor an image, you monitor a change.
Prices observed in 2026
Ranges observed in 2026 (excl. VAT), for a ski area equipped with permanent control points:
- Autumn "zero" survey (bare ground, multi-year base): €2,000 to €5,000 depending on area.
- Winter campaign (snow depth maps of a sector of a few dozen hectares): €1,500 to €3,500 per pass.
- Season package (3 to 5 campaigns + groomer-ready deliverables): €5,000 to €15,000 depending on area and frequency.
- Snowfarming or stock volume (one-off measurement of a deposit): €600 to €1,200.
Set that against a season's snowmaking bill: a few percent of optimisation pays for the service. Request a quote stating the run area targeted and the number of campaigns wanted.