Mapping snow depth and layers on steep alpine terrain with drone GPR

The challenge

Traditional snowpack checks mean digging a pit and running stability tests. People have to stand on avalanche-prone slopes, the work is slow and costly, and it covers only small spots. GEORESEARCH, a non-profit institute focused on alpine regions, wanted a safer way to see inside the snowpack over larger areas.

The solution

The STRATIFY project, a partnership between GEORESEARCH and LO.LA Peak Solutions GmbH funded by the FFG, used SPH Engineering's Zond Aero 1000 "NG" GPR integrated system. A DJI M300 flew the radar along a pre-defined grid at a steady 1 m/s. A LiDAR altimeter held the drone 5 m above the snow surface.

For reference, the team probed snow depth at 23 points and dug three detailed snow pits, recording density, temperature, grain form and size, hardness, wetness and stability.

The results

• An algorithm developed in the study picked out layer boundaries automatically, giving snow depth and stratigraphy quickly.
• GPR snow depth correlated with probe measurements at r = 0.70 (p = 0.00061), with a MAPE of 12.20%.
• The radar could pick out very hard and very soft layers, which matter for slab avalanches.
• The study focused on steep high-alpine terrain, where earlier UAV GPR snow work had been limited.

Where this applies in India

The same approach can support snow and ice work in mountain regions:

• snow and avalanche research by universities and institutes;
• snow depth checks along avalanche-prone mountain roads;
• snowpack data for hydropower and water-supply catchments;
• glacier studies where crews cannot safely cover large slopes on foot.

SPH Engineering's GPR training is also available through HobiTech.

The equipment, available from HobiTech

Ground penetrating radar	RadSys Zond Aero 1000 "NG"
Altitude control	A LiDAR altimeter held 5 m above the snow. See True Terrain Following for SkyHub.
Onboard computer	Not named in the case study. We supply SPH Engineering drone GPR systems with SkyHub by SPH Engineering and the SkyHub GPR software.
Drone	DJI M300 was used in this project. Ask us for current compatible drones.

Case study by SPH Engineering, published December 2023. This page summarises it in our own words; the research was carried out by GEORESEARCH and LO.LA Peak Solutions GmbH, not by HobiTech. Read the original case study on SPH Engineering ↗