Case study by SPH Engineering · GPR and bathymetry · Mining
Drone GPR and echo sounder surveys at El Cerrejón coal mine
In late 2023, SPH Engineering and DATUM Ingeniería SAS ran a field operation at El Cerrejón in Colombia, one of the world's largest coal mines. A drone-borne GPR searched for burning coal pockets beneath areas where heavy machinery works, and a drone echo sounder measured depth and sediment in a mine water reservoir.
The challenge
The fieldwork had three goals:
- find "coal pockets", areas of burning coal or subsidence, beneath ground where heavy machinery works;
- measure the depth and sediment thickness of a mine water reservoir;
- show how UgCS and DroneGIS support drone surveys, data sharing, visualisation and possible AI use.
The solution
GPR survey. The team flew a Radar Systems, Inc. Zond Aero LF ground penetrating radar with a 100 MHz antenna over two fields inside the mine. It was chosen because it reaches the depths the customer specified, so underground cavities could be found safely from the air. The data was processed in GeoHammer to map the anomalies.
Bathymetric survey. An ECT D052S dual-frequency echo sounder on a DJI M300 surveyed the whole water reservoir. Dual-frequency sonar was the best fit for measuring sediment. The data was processed in Hydromagic to show sediment layer thickness.
The results
- The GPR surveys identified possible burning coal pockets, so the mine could deal with the hazards before excavation began.
- The echo sounder gave accurate depth and sediment thickness for the reservoir, which supports water management before and after heavy rain.
- The UgCS and DroneGIS demonstrations showed the value of automated mapping and data sharing, with AI noted as a future option.
Where this applies in India
Indian opencast mines face similar ground and water risks. The same pair of surveys suits:
- checking for voids, old workings or subsidence under haul roads and working benches;
- locating hot or burning zones in coal mine areas before excavation;
- depth and sediment surveys of mine water reservoirs and sumps, especially before the monsoon;
- mine safety and planning teams who want both datasets from one drone platform.
SPH Engineering's GPR training and bathymetry training are also available through HobiTech.
The equipment, available from HobiTech
| Ground penetrating radar | RadSys Zond Aero LF |
| Echo sounder | EchoLogger ECT D052S |
| Onboard computer | SPH Engineering's integrated systems run on SkyHub by SPH Engineering, with the GPR and echo sounder software packages |
| Flight planning | UgCS - Drone Flight Planning Software |
| Drone | DJI M300 was used in this project. Ask us for current compatible drones, such as the DJI Matrice 350 RTK. |
| Processing | GeoHammer, Hydromagic and DroneGIS (used in the project) |
Case study by SPH Engineering, published August 2024. This page summarises it in our own words; the fieldwork was carried out by SPH Engineering with DATUM Ingeniería SAS, not by HobiTech. Read the original case study on SPH Engineering ↗
Need to see under the ground and under the water at your mine?
Tell us what you need to detect and the depths involved. We will specify the GPR, echo sounder, drone, SkyHub and UgCS setup, quoted in rupees with a GST invoice.