Underground mine mapping Drone Guide

Underground mines are among the most complex environments in which surveying and inspection teams operate. Tunnels, stopes, shafts, drifts, crosscuts, chambers, ore passes, ventilation routes, loading areas, and abandoned workings can extend for many kilometres below the surface. Maintaining accurate maps of these environments is essential for mine planning, production management, ventilation design, geological interpretation, infrastructure maintenance, emergency preparedness, and worker safety. Traditional underground mine surveying relies on total stations, laser scanners, GNSS at the surface, handheld mapping systems, and specialist survey teams. These methods remain fundamental, but some underground areas can be difficult, slow, or hazardous to access. Drone technology provides another option. Specialist underground drones can operate without conventional satellite navigation and can carry LiDAR, visual cameras, thermal sensors, lighting systems, and navigation technology designed for GPS-denied environments. They can enter tunnels, stopes, cavities, shafts, and other spaces to collect three-dimensional information while reducing the need for personnel to physically enter every location. For mining companies, surveyors, geotechnical teams, engineers, and mine planners, underground drone mapping is becoming an increasingly valuable component of digital mine management. ## **Why Underground Mapping Matters** An underground mine changes continuously. New tunnels are developed, stopes are excavated, ore is removed, support systems are installed, and infrastructure is modified as mining progresses. Accurate mapping allows mine planners to understand the current geometry of the workings. This information influences production planning, equipment movement, ventilation, drainage, ground support, and future excavation. If mapping is outdated or incomplete, mine planning becomes more difficult and operational risk can increase. ## **GPS-Denied Navigation** One of the biggest challenges underground is the absence of reliable GNSS signals. Conventional drones commonly depend on satellite positioning for navigation and stability. Underground drones instead use combinations of LiDAR, cameras, inertial sensors, visual odometry, and Simultaneous Localisation and Mapping, commonly known as SLAM. These technologies allow the aircraft to estimate its position relative to the surrounding environment. The drone effectively builds a map while using that same map to navigate. ## **LiDAR Mapping** LiDAR is one of the most important technologies for underground mine mapping. The sensor emits laser pulses and measures the returned signals to create a three-dimensional point cloud. As the drone moves through a tunnel or chamber, millions of measurements can be collected. The resulting point cloud represents walls, floors, ceilings, structures, and other visible surfaces. This information can be used to create detailed digital models of underground workings. ## **Simultaneous Localisation and Mapping** SLAM enables a drone to navigate through an environment without external positioning. The system continuously compares incoming sensor information with previously observed features. This allows the aircraft to estimate both its own movement and the geometry of the surrounding space. SLAM is particularly valuable underground because tunnel environments can be narrow, dark, and geometrically repetitive. High-quality sensor fusion is therefore essential for reliable mapping. ## **Stope Mapping** Stopes can contain large irregular cavities created during ore extraction. These spaces may be difficult or unsafe for personnel to enter. Drones can fly into suitable stopes and collect LiDAR or photogrammetric information. The resulting three-dimensional model can help mine planners understand the shape and volume of the excavation. This information can support production reconciliation and future planning. ## **Void Mapping** Underground mines can contain natural or man-made voids that are difficult to observe directly. Specialist drones can inspect suitable cavities and generate three-dimensional models. This can provide engineers with information about size, shape, orientation, and surrounding geometry. Remote mapping is particularly valuable where direct human access is undesirable. ## **Shaft Inspections** Vertical shafts can be difficult to inspect because of their depth and restricted access. Specialist drones can potentially travel through suitable sections while collecting imagery and LiDAR information. They can document visible shaft walls, structures, services, and other infrastructure. Operations require careful planning because confined vertical environments can create communications and recovery challenges. ## **Tunnel Mapping** Underground tunnels are one of the most common mapping environments. A drone can travel through suitable drifts and crosscuts while collecting point-cloud data. The resulting model can show tunnel geometry, intersections, ground conditions, and installed infrastructure. Repeated surveys can keep the digital mine map current as development progresses. ## **Decline and Ramp Mapping** Declines and ramps provide vehicle access between underground levels. Their geometry is important for truck movement, drainage, and mine planning. Drone mapping can provide high-resolution three-dimensional information about these routes. Point clouds can help planners understand gradients, widths, clearances, and visible surface conditions. ## **Ore Pass Inspections** Ore passes transport broken material between levels. These structures can be difficult and potentially hazardous to inspect directly. A specialist drone can collect imagery or LiDAR information from accessible sections. The resulting data can help engineers understand visible geometry and identify areas requiring further investigation. Specialist mining procedures remain necessary because ore-pass environments can be unstable. ## **Ventilation Infrastructure** Ventilation is critical to underground mine safety and productivity. Drones can help map ventilation tunnels, raises, ducting, doors, and other visible infrastructure. Accurate three-dimensional information can support mine ventilation models. The drone does not replace airflow monitoring or ventilation engineering, but it can improve the geometric information used within those systems. ## **Ventilation Raise Mapping** Raises and vertical ventilation openings can be difficult to inspect manually. Specialist drones can enter suitable spaces and collect three-dimensional information. This can help teams understand internal geometry and identify visible changes. The resulting model can support engineering analysis and maintenance planning. ## **Ground Support Inspections** Underground workings often contain bolts, mesh, shotcrete, steel sets, and other support systems. High-resolution cameras can document visible support infrastructure. LiDAR can provide geometric information about surrounding surfaces. The drone can help identify areas that warrant closer geotechnical review. It does not replace professional ground-control inspections or physical testing. ## **Rock Face Mapping** Freshly exposed rock faces provide valuable geological information. Drones can photograph or scan these surfaces in high detail. Three-dimensional models can support structural geology, fracture mapping, and digital geological records. This can be particularly useful where faces are difficult to observe safely from the ground. ## **Geological Mapping** Underground drones can support geological teams by documenting rock structures, contacts, fractures, and other visible features. High-resolution imagery provides visual information, while LiDAR adds geometric context. These datasets can be integrated with borehole, assay, and geological model information. The result is a more complete digital representation of underground geology. ## **Volume Measurement** Three-dimensional