6.2 · Intermediate

Mining and GNSS: Pit Optimization and Safety

Introduction

Mines are among the most challenging GNSS environments, deep pits, high walls, massive equipment. Yet GNSS is essential for safety, efficiency, and compliance.

The Mining Environment

Challenges include deep pits (limited sky view), high walls that block satellites, dust (equipment protection), vibration, and remote locations with no cellular coverage. Requirements are extreme: continuous 24/7/365 operation, high reliability, safety-critical applications, and integration with other mine systems.

Mine Surveying

  • Exploration: Initial mapping of deposit, reserve calculations, permit applications
  • Operational surveying: Pit progression monitoring, volume calculations, blast hole layout, grade control
  • As-built: Reclamation planning, final topography, closure documentation

GNSS is faster for open pits, but total stations are needed for deep pits with limited sky view. A combination is typically used.

Machine Control in Mining

  • Drills: Position blast holes precisely for optimal fragmentation, reduce over/under drilling
  • Shovels/excavators: Dig to planned grade, track material type, optimise loading
  • Haul trucks: Fleet management, collision avoidance, and autonomous operation at some mines

High-Precision Requirements by Operation

OperationAccuracyTechnology
Exploration drilling1–5 mHandheld GPS
Blast hole layout10–20 cmRTK rover
Grade control10–30 cmRTK on shovel
Survey measurements2–5 cmRTK / PPK
Autonomous trucks5–10 cmRTK + INS
Deformation monitoring1–2 cmContinuous GNSS

Fleet Management Systems

Real-time truck positions enable optimal dispatch (minimise waiting at shovels), cycle time analysis, and productivity reporting. Safety features include proximity alerts between equipment, speed monitoring, and restricted area enforcement.

Slope Stability Monitoring

This is the most critical safety application in mining. Pit walls can fail suddenly, endangering equipment and lives. Permanent GNSS stations on pit walls measure millimetre-level movements continuously, alerting before failure and providing time to evacuate. Combined with radar for wide-area coverage, GNSS provides the absolute position reference that makes monitoring systems work.

Autonomous Mining

Fully autonomous haul trucks, using RTK + INS for navigation with no driver in the cab, operate 24/7 at major operations including Rio Tinto and BHP. Autonomous drills position themselves and execute complete drill patterns. Benefits: safety (remove people from hazardous areas), productivity (continuous operation), and consistency (repeatable patterns).

Vital Points

  • Mining is a demanding GNSS environment, deep pits, high walls, dust, vibration
  • RTK and PPK used for survey and machine control
  • Fleet management optimises equipment utilisation
  • Slope monitoring protects lives with early warning of wall failure
  • Autonomous mining is reality at major operations today
  • Combination with other sensors (radar, INS) is common