Mine surveying: methods, instruments and what a mine surveyor does

What is mine surveying?

Mine surveying is the branch of surveying that measures, plans and controls the position of everything in a mine: the surface, the pit, shafts, declines, drives, stopes, stockpiles and infrastructure. It turns the mine design into marks on the rock and turns what was actually excavated back into accurate plans and volumes.

Universities and professional bodies often call the discipline mining and mine surveying, because it overlaps with mine planning, geology and geotechnical engineering. Day to day, mining surveying has three goals:

• Direction – keep development on the designed alignment and gradient so drives hole through where planned.
• Records – maintain up-to-date mine plans showing every opening, which in many jurisdictions is a statutory requirement.
• Quantities and safety – measure tonnes moved, check excavations against design, and warn of proximity to old workings, water or unstable ground.

What does a mine surveyor do?

A mine surveyor sets out where the mine is to be excavated, measures what has been excavated and keeps the mine's plans and control network accurate. The role combines field work in the pit or underground with office work on plans, models and reports.

A typical month for a mining surveyor includes:

• Extending and checking the survey control network as development advances.
• Marking line and grade for drives and declines, and laying out drill-hole collars, blast patterns and bench toes and crests.
• Picking up advances, stope voids and pit faces, often by laser scanning.
• End-of-month volume and tonnage reconciliation for mine management and contractors.
• Monitoring pit walls, subsidence and convergence, and reporting movement against alarm thresholds.
• Updating statutory mine plans and checking safety distances to boundaries, old workings and water.

Accuracy and traceability matter as much as speed: a 1° azimuth error in a 500 m drive moves the face nearly 9 m off line, so mine surveyors check everything twice.

How is surveying in mines different for open-pit and underground operations?

Open-pit work is mostly done with GNSS RTK, drones and long-range scanners, while underground work relies on total stations, traverses and scanners because there is no satellite signal. The goals are the same; the methods and hazards differ.

Many operations run both, so one surveying team keeps surface and underground data in the same mine grid.

How is survey control carried underground?

Control is transferred underground by connecting surface GNSS control to the underground workings through a portal, decline or shaft, then extending it with total station traverses. Because errors accumulate along a traverse, the method includes independent checks at every stage.

1. Establish surface control with static GNSS or RTK on stable monuments near the portal or shaft collar, tied to the mine grid.
2. Carry coordinates in. Through a decline or adit, run a traverse from the surface marks. Through a vertical shaft, transfer position with plumb wires or an optical or laser plumb, and height with a calibrated tape or EDM measurement down the shaft.
3. Fix the orientation. Shaft plumbing gives a very short base for azimuth, so many mines check bearing with a gyro-theodolite (a north-seeking instrument) on long traverses.
4. Traverse with forced centring using roof stations and three-tripod or bracket setups so the instrument and targets swap without centring errors.
5. Close loops wherever development connects, and compute misclosures before relying on new stations.
6. Re-observe periodically, because roof stations move with blasting and ground convergence.

A dual-axis compensated total station with good angle accuracy is the core tool. Our STSA9 Android total station offers 2" angle accuracy, 1500 m reflectorless range and a dual-axis compensator, with a 5-inch touch screen on each face that is easier to read in poor light than a small keypad display. For the fundamentals of how these instruments measure, see our total station guide.

Which instruments do mine surveyors use?

Mine surveyors use total stations for control and setting out, laser scanners for pickups, GNSS RTK on the surface and drones over pits and stockpiles. The table summarises where each tool fits.

Our scanning total station combines precise angles and distances with 3D scanning and imaging in a 360° × 282° field of view, which suits tunnels and monitoring where scan data must sit on accurate control. More options for the sector are on our 3D scanning and mining solutions page.

How do mine surveyors measure volumes and reconcile production?

Mine surveyors measure volumes by comparing a new surface or void model with the previous one (or with the design) and converting the difference to tonnes using material density. This end-of-month survey is the reference against which truck counts, mill figures and contractor claims are checked.

The usual workflow is:

1. Pick up faces, benches, stopes and stockpiles close to the month-end cut-off.
2. Build surfaces or closed solids and compare them with the last survey and the design.
3. Report cut and fill volumes, and overbreak and underbreak against design shapes.
4. Apply density and swell factors agreed with geology and processing to get tonnes.
5. Reconcile surveyed tonnes against haulage records and plant throughput, and investigate differences.

Survey precision is rarely the weak link; density, moisture and the cut-off timing usually carry more uncertainty. Our stockpile volume measurement guide compares GNSS, drone and scanner methods for the surface part of the job.

When should a mine use laser scanning or SLAM?

Use a tripod-mounted laser scanner when you need survey-grade, repeatable point clouds tied to control, and use handheld SLAM when speed and access matter more than the last centimetre. Most mines end up using both.

• Terrestrial scanning suits pit-wall deformation, crusher and shaft inspections, and as-built checks of drives against design. Our high-speed terrestrial laser scanner scans at up to 1000 kHz over 0.6–150 m with an eye-safe Class 1 laser.
• Handheld SLAM scanning suits weekly drive pickups, stope brows and areas where tripod set-ups are slow. Our handheld SLAM laser scanner weighs 925 g, ranges 0.1–70 m and gives point-cloud thickness of 1 cm or less after post-processing.

Our engineers' field tip: SLAM drifts in long, featureless drives, so scan closed loops where possible and include surveyed targets every few hundred metres. The method and its limits are explained in our SLAM and mobile mapping article.

How are pit walls and ground movement monitored?

Ground movement is monitored by repeatedly measuring fixed targets or surfaces and comparing each epoch with a baseline. Automated total stations reading monitoring prisms, GNSS monitoring receivers and repeat laser scans are the standard survey methods.

Good monitoring practice includes:

• Reference stations outside the zone of influence, checked regularly against stable control.
• Short, regular measurement cycles in active areas, with movement and velocity alarm thresholds agreed with the geotechnical engineer.
• Atmospheric corrections for long EDM sights, since temperature and pressure change distances by several parts per million.
• Repeat scans with the same set-ups for surface change detection between epochs.

How do you become a mine surveyor? Qualifications, jobs and vacancies

Most mine surveyors hold a diploma or degree in surveying, geomatics or mine surveying and then build supervised experience at a mine. In several mining countries, the senior surveyor responsible for statutory plans must also hold a government-issued certificate of competency, which requires exams and documented experience.

Useful skills include total station and GNSS operation, CAD and mine planning software, point-cloud processing, and a solid grasp of coordinate systems and error propagation. Mine surveyor jobs range from graduate field roles to chief surveyor, and contractors and consultancies also hire for project work. Mine surveyor vacancies are usually advertised by mining companies, mining contractors and professional surveying institutes, and roles at remote sites often run on fly-in, fly-out rosters.

How to choose mine survey equipment

Choose mine survey equipment for the environment first and the specification second. Check these points before you buy:

• Dust and water sealing – check the IP rating against conditions; wet, dusty drives are hard on optics and electronics.
• Hazardous areas – standard survey instruments are generally not certified for explosive atmospheres, so confirm site rules before using any electronic instrument in coal or gassy mines.
• Battery and temperature – carry spares; deep mines can be hot, and pit rims can be very cold.
• Display and illumination – a readable screen and illuminated reticle save time in the dark.
• Software and export – make sure point clouds and observations load into your mine planning workflow.

If you are equipping a new survey department or replacing ageing instruments, tell us about your mine type and workflow and request a quote for a matched total station and scanner package.

Frequently asked questions