Stockpile measurement · Comparison

Stockpile monitoring without the drone.

Drones give you one snapshot a month — when the weather allows, when the pilot is on site, when the airspace is clear. LiDAR gives you the same volume number every minute, in any weather, with nobody in the loop.

The short answer first

Drone for project surveys. LiDAR for operations.

A drone survey produces a photogrammetric point cloud from a single flight — accurate enough for a monthly volume report, but only at that moment, only when weather and airspace cooperate, and only with a certified pilot on site.

Stationary LiDAR works differently. Sensors mounted on masts, gantries or hall structures scan the yard continuously, around the clock, in rain, dust, fog and at night. Each scan updates per-pile volume in the dashboard — operations sees the live number, finance sees the month-end number, both come from the same source.

For one-off as-built surveys or remote sites a drone is fine. For any yard where the volume number drives daily dispatch, reconciliation or contract release, continuous LiDAR is the right call.

„A drone tells you what the pile looked like last Tuesday at 10:42. LiDAR tells you what it looks like right now."

Many sites keep a drone for occasional aerial documentation and run LiDAR for the daily inventory number. All six system classes side by side: stockpile monitoring systems compared.

Side-by-side

LiDAR vs drone for stockpile monitoring.

Dimension Drone survey OWL EYE® Stockpile (LiDAR)
Cadencesnapshot — typically monthlycontinuous — every minute, 24/7
Operatorcertified pilot + spotternone — runs unattended
Weather windowgrounded in rain, wind, low lightoperates in rain, dust, snow, fog, night
Regulatoryflight permit, BVLOS rules, exclusion zonesnone — fixed installation
Accuracy1–3 % with GCPs, 3–5 % without±1 % volume, surface-fitted
Time to resulthours to days post-flightlive — dashboard within minutes
Indoor / sheltered yardsnot possible — GPS / open sky neededworks — overhead-mounted, no GPS
„If you need a number every day, you cannot fly every day. LiDAR runs while everyone else waits for the weather."
Where LiDAR replaces the drone

Five operations where LiDAR is the right call.

Daily dispatch & reconciliation

When the volume number drives daily intake/reclaim decisions — a monthly drone flight is too slow.

Indoor & roofed storage

Drones need open sky and GPS. LiDAR works under roofs, in halls, inside silos and tunnels.

Hazardous or restricted airspace

Ports, refineries, mines, ATEX zones, urban sites — places where flying is restricted or impossible.

Bad-weather sites

Rain, fog, dust, night-shift operations — LiDAR keeps measuring when the drone is grounded.

Continuous-process plants

Sugar, cement, fertiliser, mineral processing — where stockpile turnover happens hourly, not monthly.

Where a drone still wins

Two scenarios where a drone is the right call.

One-off as-built surveys

A single capture for a permit, an audit or a site handover. A drone flight + photogrammetric report is fast and cheap.

Vast remote sites without infrastructure

Hundreds of hectares with no power, no network, no masts — a mobile drone team is the practical answer.

Why Sachtleben

From snapshot to live inventory.

OWL EYE® STOCKPILE replaces the monthly drone routine with a continuous volume signal — and we will tell you when the drone is still the right tool.

No pilot, no permit, no weather window

Fixed-mount LiDAR runs unattended around the clock, in any conditions.

Same number for operations and finance

Live volume in the operations dashboard, month-end snapshot for the books — one source.

ERP / PLC integration

OPC UA, REST, file-export — the volume number lands where you need it without manual upload.

Honest about the trade-off

If you only need one-off surveys, we will say so. We design the right tool, not the bigger sale.

FAQ

LiDAR vs drone — common questions.

Decision-relevant questions buyers ask before choosing between drone surveys and continuous LiDAR.

Comparison

When is Radar actually a better choice than LiDAR?+
Three clear cases. (1) Permanent heavy dust — cement clinker bunkers, coal silos with constant dust circulation. LiDAR's optical window blinds within hours; Radar sees through. (2) Single-point fill-level only — you don't need surface shape, just average height. Radar is simpler, cheaper to maintain. (3) Very long ranges (>300 m) — LiDAR signal-to-noise drops; Radar maintains useful return at km-scale. For everything else — clean indoor storage buildings, multi-zone piles, billing-grade accuracy, conveyor cross-sections, truck-load shapes — LiDAR's resolution wins by an order of magnitude.
Stockpile measurement vs stockpile monitoring — what's the difference?+
Stockpile measurement is a single capture event with a numeric result — volume in m³, tonnage in t, signed report. It answers the question: "How much is in this pile right now?" Manual surveys, drone flights and terrestrial laser scans are all measurements. They are point-in-time snapshots. Stockpile monitoring is a continuous stream of measurements over time, with trend, FIFO aging, dead-inventory detection and alarms. It answers: "How did this pile evolve over the shift, the week, the year — and what should we do next?" Periodic measurement is enough for audits, year-end stocktaking or due diligence. Continuous monitoring is required for operational decisions: dispatch planning, reclaim sequencing, throughput reconciliation against weighbridge tickets, alarm on overfill or unexpected reclaim. OWL EYE® STOCKPILE delivers both on the same platform: each individual scan is a fully signed measurement with ±1% accuracy, and the time-series of those scans — archived as 3D block models — is the monitoring layer. Customers run it 24/7 in live mode or on a schedule (per shift, per hour). For one-off survey-grade audits we additionally offer Bulk Inventory with a terrestrial Riegl scanner.
Doesn't dust kill LiDAR? How do you handle dusty environments?+
Dust degrades LiDAR but rarely kills it. Three layers of mitigation: (1) Multi-echo signal processing — modern industrial LiDAR returns multiple echoes per pulse and the algorithm picks the right one (the dust echo gets filtered out). (2) Optical-window cleaning — once-a-year visual inspection in normal industrial settings, every 6 months in dustier ones. (3) Compressed-air auto-cleaning — optional pulse on the window every 30 min, available on all OWL EYE® platforms for very dusty installations (cement, salt, fertilizer). In our experience: LiDAR works fine in 90 % of "dusty" industrial environments. The 10 % where it doesn't are the cases where Radar legitimately wins.
What about ultrasonic sensors? They're cheaper.+
Ultrasonic is fine for single-point fill-level in small vessels (under ~10 m, calm material, no temperature gradients). It fails on every dimension that matters for industrial bulk-material monitoring: range maxes out around 10-15 m, accuracy is ±5-10 % on uneven surfaces, dust and vapour scatter the sound waves, and there's no surface-shape information at all — just one average distance. Cost is the only LiDAR-vs-ultrasonic argument. For one small dosing hopper at €500 it's the right call. For anything stockpile-scale, the price difference is dwarfed by the inventory error you accumulate over a year.
How does LiDAR compare to a belt scale?+
Different jobs. A belt scale measures mass flow at one specific belt — accurate to 0.5-1 % when calibrated, but only at that point and only for the moving material. LiDAR measures volume in any geometry: stockpiles, bunkers, trucks, plus the cross-section of moving belts. In practice they complement each other. The belt scale is your reference for material on a single belt. LiDAR gives you stockpile inventories, bunker fill, truck-load profiles, multi-belt overview, and FIFO tracking — none of which a belt scale can do. Sachtleben uses both: LiDAR for everything stationary or geometric, belt scales as a periodic re-calibration reference for the LiDAR mass output.
How does LiDAR compare to a drone survey for stockpiles?+
Different jobs. A drone survey produces a photogrammetric point cloud from a single flight — accurate to 1–3 % with a surveyed network of ground control points and 3–5 % without, but only at that moment, only when weather and airspace cooperate, and only with a certified pilot on site. Stationary LiDAR like OWL EYE® STOCKPILE measures continuously, 24/7, in rain, dust, snow, fog and at night — no pilot, no airspace permit, no weather window. Each scan updates per-pile volume in the dashboard within minutes, so the operations team and finance work from the same live number. In practice: drones make sense for one-off as-built surveys or vast remote sites without infrastructure. For any yard where the volume number drives daily dispatch, reconciliation or contract release, continuous LiDAR is the right call. See LiDAR vs drone for stockpile monitoring for the full side-by-side.
Why not just stick with manual surveying or drone flights?+
Frequency and cost. A manual survey or drone flight gives you a snapshot — accurate (we offer it as a service ourselves), but valid only for the moment of capture. The next morning, after a shift of intake and reclaim, your inventory is wrong again. Permanent LiDAR gives you the same accuracy continuously, every 5 minutes if you want, around the clock. For a typical mid-size industrial site that runs 200+ shifts per year, the case for permanent LiDAR is not the price of the surveys it replaces — the inventory is usually surveyed one to four times a year — but the time between them, when inventory discrepancies of typically 2–4 % against book stock go unseen. Plus you get FIFO tracking, alarms, and shift-by-shift reporting that periodic surveys can't deliver at any cost.
How does LiDAR compare to a weighbridge for truck dispatch?+
For dispatch, the comparison is one-sided. A weighbridge produces one mass number per truck after a 30–60 s stop-tare-ticket cycle, and tells dispatch nothing about how the truck is loaded. A LiDAR drive-through gantry produces a full 3D load shape in 8 s: volume, per-zone fill, centre of gravity and an under-/over-fill flag — all delivered while the truck is still under the gantry. In practice this means LiDAR catches problems the weighbridge cannot see at all: a truck whose volume is correct but whose density is wrong (mixed material), a tipper loaded heavily on one side, a partial fill that the contract penalises. Dispatch decides at the gantry exit, not after the truck has already left the yard. The full side-by-side data table is on the LiDAR vs weighbridge page.
What is the throughput advantage of LiDAR vs a weighbridge?+
A single weighbridge with a stop-tare-ticket cycle of 30–60 s clears ~60 trucks per hour at peak — and that is a clean theoretical peak; real operations with a queue and ticketing fall well below it. A two-lane OWL EYE® Truck Terminal gantry, drive-through at 5 km/h with an 8 s scan, sustains 200+ trucks per hour. The throughput gap matters most during shift-change peaks at quarries and recycling yards, where a queueing weighbridge becomes the bottleneck for the entire site. The LiDAR gantry removes that bottleneck without adding personnel — drive-through means the driver does not leave the cab, no operator ticket, no scale-house manning. The full throughput line is in the LiDAR vs weighbridge data table.

Tired of waiting for the next drone flight?

Tell us your yard — outdoor or indoor, number of piles, current survey cadence. We come back with a concrete LiDAR proposal and an honest word on whether the drone still has a job, within one business day.

info@sachtleben-technology.com+49 7831 969 22-190