How often should a stockyard be measured?

For financial close, monthly is the minimum defensible cadence. Thermal plants typically close monthly; steel mills monthly with mid-month interim checks; mining operations quarterly with ad-hoc triggers on major movement. Flybi runs these on a calendar, not a request.

What's the difference between drone photogrammetry and LiDAR for stockpiles?

Photogrammetry is sufficient for most bulk stockpiles with clear texture (coal, iron ore, aggregates). LiDAR is preferred for piles under vegetation, sheltered yards, or covered materials where photogrammetry struggles. Flybi selects the sensor per site — sometimes both, if the yard has a mix.

Flybi / Services / Stockpile Intelligence

Product 02 · Stockpile Intelligence

Close the books on what you’re sitting on.

Audit-grade monthly stockpile measurements for thermal plants, steel mills, and mining operations. A 500-acre yard captured, processed, and reconciled in under 48 hours — with ±1.5% variance against weighbridge data.

Scope a Yard Request Sample Report

Stockpile volume mesh — 3D triangulated surface with contour lines

The problem

"Broadly estimated" closing inventory is a billion-rupee accounting habit.

In most thermal plants and steel mills, closing inventory is still derived from rope-and-tape surveys, angle-of-repose guesses, or — bluntly — last month’s number plus judgement. The variance hides inside "normal loss" buckets. When auditors dig, variances of 5–10% are not unusual. On a 500,000-tonne coal yard, that is a material number.

The downstream effects compound: PLF reports become suspect, fuel-cost reconciliation drifts, statutory filings get qualified, and finance loses leverage over operations. The root cause is that nobody has defensible, repeatable, audit-grade tonnage — they have a best guess and a willingness to argue for it.

The Flybi solution

A monthly audit that runs like a payroll cycle.

Fixed calendar. Fixed scope. Fixed deliverable format. Zero improvisation. The same team, the same sensors, the same pipeline — so month-over-month numbers are comparable, auditable, and defensible against external review.

Capture

Calibrated drone flights with GCPs

RTK-enabled drones on pre-planned grids. Ground control points at known survey marks for accuracy anchoring. Flight times sized to pile geometry — not set by operator habit.

Process

Hardened photogrammetric pipeline

Dense point cloud → Digital Surface Model → per-pile segmentation → volumetric calculation against a named base plane. Every step reproducible, every version tracked.

Reconcile

Weighbridge-anchored sign-off

Final tonnage reconciled against weighbridge receipts or truck-count data for that period. The variance is in the report, not hidden in it.

Under the hood

The technical spec, simplified.

Sensor stack

RGB photogrammetry + LiDAR on demand

20 MP+ global-shutter RGB cameras
RTK-level GNSS positioning
LiDAR option for sheltered / covered yards
Thermal overlay for self-heating stockpiles

Ground control

Survey-grade anchoring

Permanent GCP network per site (installed once, reused monthly)
DGPS / RTK survey of each GCP to ±2cm
Check points held out of the solution for QA

Processing

Versioned photogrammetric pipeline

Dense matching to sub-5cm point-cloud density
DSM + DTM generation
Per-pile geometry extraction
Volumetric calculation against named base planes

Audit trail

Defensible in a finance review

Sensor, flight, GCP, and processing metadata embedded
Check-point residuals published in report
Reconciliation against weighbridge inline
Signed PDF + CSV archive retained for 7 years

Deliverables

What lands in your CFO’s inbox, every month.

/01

Audit-grade PDF

Per-pile volume & tonnage, check-point residuals, weighbridge reconciliation, sign-off panel.

/02

Signed CSV

Machine-readable line item per pile — ready to load into SAP, Tally, Zoho Books, or custom ERP.

/03

DSM & DTM

GeoTIFF surface models, retained as the geometric record for the period.

/04

Month-over-month delta

Movement volume, net change per pile, anomaly flags for piles with unusual variance.

/05

Historical baseline

Rolling 12-month trend per pile. Shrinkage, pilferage, or measurement drift becomes visible over time — not buried in it.

/06

API feed (optional)

Direct JSON feed into your dashboards or ERP. No portal-hopping. No CSV re-keying.

Commercial impact

The finance-economics case.

±1.5%

Typical variance vs weighbridge

48hrs

Capture to verified report

5–10%

Typical variance on manual surveys replaced

On a 500,000-tonne coal yard at ~₹3,500/tonne blended landed cost, moving from a 5% variance to a 1.5% variance means ₹6+ crore of inventory moves from the "estimated" column to the "measured" column. That is defensible tonnage on your books — not rhetoric.

Flybi vs alternatives

Why a plant head picks Flybi.

Flybi delivers

Monthly calendar — no request-raising, no project setup each cycle
Single reconciled tonnage number, with variance inside the report
Historical baseline that makes movement visible, not theoretical
Audit-grade artifact your statutory auditor cannot qualify
Operations + finance alignment on one defensible number per pile

Manual and ad-hoc alternatives give you

Rope-and-tape surveys with 5–10% variance hidden in "normal loss"
Project-by-project drone vendors with no comparability month-over-month
Fragmented data — different file formats, different vendors, different accuracies each cycle
No historical trend; each measurement is an island
Arguments between ops and finance that nobody has defensible data to resolve

Answers

Common questions on stockpile deployments.

What is stockpile volume measurement?

It is the precision calculation of bulk-material tonnage using aerial imagery or LiDAR. A calibrated drone captures the pile; processing produces a digital surface model; volume is computed against a reference base plane, multiplied by bulk density to give tonnage. Sub-2% accuracy against weighbridge is standard with ground control.

How often should a yard be measured?

For financial close, monthly is the minimum defensible cadence. Thermal plants close monthly; steel mills typically monthly with mid-month interim checks; mining operations quarterly with ad-hoc triggers on significant movement. Flybi runs these on a fixed calendar — you don’t re-initiate each cycle.

Does operation stop during capture?

No. Flights are planned around operational activity and cleared with site safety. For yards with continuous truck movement, we capture during low-activity windows and stitch. For active faces, we time-bin the capture and reconcile against the weighbridge movement in that window.

What about covered or sheltered stockyards?

For piles under sheds, canopies, or dense vegetation, we switch to LiDAR — sometimes ground-based SLAM for fully enclosed spaces. The pipeline downstream is identical. The report format is identical. Only the sensor changes.

How do you handle bulk-density variation?

We do not assume density. We work with your existing laboratory density values per material class and publish the volume-to-tonnage conversion factor in the report. If you want us to run periodic bulk-density sampling as part of the engagement, we can arrange that through a laboratory partner.

Can this replace our statutory stock verification?

Yes — with your auditor’s written sign-off. Flybi’s audit-grade report format has been designed to satisfy statutory stock verification requirements for thermal and steel operators in India. In practice, most enterprises run Flybi monthly and have the statutory auditor observe a sample Flybi mission annually.

Book your next close

Measure the yard. Close the month. Move on.

Tell us about the yard — acreage, material, existing audit cadence, weighbridge setup — and we’ll return a scoped monthly engagement plan within 48 hours.

Scope a Yard Request Sample Report