Memo 01 · Airspace Consumption
Check the airspace number every month, not once a year.
Landfill Volume flies your active cell on a monthly cycle and measures the new surface against the last one, so the remaining airspace you put next to the permit limit comes from a measurement and not from tons received and an assumed density.
- GSD
- sub-10 cm
- Cadence
- Monthly
- Platform
- Drone or crewed aircraft
- Spectral
- RGB
Between surveys, the airspace number is a guess
The surveyor's topo comes in on its own schedule. In between, the ledger runs on tons through the scale house and a density someone settled on earlier.
When the next survey lands and the void is smaller than the ledger said, the fill sequence has been planned on the wrong number for months. The permit review and the closure date inherit the difference, and the engineer is the one explaining it.
The same year of airspace, tracked two ways
The airspace ledger between surveys
Periodic survey and tonnage
Tons received, times a density factor you settled on, subtracted from the last surveyed airspace.
With Landfill Volume
A new surface of the active cell each month, so each ledger line comes from a measured volume.
Still yours
The density factor. It is how you turn our volume into tons, and you keep it.
Fixing the consumption rate
Periodic survey and tonnage
One long interval between surveys gives one average rate, and a fast stretch hides inside it.
With Landfill Volume
Airspace used month by month, read from successive surfaces, so a change in rate shows up in the month it happens.
Spotting a fill sequence drifting
Periodic survey and tonnage
You find that a lift ran high or a slope came in steep when the survey is drawn.
With Landfill Volume
Each monthly surface shows where the active cell has built up, set against the last one.
Still yours
Deciding what the sequence should do about it.
Counting cover soil
Periodic survey and tonnage
Cover is estimated separately, or folded into the density factor.
With Landfill Volume
Cover soil sits in the surface like everything else the cell has added, so the cut/fill figure includes it.
Preparing for the permit review
Periodic survey and tonnage
The last surveyed figure, rolled forward with the tonnage estimate.
With Landfill Volume
The latest monthly airspace-balance table against the permitted capacity you supplied, with the surface behind it.
Still yours
The licensed survey, where your permit or regulator requires one. This is a photogrammetric measurement you can cross-check against it.
Closure and next-cell timing
Periodic survey and tonnage
The date airspace runs out is projected from the last annual figure.
With Landfill Volume
You project the run-out date from a recent surface and a rate measured over recent months.
What lands each month
One set of files per monthly flight of the active cell, in forms your CAD, GIS and spreadsheet already open.
GeoTIFF
Monthly surface model
The photogrammetric surface of the active cell, ready for Civil 3D, a GIS or whatever you difference surfaces in. It is the file behind every number we report.
Ledger row 03Spotting a fill sequence drifting
PDF
Cut/fill volume report
Volume added and removed against the prior month's surface, for the cell footprint. It ties each figure to the two surfaces it came from.
Ledger row 04Counting cover soil
CSV
Airspace-balance table
A running ledger of airspace used against the permitted capacity you supply, one line per flight. It drops into the spreadsheet you already keep.
Ledger row 01The airspace ledger between surveys
Flight note
A note on each flight
The date flown, anything that limited the capture, and any gap where a month was missed.
Ledger row 05Preparing for the permit review
Through the fill year
You send the cell and the permit figure once. A surface comes back each month.
At the start
Send your cell and your capacity
The active cell boundary, the permitted capacity and the final-grade surface if you have one, plus the date and surface of your last survey.
Every month
Monthly flight
A drone or aircraft flies the active cell. Imagery at sub-10 cm resolution is processed to a surface model.
Compare to last month
The new surface is differenced against the previous one for cut/fill, and the airspace balance is updated against your capacity.
Report and ledger line delivered
Surface, volume report, balance table and flight note for your monthly ledger.
What the periodic survey still does better
Read these before you put a month's figure in the permit report.
Not a licensed survey
This is a photogrammetric measurement. Where your permit or regulator requires a licensed land survey, you still commission it. Use our surfaces to cross-check it and to fill the months in between.
Surface volume, not waste density
We measure the volume between surfaces. We do not measure what is in place, and tons or compaction conversion is not part of the delivery.
No published accuracy figure
How close a surface lands depends on flight conditions, ground control and site geometry. We do not put one accuracy number on the page. Ask about your site.
Weather decides the flight
A monthly flight is the target. Wind, rain, snow cover or standing water can push it to the next clear window, and the flight note records the gap. We do not promise a delivery date regardless of conditions.
Sub-10 cm resolves the surface
A pixel at this size is fine for the shape of a lift or slope. It will not resolve hairline features, and open working-face detail changes by the hour.
RGB only
The imagery is visible light. No thermal and no gas or leachate reading comes with it.
Who it's for
Switch if
- You are the site engineer who owns the airspace number and answers for it at the permit review.
- You keep a running ledger of remaining airspace and want a measured line in it every month.
Stay with the periodic survey if
- Your permit or regulator needs a licensed land survey for the figure. Keep it, and use this between surveys.
- You need tonnage, density or compaction. We deliver volume only.
- You need gas, leachate or temperature monitoring.
Before you add it to the ledger
Does this replace our licensed land survey?
It may not. It is a photogrammetric measurement. Check what your permit or regulator requires for the figure you report. Keep the licensed survey where it is required, and use this to cross-check it.
How do we check it against our own survey?
Difference our surface against your surveyor's on the same date, or compare the volume between two dates. If the two disagree, send both and we will go through the flight with you.
What happens if a flight is weathered out?
The flight moves to the next clear window and the flight note records the gap in the ledger.
How is compaction handled?
It is not. We deliver surface volume. You apply your own tons-to-volume conversion.
What accuracy should we expect?
We do not publish a blanket figure. It depends on flight conditions and site geometry, so ask about your cell.
Can the cadence be faster than monthly?
Monthly is the planned cycle. If your fill rate needs a different interval, talk to us.
What do we open the files in?
A GeoTIFF surface opens in Civil 3D or a GIS, the balance table is a CSV, and the report is a PDF. There is no direct integration with scale-house or ledger software.
Who owns the surfaces and imagery?
Your boundary and capacity figures stay yours. Rights to the surfaces and the imagery behind them are written into the project agreement before the first flight.
How is it priced?
It depends on the size of the cell and how many months you want covered, so we quote after we have seen the site. There is no price list on this page.
Put next month's number in the ledger.
Send the active cell, your permitted capacity and the date of your last survey. We will scope the monthly run from there.
Start a project