Landfill airspace you can measure

What landfill operators, solid waste authorities and their engineers fly drones for, how often and against which rules — and how Omniris turns those flights into remaining airspace, airspace consumed, grades, slopes, drainage and change you can measure, state the accuracy of and keep on record for the life of the site.

Summary

A landfill's permitted airspace is the asset it sells. Every ton accepted at the scale uses some of it, and every cubic yard saved by better compaction extends the site's life. Owners and regulators therefore want the same few numbers again and again: how much airspace is left below the permitted grades, how much was used since the last survey, how densely the waste was placed, whether anything sits above the permitted limits, and whether the slopes, drainage and cover are holding up. Those numbers come from topographic surveys, and drones have made those surveys cheap enough for operators to fly them with their own staff, in place of a once-a-year flyover by a full-sized aircraft [15].

Omniris is a drone operations platform: it gets flights flown, stitches them into maps and elevation models, measures them, compares them over time and keeps every result in a tamper-evident vault. For a landfill that means:

How landfills use drones today

Municipal solid waste (MSW) landfills in the United States operate under the federal criteria in 40 CFR Part 258 (often called Subtitle D), state permits that add their own design and reporting rules, and, for larger sites, the federal air rules for landfill gas. Almost every recurring drone mission at a landfill traces back to one of those requirements, or to the business of selling airspace.

The missions

Capacity, consumption and density

The method is simple arithmetic on two surveys. Survey the site, survey it again later, and the difference is the airspace used in between. Divide the waste tonnage from the scale house for the same period by that airspace and you have the in-place density, or the airspace utilization factor [14]. A draft report for a Benton County, Oregon, landfill capacity subcommittee shows the whole chain for one landfill: density derived from aerial flyover data (1,961 lb/yd³ in its 2021 operating year), airspace used for the year, airspace remaining, and a site-life estimate that moves by years depending on which density is assumed — information it says is "updated annually with aerial flyovers" [14]. Remaining airspace is the volume between today's surface and the permitted top-of-waste design, and the remaining life is that volume divided by the expected rate of filling.

The survey interval is the lever. Trade press describes operators replacing a once-a-year topographic survey flown by a full-sized aircraft with drone surveys flown by their own staff, who fly the whole site periodically to calculate the airspace used; knowing the waste placed between two surveys gives the density and shows whether working-face procedures need to change [15]. Regulators set the floor — often an annual report — and operators fly more often for their own reasons.

Cover, closure and post-closure

Subtitle D sets the cover rules. Daily cover is six inches of earth at the end of each operating day, or an approved alternative [1]. Final cover must have permeability no greater than 1 × 10⁻⁵ cm/s (or that of the bottom liner or natural subsoils, if lower), an infiltration layer of at least 18 in (46 cm) of earth and an erosion layer of at least 6 in (15 cm) that can sustain native plants, and closure must be certified — by an independent registered professional engineer or the approved state — when complete [5]. Then post-closure care runs for 30 years by default, and includes "making repairs to the cover as necessary to correct the effects of settlement, subsidence, erosion, or other events" [6]. States add geometry: Massachusetts, for example, requires a final top slope of not less than 5 % and side slopes no steeper than three horizontal to one vertical [13]. Run-on controls must handle the peak discharge of a 25-year storm, and run-off controls the water volume of a 24-hour, 25-year storm [3]. Records of inspections, monitoring and closure live in the facility's operating record [4]. Each of these is a question about surface shape, slope, water and change — exactly what repeat elevation surveys measure.

Landfill gas

Landfill gas is roughly half methane and half carbon dioxide, and MSW landfills were the third-largest source of human-related methane emissions in the United States in 2022, about 14.4 % [17]. Two different rules apply. Subtitle D limits methane to 25 % of the lower explosive limit in facility structures and to the lower explosive limit at the property boundary, monitored at least quarterly [2]. The federal air rules for larger landfills with gas collection require quarterly surface monitoring around the perimeter and along a pattern at 30 m intervals, with the probe 5 to 10 cm above the ground and 500 ppm above background counted as an exceedance, plus a program to monitor cover integrity monthly [7].

Drones are entering this work through gas sensors, not cameras. EPA's Other Test Method 51 describes an unmanned aircraft carrying a sampling line close to the surface as an alternative to the walking Method 21 survey for the surface methane standard under several federal landfill rules, though not for the Tier 4 provisions it lists [8]. A UK Environment Agency study of a downward-pointing laser methane sensor found the drone covered transects in about half the time of a two-person walkover, but the walkover located potential sources more precisely and the drone gave false positives linked to ground vegetation; the study found it a potentially good tool for identifying areas of emission, to be investigated further with a portable gas detector [9].

Fires and elevated temperatures

EPA distinguishes landfill fires, which usually occur at or near the surface where oxygen is available, from elevated-temperature landfills, where abnormal chemical reactions within the waste mass raise temperatures above regulatory thresholds — elevated gas temperatures above 131 °F (55 °C) at the wellhead are a common indicator — and cause "rapid and severe waste settlement", leachate outbreaks and odors; its examples list enhanced monitoring of landfill elevations among the responses [10]. Thermal drones are used to screen for surface hot spots. Washington's Department of Ecology flew one over three areas of a landfill with a confirmed underground fire and was candid about the limits: thermal imaging "may be affected by time of day, other sources of heat, type of surface material, light, and distance", and the images help confirm what is known and show where more data is needed [11].

Who flies, and what it replaced

• In-house. Some operators bring on their own staff pilots: a landfill manager obtains a drone pilot's license and flies the site periodically for elevation data to calculate the space used, with GPS on the compaction equipment filling in between flights [15].
• Consulting engineers and surveyors. State annual reports call for professional sign-off — Ohio's topographic map must be "certified by a professional skilled in the appropriate disciplines" [12] — so a surveyor or engineer is part of the work whoever flies the drone.
• Outside providers. Companies sell software services in which a drone flies the landfill on a programmed flight path and the photos are developed into surveys [15].

Before drones, the capacity survey was often contracted to a company flying a full-sized aircraft once a year [15]. One public authority quoted in the trade press put that annual aircraft survey at $6,000 and replaced it with a one-time $10,000 investment in a drone; another authority's facilities chief contrasts a map ready the day after an in-house flight with sending photos out to be developed into a CAD plan, which "could take weeks to months" [15].

Pain points

• Infrequent data. Where the topographic survey is flown once a year [15], months pass in which nobody knows how close the active area is to its permitted grades.
• Thin layers magnify error. A quarter's worth of waste can be a thin layer over a large area, so a small vertical offset between two surveys becomes a large volume (see the arithmetic under Accuracy and standards). Ground control and checkpoints decide whether a consumption number can be trusted.
• Data in pieces. Surveys, CAD designs, scale records, inspection notes and thermal images live in different systems, which makes the operating record hard to assemble and harder to defend [4].
• Long horizons. Post-closure care runs for decades [6]; the surveys that prove the cover was maintained need to stay findable and provably unaltered for as long.

Use case by use case: what Omniris does

The table takes the missions above one by one and says what Omniris delivers for each. The sections that follow walk through each workflow.

Remaining airspace and airspace consumed

Everything in this section starts from an ordinary mapping flight. Omniris stitches the photos into an orthomosaic and two elevation models — a surface model (DSM), the top of everything, and a terrain model (DTM), the modelled bare ground. The elevation models are made at 0.8–2 in (2–5 cm) per cell, set from the flight's photo resolution. Volumes are always computed on that full-resolution elevation model, cell by cell, never on a preview. The Stitching paper covers how the maps are made.

Remaining airspace: the survey against the permitted grades

In the map's Map Tools panel, choose Volume, draw a boundary — the permitted footprint, a cell, a phase — and choose Design surface as the base. The volume is then computed between your survey and the design, cell by cell:

• Fill is where the design is above today's surface: the airspace still available inside the boundary, up to that design.
• Cut is where today's surface is above the design: material above the permitted grades.
• Net, the area actually measured, and a ± uncertainty for each figure come with it. Where the boundary goes beyond the design's coverage, those cells are left out and the result says what percentage of the boundary that was. Cells with no elevation data (water, deep shadow) are excluded and reported the same way, and a figure above 2 % is flagged treat with caution.

Which design you use decides what the number means. A top-of-waste design gives airspace for waste; a top-of-final-cover design gives a figure that still includes the space the final cover will occupy. Omniris measures against exactly the surface you give it, so choose the design that matches the figure you report.

There are two ways to bring the permitted grades in:

Civil design surfaces stored inside a DWG (Civil 3D surfaces, corridors) cannot be read by the free readers Omniris uses; the import lists them by handle and says to export the terrain as LandXML and use it as a design surface. The Design and progress paper covers design models in full.

Measured on every flight, automatically

Save measurement turns the boundary and its settings — base, design, surface, material — into a named measurement. Attached to a Site Management site, it computes itself for every survey of the site that covers the whole boundary: the flights already there when you save it, and each new stitch as it finishes, usually within minutes. A flight that clips only part of the boundary is not used, and an automatic result is not recorded when more than 25 % of the boundary has no elevation data; the measurement says how many surveys were skipped and why. Editing the boundary or base recomputes the past results in the background, so the history never mixes two definitions; the tamper-evident custody record keeps the old and new value of each setting the edit changed, and each recomputed flight's volumes and tonnage before and after.

The site's Volumes section in the Site Navigator then lists each measurement with one line per flight date — value ± error, a no-data flag, tonnage where a density was set — and a Volume over time chart. The site's page in the Site Manager carries the same measurements with a printable report each and a spreadsheet of every result. Remaining airspace becomes a series you can read at a glance instead of a number produced once a year. The Site Management paper describes sites, the Site Navigator and automatic measurements in full.

Airspace consumed: one flight against another

Consumption is the difference between two surveys. There are two ways to get it:

• Compare epochs on a saved measurement: pick an earlier and a later survey and the surface change inside that boundary is computed directly.
• Compare in the Site Navigator (Difference mode): two dates and a surface model, over the whole survey, a site zone polygon, a saved measurement's boundary or an area you draw.

Both report material added (where the later surface is higher), material removed (where it is lower) and the net, each with a ± that carries the error of both surveys (the Compare card labels added and removed as cut and fill and says which is which). For an active cell, material added is the airspace consumed by waste, daily and intermediate cover and anything else placed in the period. Settlement in the same period shows up as material removed, so the net figure is consumption net of settlement; which one you report is your call, and both are on the page. Cells missing on either date are excluded and counted.

Every comparison carries a co-registration grade for how well the two surveys line up vertically, from their ground control and alignment records: green (RMSE within 1.6 ft (0.5 m)), amber (within 6.6 ft (2.0 m), or anchored with no RMSE recorded), red, or unaligned. An unaligned pair is still computed but labelled estimate grade on the numbers themselves, because an offset between two surveys reads as change. Comparing dates works between stitched surveys; the epoch pickers list stitches only.

Illustrative example values.

Compaction density and tonnage

In-place density is scale-house tonnage divided by the airspace it consumed. Omniris supplies the denominator — the airspace consumed between two surveys — and the record behind it. You bring the tonnage from your scale records and do the division in your own spreadsheet or reporting system, using the comparison's report or spreadsheet export; the same remaining-airspace figure divided by your fill rate gives the remaining life.

Illustrative example values. The division is done outside Omniris.

The volume tool can also work in the other direction, turning a volume into a weight. Enter a material density and every result shows tonnage beside the volume — in US short tons when your units are set to imperial. That is useful for cover-soil, clay and aggregate stockpiles and borrow areas. Two details matter for landfill work:

• Density is entered in lb/yd³. With imperial units the density box takes pounds per cubic yard and shows the metric value beside it — 1,200 lb/yd³ (0.71 t/m³); with metric units it takes t/m³. The value is stored in t/m³, so changing units never changes a saved measurement.
• The preset list is for earth materials. It holds nominal values for sand, gravel, crushed stone, topsoil, wet clay, riprap, asphalt millings, demolished concrete, coal and wood chips; for waste, type in your own measured density. A density you type yourself is tagged site-tested, a preset preset (nominal), and the tag travels with every tonnage figure so a reviewer can see where the weight came from. A material state (bank, loose or compacted) and a swell/shrink factor can be recorded with it.

Permitted grades, slopes and drainage

Grades, slopes and water are where a landfill's surface meets its permit: the top slope that sheds rain, the side slope that stays stable, the channels sized for the 25-year storm [3], the low spots that pond on a settling cap. Omniris's terrain analysis turns a flight's elevation model into the survey products those questions need. Open the stitch's terrain or surface model, click the mountain button, tick the products and press Run. It runs in the background at the model's full resolution, at no charge, and the results land in a folder beside the stitch and as layers in the Site Navigator.

Depressions fill to their lowest outlet, so a pond is the water a hollow would hold before it spills. Contours drawn on the surface model follow anything standing on the ground, so use the terrain model for ground contours. A surface too large for any available processing machine is offered at a coarser cell size, which Omniris names before anything runs and records on every file it makes.

The slope map shows every grade on the same scale, flight after flight. Read it and the click-to-read values against your permit's limits — a 3H:1V side slope reads 33.3 % grade — and use the volume tool's design comparison for grades against the approved design.

Elevation along a line

The Profile tool in Map Tools draws a cross-section of the ground along any line you draw — across a bench, down a letdown, through a cell — with distance and elevation on hover and min/max labels, sampled from the elevation model at up to 2,000 points along the line (a very long line over a very large model reads a coarser overview and is labelled approximate). Where there is no elevation data the line breaks rather than interpolating across the gap. Export CSV downloads the profile (in metres, so it re-imports unambiguously). The Distance tool gives a line's horizontal length, its slope distance (the straight 3D line between the points you place) and its length following the ground at 16 ft (5 m) resolution, and Area gives geodesic area and perimeter in acres or ft².

Stormwater basins and cover soil

The volume tool's other bases cover the rest of a landfill's earthworks. Highest point measures a basin or hollow below its rim; Custom elevation measures to a known outlet or floor elevation; Triangulated, the default, measures a stockpile over sloping ground. A stockpile of cover soil, clay for the cap or aggregate for roads is measured the same way, with tonnage from the density you enter, and saved on the site to be counted on every flight — the cover-soil inventory a state annual report may ask for [12].

Settlement and change between surveys

Settlement and subsidence are the reason a closed landfill is surveyed for decades [6], and sudden or uneven settlement is one of the signs EPA lists for elevated-temperature landfills [10]. A point survey of settlement monuments sees only the monuments; repeated drone surveys see the whole cap. Omniris offers three ways to watch it.

The change map

In the Site Navigator's Compare section, a Difference comparison of two surface models gives the numbers, and Show change layer bakes a difference map onto the site: red where the surface rose, blue where it dropped, zero at the neutral centre of the colour scale, intensity scaled to the size of the change. The map is saved as a normal file in the vault beside the later survey and appears as a layer of the site. Visual mode puts any two dates side by side with a fade, a swipe curtain or a blink comparator — useful for orthomosaics, where a computed colour difference would mostly measure the change in sunlight. Comparison results print as a report (PDF) or download as a CSV spreadsheet.

Change alerts

Any elevation comparison on a Site Management site can become a change alert: press Alert me and choose what to watch — net volume change, material added or material removed — and a threshold in cubic yards (the cubic-metre equivalent is shown as you type). Every six hours Omniris checks for a new flight of the site; when one has landed it compares it with the flight before, over the same area, and emails you if your measure reaches the threshold. The alert page then outlines and numbers the areas that changed, largest first, with their size in ft², average change in ft and volume in yd³, and whether the ground rose or fell.

• Only change the surveys can resolve. An area is outlined only where the change is more than three times the survey's ground resolution, more than twice the alignment error between the two surveys (1.6 ft (0.5 m) for an aligned pair with no error recorded) and more than any minimum height change you set, and only when it covers at least the minimum area — 100 ft² by default. Two surveys that are not aligned get no outlines.
• Straight to the work list. Each changed area can be promoted to a finding, or the alert can create findings automatically every time it fires. A later flight that sees the same change, in the same direction, adds to the open finding instead of opening a new one.
• Limits. Up to 25 active alerts per person and 5 per site; one email per alert at most every 12 hours; extra recipients must have Omniris accounts that can see the site. An alert that cannot run says why on its card, and pauses with an email after repeated failures rather than going quiet.

Saved measurements as a settlement record

A saved measurement over a closed cell, with a custom elevation or a design surface as its base, is measured on every new flight of the site. Its volume-over-time chart is a running record of how much the cap has dropped inside that boundary, with every point traceable to the flight and surface that produced it.

Cover, cap, erosion and hot spots

Cover defects as tracked findings

Cover integrity is mostly found by eye — erosion rills, cracks, exposed waste, stressed vegetation, seeps — and fixed by a crew. In Omniris each of those becomes a finding: a work item at a point or over an area drawn on the map, with a category, severity, status, a person responsible, evidence images and a complete history. Findings can be worked from the Omniris phone app on site, with or without signal, and are kept in the same custody record as the survey that showed them. The Findings paper describes the workflow.

Omniris has open-vocabulary AI object detection: you describe what to look for in plain words, review and correct what it finds, and promote results to findings. On a cover it is an aid to the person reviewing the imagery, not an inspection. Elevation change catches the defects that change the surface (a slump, a washout, a deep rill); a hairline crack does not register as elevation change.

Thermal screening for hot spots

A flight with a supported radiometric thermal camera (DJI enterprise thermal models; FLIR-based cameras only where validated, others are labelled unverified) is stitched into a temperature map in which every pixel is a measured surface temperature, °F first. On it you can click for a temperature, compare two points, get statistics inside an outline, highlight everything above a temperature you choose, and run anomaly detection: areas a set amount warmer than the flight's typical temperature (10 °F above it, at least 10 ft² (0.9 m²), by default; adjustable, and a cold mode too), ranked and located, with each promotable to a finding. The Thermal Imaging paper covers the camera support and tools.

Vegetation on the cap

Final cover includes an erosion layer that must sustain plant growth [5]. A flight with a multispectral camera gives vegetation index maps (NDVI and NDRE), and Compare's index mode reports how much area improved or declined between two flights (and, for NDVI and NDRE, the plant cover gained and lost), with a change layer showing where. The Multispectral paper describes it. Omniris reads plant vigour; it does not assess the cover's soil or its permeability.

Accuracy and standards

Two kinds of accuracy matter, and landfill numbers lean on both. Relative accuracy — how true the map is to itself — carries a single-flight volume such as a stockpile. Absolute accuracy — how true the map is to the world — carries everything a landfill reports most: remaining airspace against a design drawn in State Plane coordinates, and airspace consumed between two flights. A drone without RTK or ground control is only as good as its own satellite positioning; RTK or surveyed ground control is what ties the map to real coordinates at survey accuracy. Omniris measures against designs and earlier flights either way, but it tells you when the result rests on uncontrolled positions.

Illustrative arithmetic: a uniform vertical offset becomes volume in direct proportion to the area. This is why comparisons are graded for co-registration.

Ground control and checkpoints

• Ground control points (GCPs). Import surveyed coordinates from the files survey equipment produces (Emlid Reach, Trimble Access, Leica Captivate and others, or a plain CSV) in your survey's coordinate system — State Plane in US survey feet included. Heights in NAVD88 are converted with GEOID18 (GEOID12B in Alaska) before the stitch, on a site whose frame is NAD83(2011) and inside those grids' coverage. Mark each target in the photos — coded targets can be found automatically — and save the set as a GCP site to reuse on every re-flight, marking only the new photos. The stitch dialog's target is five points, each marked in five photos.
• Checkpoints. Surveyed targets left out of the fit and used only to measure it. When the stitch finishes, its card shows the measured accuracy as horizontal and vertical RMSE, feet first; the GCP results page adds 3D RMSE, the error east, north and up at every checkpoint and a tag on checkpoints outside the area the GCPs enclose. Checkpoints marked later are measured on the finished map with no re-stitch and no credits, and every measurement is kept.
• Accuracy class. A controlled stitch is labelled by the horizontal accuracy of its least accurate control point: survey-grade (every point stated to 4 in (0.1 m) or better), survey control (up to 3.3 ft (1 m)), or basemap-grade, which the results say not to certify as survey-grade.
• RTK and alignment. RTK flights are supported; each site states once which frame its corrections are in (WGS84/ITRF or NAD83(2011), for example), because the photos do not record it. A re-flight can also be aligned to an earlier stitch of the site, so the two line up for comparison without marking anything; it inherits the earlier flight's accuracy.

Published practice gives the frame for these numbers. The current ASPRS Positional Accuracy Standards (Edition 2, Version 2, 2024) report accuracy as RMSE alone, and Edition 2 raised the minimum number of checkpoints for a product accuracy assessment from 20 to 30 [16]. Omniris computes and reports the RMSE at whatever checkpoints you survey; it does not certify a map to an ASPRS class.

What the ± on a volume means

Every volume carries a ± computed from an error model published in the industry: a per-cell error that scales with the survey's resolution, summed over the cells that contributed. A comparison's ± carries the error of both surveys, so it is larger than a single flight's. The ± describes the quality of the surface at its resolution. It does not include a vertical offset between two surveys — that is what the co-registration grade reports — nor a boundary drawn in the wrong place, nor a design in the wrong coordinate system.

Heights and datums, named on every product

Contours, terrain products and CAD exports all state the vertical reference of their heights: orthometric heights (EGM96) for a stitch without RTK or control, ellipsoidal heights with their frame for RTK and for ground control (NAVD88 control is converted to NAD83(2011) ellipsoidal heights before the stitch, and the products say so rather than claiming NAVD88), or "heights relative — vertical datum unknown" when it cannot be established. The CAD export applies the shift from the drone's WGS84/ITRF frame to NAD83(2011) as of the capture date when you export in State Plane, and never shifts a stitch that was already controlled in NAD83.

Evidence and records

A landfill's numbers end up in front of regulators, auditors, financial-assurance reviewers, neighbours and sometimes courts. Subtitle D requires an operating record of inspections, gas monitoring, closure and post-closure monitoring [4], and post-closure care lasts 30 years by default [6]. Omniris keeps the surveys behind those numbers in a vault designed to show they have not changed:

• Custody from the first upload. Every photo and every stitched result — orthomosaic, elevation models, contours, terrain products, CAD exports, change maps — is recorded in a tamper-evident custody record with its SHA-256 fingerprint, linked to the job that made it. Every download, export and share is recorded too.
• Measurements and comparisons on the record. Each volume result and each comparison writes a custody entry naming the surveys it used, so a figure in a report can be traced back to the exact files that produced it. A design surface lives in the vault with its own custody, so the surface a remaining-airspace figure was measured against is part of its provenance.
• Reports with their provenance. A saved measurement's report prints the surface used, survey date, resolution, base method and design, boundary, no-data percentage, who computed it and when, the co-registration grade for comparisons, the volumes in yd³ and m³ with their ± — and the accuracy disclaimer.
• Certificates anyone can check. A signed custody certificate can be issued for a file and verified on a public page by someone with no Omniris account.
• Legal holds and retention. A hold on a site protects all of its imagery at once; a retention policy keeps records for as long as you set and disposes of them with a signed certificate when it ends. Held results are never overwritten: re-running a stitch over them keeps the old results and puts the new ones in a fresh folder.

The Evidence Integrity paper explains the custody record, certificates, holds and retention in full.

Getting the flights flown

Planning the survey

The Omniris mission planner lays out a grid over the area you draw (75 % forward and 70 % side overlap by default, camera straight down), works out photo count, resolution, flight lines, time and batteries for your camera, and exports the plan for DJI Pilot 2, DJI Fly, Litchi or QGroundControl, or as a boundary for apps that plan their own route. On a landfill the most useful option is terrain following: the ground under the flight rises from the toe of the slope to the top of the fill, and a flight at one altitude photographs the top in finer detail than the toe. The planner can hold a constant height above the ground using a worldwide terrain model or one of your own earlier stitches of the site, and says how much the resolution would vary across the area without it. It warns when a plan goes above 400 ft (122 m) above the ground. The Mission Planning paper covers it in full.

Airspace and pre-flight

Where a landfill is near an airport, airspace decides whether and how high the survey can be flown. The planner checks the whole route against FAA airspace data — including the floors of Class B, C, D and E airspace — and, where LAANC authorization is needed, works out what to file and records what was granted. A Part 107 pre-flight checklist that cannot skip its regulatory items, the flight log and the mission file are kept with the job, under the same custody record as the data.

Who flies

• Your own pilots. An organization's managers and pilots plan, fly, upload and stitch on the same sites; each finished stitch named for the site joins the site's earlier surveys in the Site Navigator.
• The Omniris marketplace (cloud and data center editions). Post a job with the area drawn on the map and the deliverables you need; approved pilots whose travel radius covers the site are notified, apply, or receive a direct offer from you, and deliver into the job's folder. A job can recur — weekly, every two weeks, monthly, quarterly or on a custom schedule — so a capacity survey is requested once and each occurrence appears on its own. Pilots' Part 107 certificates can be verified against the FAA's records. Marketplace payments run through the platform; commerce is not part of on-premises installations.

Integrations and delivery

Two exports are metric by design: the volume spreadsheet and the profile CSV are in SI units (m³, m), because a spreadsheet is data to be re-imported unambiguously; the on-screen numbers and the printed volume report show imperial units. Orion, the Omniris assistant, can also measure a volume inside a site polygon or saved boundary, compare a saved measurement between two flights, or draw an elevation profile when asked in plain words; it answers from the same calculations the tools use, and a measurement too large to compute in a chat turn is declined with a pointer to the volume tool rather than estimated. The Sharing and Delivery paper and the Orion paper cover these in full.

Cloud, data center and on-premises

Everything in this paper — stitching, volumes, design comparison, Compare, change alerts, terrain analysis, CAD export, checkpoints and the custody record — works the same way wherever Omniris runs:

A public authority that must keep its survey data on its own network can run on-premises and still use every measurement tool. An on-premises installation connected to the Omniris cloud can send an individual stitch there, chosen stitch by stitch, billed to the organization's cloud credits.

What the results are, and what they are not

Landfill figures end up in permits, financial assurance and court records, so the boundaries of what Omniris produces are stated where they apply:

• Measurements, not a certified survey. Omniris produces the measurements, their stated accuracy and their provenance. Annual capacity reports, closure certifications and post-closure inspection forms are prepared and signed by your engineer of record; a drone survey is not a certified survey.
• Gas monitoring is outside its scope. Methane and other gas measurement, surface emissions monitoring under Method 21 or OTM-51, explosive-gas probes and wellfield data stay with your gas monitoring program and contractor.
• Surface temperature is a screening signal. Thermal readings are of the surface only; they are not temperatures inside the waste or at a wellhead, and a hot spot is not a fire diagnosis until probes and gas measurements confirm it.
• Permit limits are yours to apply. Slope maps, cut/fill against the permitted design and volumes are measurements; whether they meet a permit is a determination for your engineer and your regulator.
• Comparisons rest on alignment. Two surveys that don't line up show their offset as change. Every comparison is graded for co-registration and labelled estimate grade when unaligned; fly with ground control or RTK, or align re-flights, when consumption numbers matter.
• A design is measured in its own coordinates and heights. What a design file does not declare (most DXFs declare only their drawing unit) is stated in the Volume tool and recorded with the measurement. Heights that cannot be converted reliably — a design in latitude and longitude, EGM96 heights on a NAD83 design, or a NAD83(2011) design in California whose epoch doesn't match the survey's control — are refused with the reason rather than measured on a guess.
• Elevations come from photos. Under dense vegetation a photo survey sees the plant tops; the terrain model filters what it can. The LiDAR paper describes the separate LiDAR products.

Sources

1. 40 CFR § 258.21, Cover material requirements. https://www.law.cornell.edu/cfr/text/40/258.21
2. 40 CFR § 258.23, Explosive gases control. https://www.law.cornell.edu/cfr/text/40/258.23
3. 40 CFR § 258.26, Run-on/run-off control systems. https://www.law.cornell.edu/cfr/text/40/258.26
4. 40 CFR § 258.29, Recordkeeping requirements. https://www.law.cornell.edu/cfr/text/40/258.29
5. 40 CFR § 258.60, Closure criteria. https://www.law.cornell.edu/cfr/text/40/258.60
6. 40 CFR § 258.61, Post-closure care requirements. https://www.law.cornell.edu/cfr/text/40/258.61
7. 40 CFR § 60.765 (NSPS Subpart XXX), Compliance provisions — surface methane monitoring and cover integrity. https://www.law.cornell.edu/cfr/text/40/60.765
8. U.S. EPA, Other Test Method 51 (OTM-51): UAS Application of Method 21 for Surface Emission Monitoring of Landfills, December 2022. https://www.epa.gov/system/files/documents/2022-12/OTM%2051-%20UAS%20Application%20of%20Method%2021%20for%20Surface%20Emission%20Monitoring%20of%20Landfills.pdf
9. UK Environment Agency, Drone flyover surveys for identifying methane emission sources at landfills: summary. https://www.gov.uk/government/publications/drone-flyover-surveys-for-identifying-methane-emission-sources-at-landfills/drone-flyover-surveys-for-identifying-methane-emission-sources-at-landfills-summary
10. U.S. EPA Office of Research and Development, When Does a Municipal Solid Waste Landfill become an Elevated Temperature Landfill (ETLF)? (fact sheet, EPA/600/R-21/285), February 2022. https://www.epa.gov/system/files/documents/2022-04/elevated-temperature-landfills-factsheet-1.pdf
11. Washington State Department of Ecology, How we're gathering new thermal data at the DTG-Anderson Landfill, October 2023. https://ecology.wa.gov/blog/october-2023/how-we-re-gathering-new-thermal-data-at-the-dtg-anderson-landfill
12. Ohio Administrative Code 3745-535-660, Annual report (Chapter 3745-535, Municipal Solid Waste Landfill Operations), effective June 15, 2024. https://codes.ohio.gov/ohio-administrative-code/rule-3745-535-660
13. 310 CMR 19.112 (Massachusetts), Landfill final cover systems. https://www.law.cornell.edu/regulations/massachusetts/310-CMR-19-112
14. Draft report additions for the Benton County, Oregon, landfill size, capacity and longevity subcommittee, December 12, 2022 (posted in the county's land-use record). https://cd.bentoncountyor.gov/wp-content/uploads/2023/12/gilbert_121222_draft_report_additions_12_-12-2022_.pdf
15. Waste360, Landfill operators invest in new tech to conserve airspace (Arlene Karidis), July 23, 2020. https://www.waste360.com/landfill/landfill-operators-invest-in-new-tech-to-conserve-airspace
16. American Society for Photogrammetry and Remote Sensing, ASPRS Positional Accuracy Standards for Digital Geospatial Data, Edition 2, Version 2 (2024). https://publicdocuments.asprs.org/PositionalAccuracyStd-Ed2-V2
17. U.S. EPA Landfill Methane Outreach Program, LMOP one-pager, April 2024. https://www.epa.gov/system/files/documents/2024-04/lmop_onepager.pdf

Glossary

Airspace

The permitted volume of a landfill available for waste and cover, between the liner and the permitted final grades. Not to be confused with the airspace aircraft fly in, which this paper calls FAA airspace where it matters.

Airspace utilization factor (AUF)

Tons of waste placed per cubic yard of airspace consumed; the same idea as in-place density, usually in tons/yd³ or lb/yd³.

Checkpoint

A surveyed target left out of a map's fit and used only to measure its accuracy.

Co-registration grade

Omniris's grade (green, amber, red or unaligned) for how well two surveys line up vertically, shown on every comparison.

Cut / fill

In a volume against a base or design: cut is material above it, fill is space below it. Against permitted grades, fill is the airspace left and cut is material above the permitted grades.

Design surface

An engineering surface — here, permitted grades — supplied as a GeoTIFF, DXF or LandXML file, or from an imported design model, and used as the base of a volume.

DSM / DTM

Surface model (top of everything) and terrain model (modelled bare ground), the two elevation models every mapping stitch produces.

GCP

Ground control point: a surveyed target marked in the photos to tie the map to real coordinates.

GSD

Ground sample distance: how much ground one pixel or elevation cell covers, set by flight height and camera.

LandXML

An open file format for civil engineering data; here, a triangulated surface (TIN).

LEL

Lower explosive limit: the lowest concentration of a gas in air that can ignite. Subtitle D sets methane limits as fractions of it [2].

MSW

Municipal solid waste.

RMSE

Root-mean-square error: the standard summary of how far measured positions are from surveyed ones.

SEM

Surface emissions monitoring: measuring methane just above the landfill surface along a set pattern.

State Plane

The State Plane Coordinate System: the official U.S. map grids, one or more zones per state, on NAD83, in each zone's legal unit.

Subtitle D

The common name for the federal MSW landfill criteria in 40 CFR Part 258.

TIN

Triangulated irregular network: a surface made of triangles joining surveyed points.