Construction support
Drone survey in the USVI for active jobsites.
Topographic and as-built survey flown over live sites — earthwork quantities you can put in a pay application, progress surfaces your civil team can design against, and an accuracy report that shows the work. Delivered at 0.10 ft, tied to your project control, under a USVI-licensed surveyor of record.
What this covers
Six jobs on a live site.
Every one of these is a survey product a project manager orders because something on the schedule depends on it, not because the imagery looks good in a board pack.
The same flight usually feeds more than one of them. If the site also needs a dated visual record for change orders and owner reporting, that is a 360° job walkthrough, captured on the same mobilization rather than a second trip.
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Pre-construction topo
Existing ground before you break it. A base surface and contour set tied to your project control, so the earthwork model you build quantities from starts from measured ground rather than a plat drawn a decade ago.
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Earthwork quantities and cut/fill
Cut, fill, and net between any two surfaces — existing to design, or last month to this month. Delivered with the surfaces the numbers came from, so a quantity in a pay application can be checked rather than taken on faith.
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Progress topo
A dated surface at whatever interval the schedule needs. Month-over-month volumes, stockpile measurement, and a record of what the site actually looked like when the pay period closed.
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As-built verification
Constructed conditions compared against the design surface, with deviation reported where it costs money: subgrade and pad elevations, finished grade, slopes, and pavement. Catches the problem while it is still cheap to fix.
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Corridor and roadway survey
Long, narrow sites that are slow and expensive to walk. Roadway, utility, and drainage corridors captured in a single pass, delivered as the cross-sections and profiles your civil team already works from.
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Post-storm damage assessment
Documented, dated conditions after a named storm, for insurance, agency, and grant documentation, and for scoping the repair. Directly comparable against any earlier capture of the same site.
How we hold accuracy
0.10 ft is a measurement,
not a specification.
Accuracy on a drone survey is not a property of the aircraft. It is a property of the control set under it and of the check points you deliberately did not use to build the surface. Ours is measured on every job and reported alongside the data.
- RTK on the aircraft. The Skydio X10 flies an RTK-corrected position on every exposure, so the photogrammetric solution starts from a known camera position instead of inferring one from the imagery alone.
- Control set with GNSS or total station. Trimble GNSS rovers, or the Trimble S7 where canopy or multipath makes GNSS unreliable. Control is distributed across the site and through its vertical range, not clustered where the truck could park.
- Independent check points. Points surveyed to the same standard as the control, withheld from the solution, then compared against the finished surface. That comparison is the accuracy figure — not the processing software’s own internal residual.
- Your coordinate system, not ours. Delivered on the project’s horizontal and vertical datum, in the units the drawings use. If the job runs on a site calibration, we hold that calibration rather than handing back something that has to be re-projected.
- Reported, every time. The accuracy report ships with the deliverable. It states the residual at each check point in US survey feet, horizontally and vertically, so your engineer can accept the surface on evidence rather than on the headline figure.
Stockpile and quarry
Inventory, not progress.
Most of this page is written for someone measuring how far a job has got. This section is not. It is for an operator measuring what is actually on the ground, for accounting rather than for a schedule.
Stockpiles, aggregate, spoil, material yards and active quarry faces get measured for a different reason than a construction site does. The question is not what changed since last month. It is how much is there, on this date, in a form your accountant or your auditor can accept — and whether it reconciles against what the books say should be there.
The base surface is the whole argument. A volume on its own means nothing, because every volume is measured against something. The same pile is a different number over the original pad level, over the ground as it now sits, or over a prior capture. A volume figure delivered without the surface it was measured against cannot be audited, and it should not be accepted. Ours names it.
Repeat captures compare directly, because the control does not move. Once a control network is set on a yard, every subsequent capture is tied to the same points. That is what makes a month-over-month difference a real change in material rather than a difference between two surveys. It is also why the second and third captures on a site cost less than the first.
Where the pile stops is a judgment, and consistency beats precision. The toe of a stockpile is rarely a crisp line; it merges into the yard. For a single number that matters less than people expect. For reconciliation across periods it matters enormously, because a toe drawn differently between two captures produces a movement that never happened. We hold the toe definition constant across a series and state it.
We deliver volume, not tonnage. Converting cubic yards to tons needs a density factor, and that factor is yours or your lab’s — it varies by material, moisture and compaction, and inventing one would put a number in your accounts that we have no basis for. Give us the factor and it goes in the report; do not give us one and the report stays in volume.
The surfaces themselves are the same products described under aerial mapping, and the accuracy behind them is the control work set out above. Compliance and licensure for agency or audit purposes sits on the capabilities page.
What a volume report states
- Base surface
- Named explicitly — pad level, prior capture, or a stated design surface
- Capture date
- On the report, not only in the file name
- Volume
- Cut, fill and net against that base surface, in cubic yards
- The surfaces
- Delivered with the report, so the number can be recomputed rather than trusted
- Method and control
- How it was captured and what it was tied to, with the accuracy report
Construction layout and staking
Available, and worth being precise about how.
Construction layout and staking is a service we provide, but it does not run the way the aerial work does, and you should know that before it is on your schedule rather than after.
Layout and staking runs with survey crews mobilized from the mainland, working Trimble total stations. It has to be scheduled in advance and it is priced against that mobilization. It is not an on-demand local call-out, and we will not describe it as one: if you need stakes in the ground tomorrow morning, we are not the answer to that particular problem.
What scheduling it does buy you is continuity. The layout is set to the same control and the same coordinate system the drone survey was tied to, so the staked points and the delivered surface agree with each other by construction rather than by coincidence. Where a job needs both, running them off one control network removes an entire category of argument about whose number is right. Equipment and licensure detail sits on the capabilities page.
What a staking mobilization involves
- Lead time
- Agreed at proposal, never on call
- Crew
- Survey crew mobilized from the mainland
- Instruments
- Trimble S7 robotic total station, Trimble GNSS rovers
- Ties to
- The control network and coordinate system your drone survey already runs on
Deliverables
Not footage. Something your engineers can work from.
Formats your team already opens, so the data goes straight into design, scheduling and reporting instead of sitting on a drive. Nothing here needs a proprietary viewer or a login to our portal.
| Deliverable | Format | Typical use |
|---|---|---|
| Point cloud | LAS / LAZ | The source measurement. Keep it and your civil team can re-cut a surface later against a different breakline set without paying to refly the site. |
| Surface | DWG (Civil 3D) / LandXML | Drops in as a TIN surface. Volume computations, corridor design, and grading run directly against it. |
| Contours | DWG / DXF | Plan-set backgrounds at your stated interval. Delivered on your layer naming if you send a template with the scope. |
| Orthomosaic | GeoTIFF | Scaled, georeferenced site background. Measure distances and areas off it, or drop it under a design in Civil 3D or QGIS. |
| Volume report | Cut, fill, and net between the two named surfaces, each with its capture date. What gets attached to a pay application or a disputed quantity. | |
| Accuracy report | Residual at every independent check point, horizontal and vertical, in US survey feet. The document that answers “how do you know.” |
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Photograph reserved — 1200×900 A ground control point set on a benched hillside lot, before cut
Control set with a Trimble GNSS rover before earthwork begins. The check points that verify the finished surface go in at the same time and are deliberately withheld from the photogrammetric solution. -
Photograph reserved — 1200×900 A delivered Civil 3D surface on screen, beside the ground it came from
The deliverable rather than the flight: a TIN attached in Civil 3D on the project coordinate system, with the grading model already running against it.
If the orthomosaic, surface, and contour products are the whole job and there is no earthwork question behind them, that is aerial mapping and it is scoped differently. If what you need modelled is the building rather than the ground, see scan to BIM.
Where we work
Each island is a different survey problem.
Terrain, access, and airspace change what a flight plan has to look like. We plan for the island the job is actually on.
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St. Thomas
Steep hillside benches and retaining structures, dense Charlotte Amalie building stock, and Class D airspace around Cyril E. King that has to be coordinated before a flight rather than during one.
Construction survey on St. Thomas → -
St. Croix
The territory’s large-parcel work: open agricultural topography, the industrial south shore, and long roadway and utility corridors where one corridor flight replaces days of walking.
Construction survey on St. Croix → -
St. John
National Park adjacency shapes the flight plan before anything else does, and steep private-road access decides how the ground control gets set at all.
Construction survey on St. John →
Questions we get
Before you send the parcel.
How accurate is a drone survey?
0.10 ft horizontal and vertical, stated in US survey feet, on well-controlled sites, and verified against independent check points that were withheld from the photogrammetric solution. Every deliverable ships with an accuracy report showing the residuals at each check point, horizontally and vertically.
An accuracy figure quoted without a check point comparison behind it is a specification, not a measurement. Ask any surveyor for the residuals, not the number.
Is the survey signed by a licensed surveyor?
Yes. Survey deliverables are reviewed and signed by a USVI-licensed surveyor of record. That is the difference between a survey and a folder of drone output, and it is what lets the work stand up in a permit submission or a quantity dispute.
Licensure and compliance detail is on the capabilities page.
How fast is turnaround?
48 hours from flight to deliverable is typical. The fixed-fee proposal comes back faster, usually within one business day of the scoping call.
Long corridors, multi-day captures, and jobs needing airspace authorization take longer, and the proposal states the delivery date rather than leaving it open.
What about tree cover and dense vegetation?
Photogrammetry measures the surface it can see. Under closed canopy it sees the canopy, not the ground, and any surface built from it will read high.
On a site with heavy bush we set control and collect ground shots with GNSS rovers or the Trimble S7 through the gaps, and the deliverable states which areas are photogrammetric surface and which are ground-surveyed. Where canopy is genuinely continuous, terrestrial scanning or a conventional ground crew is the honest answer, and we say so in the proposal rather than hand over a surface that reads as ground and is not. Terrestrial scanning is covered under scan to BIM.
Do you handle FAA authorization near the airports?
Yes. We operate under FAA Part 107 and coordinate airspace authorization before a flight goes on the schedule, not after.
Cyril E. King (TIST) on St. Thomas and Henry E. Rohlsen (TISX) on St. Croix both sit under controlled airspace, and a job inside it needs authorization in hand rather than applied for. Tell us the parcel at the scoping call and the airspace question is answered in the proposal.
Tell us about the site.
Send the island, the parcel, and what you need out the other end. We’ll come back with a scoped, fixed-fee proposal within one business day.