How scan data is stored, archived and retrieved
Raw scan data is a permanent record of conditions at the time of survey. Here is how Corvus stores, archives, and makes data available — and why it matters years after the survey is done.
When a survey is finished, most people’s attention moves to the report. The report answers the immediate question, the drilling or the design proceeds, and the job moves on. But the raw scan data behind that report is something more durable: it is a permanent record of the conditions at the time of the survey, and there is no way to recreate it later. The structure will be drilled, altered, or covered over; the scan is the only record of what it was. How that data is stored, archived, and retrieved therefore matters long after the survey is done. Here is how it works and why it is worth caring about.
Raw data is not the same as the report
It is worth being clear about what scan data actually is. A GPR survey produces raw radar files. A LiDAR survey produces raw scans that are registered into a point cloud. These raw datasets are the measurements. The report — the depths, the markup, the interpretation, the drawings — is derived from them.
That distinction matters because the report only ever contains the answers to the questions asked at the time. The raw data contains far more. A GPR file holds reflections the surveyor did not need to interpret for that brief; a point cloud holds the geometry of every surface in view, not just the elements the drawings called for. If a new question arises later, the raw data can often answer it. The report cannot, because it was never asked.
Why long-term storage matters
The value of a scan archive is that it cannot be reproduced. Once a slab is drilled, a wall is opened, or a building is altered, the pre-works condition is gone. The only surviving record is the data captured before the change.
That has real consequences years down the line:
- Disputes and claims. When a question arises about what was inside a structure, or what condition it was in, an archived scan is direct evidence rather than recollection.
- Future works. A later project on the same structure can draw on an existing scan rather than commissioning a fresh one — provided the structure has not changed materially.
- Verification. An owner can check whether something has moved, cracked, or deteriorated by comparing a current survey against an archived baseline.
- Continuity. People move on and memories fade. A properly archived dataset outlasts the individuals who captured it.
A scan that exists but cannot be found is, for practical purposes, no scan at all. Storage and archiving are not housekeeping — they are part of the deliverable.
How the data is stored
Sound practice treats scan data as a managed record from the moment it is captured. Raw files are downloaded from the instruments and stored against the project, with a clear and consistent reference linking the data to the job, the date, the site, and the element surveyed. The data is held alongside the metadata that makes it usable later — the survey date, the equipment used, the calibration record, the coordinate system or local datum, and the surveyor’s notes.
Backup is fundamental. Data held in a single location is one failure away from being lost, so it is held with redundancy, in more than one place, so that no single hardware fault or accident destroys the record. The point cloud or raw radar file is the authoritative source, and it is protected as such. Derived outputs — reports, drawings, models — are stored with it, but they are understood to be products of the raw data, not replacements for it.
How it is retrieved
The test of an archive is whether the data can be found and used when it is needed, sometimes years later and often by someone who was not involved in the original survey. That depends on consistent referencing and on the metadata being kept with the data. A point cloud retrieved without its coordinate system, or a radar file retrieved without its calibration record, is far less useful than one retrieved complete.
When a client asks for data from a past survey, the practical questions are simple: can the right dataset be identified, is it complete with its metadata, and can it be delivered in a format the client can still open. Open, vendor-neutral formats help here — a point cloud held in an open format such as E57 will remain readable far longer than one tied to a single piece of software. Part of good archiving is choosing formats with that longevity in mind.
What to ask when commissioning
If the long-term record matters to your project — and on most structures it does — it is reasonable to ask a few questions at the commissioning stage. Ask whether the raw data is retained as well as the report, and for how long. Ask how it is backed up. Ask in what formats it is held, and whether you can request a copy of the raw data, not only the report, so that you hold the record yourself if you wish to.
A survey is a one-off capture of a structure at a single moment. The report serves the immediate need, but the raw data is the lasting asset. Stored properly, referenced clearly, and kept retrievable, it remains useful for as long as the structure stands.