RADIATION SURVEY SOFTWARE
Put a sensor on a person, know exactly where every reading came from, and be able to show you covered the ground. TerraFlow reads your Ludlum meter, stamps every reading with its GNSS position, at the accuracy your receiver supports, and writes it to your GIS while the technician is still walking.
We aren't a radiation company.
We're a positioning and field-data company that radiation people started calling. Their problem turned out to be a positioning problem.
Your meter tells you how much. TerraFlow records exactly where. Everything on this page follows from that.
The gamma walkover survey, and where it goes wrong
A survey-height detector sees a patch of ground about a metre (3 ft) across. GPS.gov puts a smartphone at about 4.9 m (16 ft) under open sky, and it's worse under canopy (GPS.gov). SBAS corrections such as WAAS typically bring that to 1 to 2 metres (3 to 7 ft) (FAA WAAS performance reports).
When the position error is bigger than the detection footprint, you haven't mapped an anomaly. You've mapped a probability cloud. Three things follow:
- Gaps nobody can see. Two operators walk the same ground, both record "covered", and leave a strip between them.
- Coverage nobody can check. The only record that ground was scanned is a track line and an operator's word.
- Surveys nobody can repeat. An elevated reading that can't be stood on again next week can't be characterised, or defended years later.
With RTK, position error falls one to two orders of magnitude below the detector's field of view, per the receiver manufacturer's specification. The uncertainty left is what the detector could see: a physics limit, and the right place for the uncertainty to be.
Coverage you can show
TerraFlow draws a footprint around every reading, sized to your detector's field of view. The technician watches coverage build on screen as they walk. The footprints export as real polygons, each carrying its reading's values.
Join them up and you have a coverage map: this ground was scanned, at this footprint, on this date, by this operator. A third party can check it.
Walking a grid isn't proving a grid. This is a record someone else can check.
At one record a second, a walking technician logs about one reading per metre (3 ft), so consecutive footprints overlap and a walk becomes continuous coverage. Readings draw highest on top, so a hot spot logged early is never hidden under the routine readings that came after.
Your meters, serial or Bluetooth
| Meter | Connection |
|---|---|
| Ludlum Model 2221 | Serial, through any Bluetooth serial adaptor (Bluetronium is the most used) |
| Ludlum Model 3001 | Bluetooth |
| Ludlum Model 3003 | Bluetooth |
| Ludlum Models 3000, 3003i, 3004, 3004i, 3007, 3007B, 3007i, 3007Bi, 3014, 3078, 3078i | Bluetooth |
| Geonics EM31-MK2, EM38-MK2 | Bluetooth |
Your older meters are on serial. Your newer ones are on Bluetooth. We read both, so a mixed fleet doesn't force a mixed workflow.
We don't own your analysis.
Your method. Your thresholds. Your QA chain. Your GIS.
What we do is record every reading with its position and the accuracy of that position, and show what ground was covered. A z-score computed over positions and coverage nobody can check looks rigorous and isn't.
The office sees it while the technician is still scanning.
TerraFlow works offline first and syncs as soon as it can. Readings write to ArcGIS Online without anyone touching them. At Port Hope, office staff review results while the technician is still on the property, and remediation can start before the scan is finished.
From the walk to the report
Readings can be points, lines or polygons. Every one carries its position and the accuracy of that position.
As the device syncs, records load into your GIS and Data Engine produces Shapefile and CSV exports automatically. The files your report needs are already there.
The ground it sits on
Contamination follows infrastructure. Trench backfill is more permeable than the ground around it, and buried services carry contamination along their length. A linear gamma anomaly that follows a trench line is often a mechanism, not a coincidence.
The same app runs the locate crew's Radiodetection, Vivax-Metrotech and Rycom locators, in the same coordinate frame. So the gamma survey and the buried services line up because of how they were collected, not because someone aligned them afterwards. And before any soil comes out, the crew has the locate record for what's underneath, with the locator's depth readings as the instrument reported them. It supports the one-call locate. It doesn't replace it.
Customers
WSP, Port Hope Area Initiative. Scanning the entire town property by property. 12 licences, Ludlum 2221, Trimble R2 and R980 receivers with Can-Net, one record a second, thousands of points a day. TerraFlow at Port Hope since 2015, WSP on TerraFlow Mobile since 2021.
"Terraflow has been instrumental in getting our Remediation Verification program off the ground and managing the mass of data that is collected on an ongoing basis. We typically collect thousands of data points per day. Terraflow has allowed us to upload this data expediently and allow us to review results and make decisions in near real time. We could not execute the work required without the software and support." John DeWilde, MEng, PEng, QP, Senior Environmental Engineer / Team Lead, WSP
A nuclear decommissioning program, across three plants, on 40 licences, with Ludlum 2221 and 3001 meters on Trimble Catalyst. A reporting task that took an hour now takes ten minutes.
Sites where nothing leaves the network
TerraFlow can run inside your own network, with field devices syncing to your servers. Fully isolated deployments are supported on a program basis and scoped per site.