SENSOR MAPPING
This is TerraFlow Mobile with the sensor mapping capability: the same app, reading survey instruments. The instrument changes. The way we collect doesn't. How TerraFlow Mobile works · Supported instruments
Put a sensor on a person, know where every reading was taken, and be able to show you covered the ground. Ludlum radiation meters and Geonics conductivity meters, logged against GNSS position once a second, at the accuracy your receiver supports, thousands of points a day.
Every reading knows where it was taken The instrument's output is paired with its GNSS position at capture, with the fix quality and accuracy recorded. A reading without a trustworthy position isn't a survey result. It's a number.
Continuous coverage, not a line of samples One record a second is about one record per yard (metre) at walking pace. At survey height, consecutive detector footprints overlap, so a walk becomes coverage.
The highest reading stays on top Readings draw in order of value, not collection order. A hot spot logged early is never buried under the routine readings that came after it.
Results the same day Readings write to Data Engine and your ArcGIS as you collect. The office looks at the data while the technician is still scanning.
When position error is bigger than the footprint
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 (GPS.gov).
When the position error is bigger than the detection footprint, you haven't mapped an anomaly. You've mapped a probability cloud. Two operators can walk the same ground, both record it as covered, and leave a gap between them that neither can see.
With RTK, position error drops one to two orders of magnitude below the detector's field of view. The uncertainty left is what the detector could see. That's where the uncertainty belongs: a physics limit you can know and draw.
Coverage you can show, not just claim
Walking a grid isn't proving a grid. On most programs, the only record that ground was scanned is a track line and an operator's word.
TerraFlow records a footprint around every reading, sized to the detector's actual field of view. The crew 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. And someone else can check it.
Points, lines, polygons, and the report
Log readings at points, walk a line, or close a polygon around an area. Every geometry carries its readings and their positions.
Records go to Data Engine as the device syncs. They load into your GIS, and Shapefile and CSV exports are produced automatically, so the files for the client's report are already there.
We don't own your analysis.
Your method. Your thresholds. Your QA chain. Your GIS.
Our job is narrower: we record every reading with its position and the accuracy of that position, and a coverage record that shows what was scanned and what wasn't. A statistic computed over positions and coverage nobody can check looks rigorous and isn't.
The method, the thresholds and the conclusions stay yours.
A mixed fleet, one workflow
Your older Ludlum meters are on serial. Your newer ones are on Bluetooth. TerraFlow Mobile reads both, so a mixed fleet doesn't force a mixed workflow.
Radiation: Ludlum Model 2221 (serial, through a Bluetooth adaptor). Ludlum Model 3001 and 3003 (Bluetooth, single channel), and the rest of the 3000 series: 3000, 3003i, 3004, 3004i, 3007, 3007B, 3007i, 3007Bi, 3014, 3078, 3078i (Bluetooth). Terrain conductivity: Geonics EM31-MK2 and EM38-MK2. Positioning: Trimble R Series and Catalyst, and the other receivers on the supported instruments list. Can-Net or any NTRIP service.
The same app runs the locate crew's Radiodetection, Vivax-Metrotech and Rycom locators. On a site where one crew carries a 2221 one week and an EM31 the next, running two data systems is a choice, not a requirement.
Port Hope, with WSP
WSP is scanning the entire town of Port Hope, Ontario, property by property, mapping gamma impacts for the Port Hope Area Initiative. They've run TerraFlow on the program since 2021.
12 TerraFlow Mobile licences. Ludlum 2221 meters. Trimble R2 and R980 receivers with Can-Net corrections. One record a second, thousands of points a day, written straight to ArcGIS Online. The office reviews the data while it's being collected, so remediation on a property can start while the technician is still scanning.
"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
Also running it: a nuclear decommissioning program across three plants, on 40 licences, with a mixed fleet of Ludlum 2221 and 3001 meters on Trimble Catalyst. A reporting task that took an hour now takes ten minutes.
When nothing is allowed to leave the site
Some sites can't use cloud software because their security rules forbid it.
TerraFlow can run inside your own network: database, processing and reporting on your infrastructure, with field devices syncing to your servers, not ours. Fully isolated deployments, with no outside connection at all, are supported on a program basis and scoped per site. Start that conversation early, because the packaging and delivery are part of the engagement.
Many field data platforms are cloud-only. Ours isn't.
On-premises deployment · Data ownership
Remediation and verification programs Long programs where the value is the density and consistency of the record over years.
Radiation and geophysical survey teams Continuous logging against position, with the instrument's own output kept, not transcribed.
Secure and regulated sites Government, defence, nuclear and critical infrastructure sites where the cloud isn't an option.
Specifications
Capture: every reading the instrument sends is stored automatically with its position, time and the GNSS metadata the receiver reports, including accuracy and satellites. Point, line and polygon, with per-vertex detail. Text, dropdown and radio-button attributes. Photos. The user on every record.
Collection methods: sensor-driven (a reading arrives, the position is stored with it), a single point, timed points or lines, or points the user chooses one at a time.
Hardware: Ludlum and Geonics instruments and the GNSS receivers on the supported instruments list.
In the field: upload work areas and reference data before you go, and navigate back to any point.
Devices: Android and iOS. Custom Windows builds for fully isolated networks.
Workflows and setup: your asset types, attributes, dropdowns and conventions, configured by us and managed through the web admin. Unlimited attributes.
Offline: works with no connection. Syncs when one returns.
Export: CSV, KML, Shapefile, ArcGIS Online and Portal, and DXF configured to your block and line standards. Import: DXF, KML, ArcGIS Online and Portal.
Deployment: hosted in Microsoft Azure with a separate database per client, or on-premises as TerraFlow Enterprise.