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Land survey & UXO

Find out what's in the ground before you build on it.

Unexploded ordnance delays construction, energy and farming projects across Europe. Drone magnetometry maps buried iron and steel across a whole site without anyone walking on suspect ground, so the clearance team digs where the data points, not everywhere.

Discuss your site

Who we work with

  • Infrastructure and road developers
  • Wind and solar contractors
  • Land reclamation and agricultural projects
  • Environmental and planning consultants
Common questions

What project teams ask us

If one of these sounds familiar, the answer below is where we would start.

Planning

“Does our site need a UXO survey before construction?”

If the site lies in a former conflict zone, near historical military installations or training areas, or the planning authority or insurer has asked for it, the answer is usually yes. A desk study of historical records gives the first indication; a survey confirms what is actually in the ground.

Doing it before ground works start is far cheaper than stopping a site after an excavator finds something.

What we do

  • Review historical and site information to assess the likely risk
  • Recommend whether a survey is needed and what kind
  • Plan the survey around your construction programme
Method

“A walkover survey is too slow and too risky for this area.”

Hand-held magnetometer surveys put operators on the ground they are checking and cover a few hectares per team per day. A drone flies the same sensor principle one to three metres above the surface, keeps people off the area, and covers large sites in a fraction of the time.

Walkover work still has its place in woodland, steep ground and for close-in checks. Most large projects combine the two.

What we do

  • Choose the right method for each part of the site
  • Plan terrain-following flights with RTK positioning
  • Coordinate with your EOD contractor on line spacing and detection targets
Capability

“What can drone magnetometry detect, and what can't it?”

Magnetometers detect ferrous metal: shells, bombs, mines with steel parts, and also pipes, cables, fences and scrap. They cannot detect non-ferrous or plastic-bodied objects, and they cannot tell a shell from a buried steel post. That is why every target needs physical investigation.

Detection depth depends on the object's mass and the flight height. Large objects can be found several metres down; small ones only near the surface. We state the detection threshold for every survey, so you know exactly what the result covers.

What we do

  • Agree detection targets and thresholds before flying
  • Choose fluxgate or caesium sensors to suit the targets and site
  • Report what the survey can and cannot rule out
Output

“What does our clearance contractor need from the survey?”

A clearance team needs a ranked list of targets with precise coordinates, an estimate of depth and size for each, and maps they can load into their own GPS and GIS tools. They also need to know the survey's coverage and detection threshold, so they can see which areas are clear and which need further work.

What we deliver

  • Magnetic anomaly maps as GeoTIFF
  • Target lists with coordinates, estimated depth and mass (CSV, Shapefile, DXF)
  • A survey report with coverage, data quality and detection limits
Survey process

From desk study to target list

  1. Desk study

    Historical records, site constraints, buried services and airspace.

  2. Flight planning

    Terrain model, line spacing, flight height and permits.

  3. Data acquisition

    Low-altitude magnetometer flights with RTK base station and magnetic base reference.

  4. Processing & hand-off

    Filtering, anomaly picking, depth and mass estimates, and delivery to the clearance team.

Magnetometry does not replace physical clearance. Every target is investigated by a certified explosive ordnance disposal team working to national requirements and the International Mine Action Standards (IMAS).

Reference

UXO survey methods compared

Each method suits different ground. Large sites often use more than one.

Hand-held walkoverVehicle-towed arrayDrone magnetometry
Coverage speedSlowFast on suitable groundFast
Risk to peopleOperators on suspect groundVehicle and driver on suspect groundNo one on the survey area
TerrainAlmost any, including woodlandFlat, firm, open ground onlyOpen ground, wetland, crops, rough terrain; limited under trees
Sensitivity to small objectsHigh (sensor close to ground)HighGood at low altitude; falls with height
Best useSmall areas, woodland, close checksLarge flat sitesLarge or inaccessible sites, first-pass mapping
FAQ

UXO survey questions

Does a drone survey replace UXO clearance?

No. A magnetometer survey shows where buried ferrous objects are likely to be. Only a certified explosive ordnance disposal team can investigate a target, identify it and make it safe. The survey makes clearance faster and cheaper by telling the team where to dig and where the ground is clear of significant anomalies.

How deep can drone magnetometry detect objects?

Detection depth depends mainly on the object's mass and the sensor's height above it. Large items such as aircraft bombs can be detected several metres down, while small items such as grenades are only detectable near the surface. Every survey report should state the detection threshold achieved on that site.

What weather and terrain conditions limit a drone survey?

Strong wind, heavy rain and dense tree cover limit low-altitude flight. Open fields, meadows, cleared construction sites and shallow water margins are ideal. Sites with power lines, steel structures or buried services produce magnetic interference that must be accounted for in planning and processing.

Have a site with a UXO question?

Send us the location, approximate area and your construction timeline. We'll tell you what kind of survey makes sense.

Book a free call Reply within two business days