Geophysical software & survey instruments

See what
the earth hides.

TERRA — earth. SCRY — to discern what is hidden.TERRASCRY: seeing what the earth hides.

Geophysical instruments and survey software

Graves, unexploded ordnance (UXO), wreckage, and buried structures can leave little to see at the surface. TERRASCRY pairs magnetic and electrical survey instruments with software to help follow those traces underground.

Explore the survey workflow Request a briefing
The survey, in contextInterface preview
Interface preview with example survey paths and modeled anomalies over riverbank imagery.
Survey paths, readings, and site imagery. Interface preview · example data.

Our mission

What we’re
looking for.

A search might start with an old map, a witness account, or a signal that stands out from the surrounding ground. Geophysical surveys add another way to read the site and choose where to look next.

01Burial sites

Graves and disturbed ground.

A grave shaft can leave a contrast between backfilled soil and the ground around it. Mapping that disturbance helps focus the search for a burial site.

02UXO discovery

Unexploded ordnance.

Buried ordnance can sit among scrap and other debris. Magnetic and electrical readings help map metal responses for investigation by UXO specialists.

03Crash sites

Aircraft wreckage and debris.

An aircraft can leave fragments scattered well beyond the impact point. The pattern of buried metal helps trace the extent of a crash site.

04Buried structures

Trenches, pits, and filled craters.

A filled trench or crater can disappear from view while its outline remains in the soil. Differences in the fill offer clues to what was there before.

What shows in a survey depends on the material, depth, and surrounding ground. Readings guide further investigation; confirming remains or identifying and clearing ordnance takes specialist work.

Survey workflow

From a surface survey
to a closer investigation.

Start with the site records and a surface survey. Compare the readings, mark areas of interest, and choose the next step. A HIRT probe grid offers a closer investigation where the site calls for it.

  1. 01Screen the surfacePathfinder
  2. 02Investigate a selected volumeHIRT · optional follow-up
  3. 03Compare and interpretTERRASCRY

01 · Pathfinder

On foot or by drone.
Follow the survey lines.

Walk a route with Pathfinder or carry its magnetic sensors beneath a drone. The readings trace changes in the magnetic field along each survey line. In the handheld setup, electromagnetic coils also measure conductivity, including responses from metals that a magnetic survey can miss.

  1. Cover the area. Record the instrument’s position as measurements are collected along survey lines.
  2. Look for contrasts. Compare magnetic and conductivity responses with the surrounding ground.
  3. Select follow-up areas. Review unusual responses alongside site records and terrain before planning closer investigation.
Inspect Pathfinder hardware
Surface surveySurvey diagram
Pathfinder surface survey lines and areas for follow-upSurvey lines cross an area, with symbols for a walking survey and a drone survey. Two illustrative response concentrations stand out from the surrounding ground; one is outlined as an area for closer investigation. They are not identified objects.
Survey route Response concentrationSurvey lines can be walked or flown. The outlined area marks a response worth a closer look.

02 · HIRT

A probe grid.
Measurements between probes.

HIRT means Hybrid Inductive-Resistivity Tomography. Coils and electrodes sit at known depths on probes arranged across a grid. Taking readings between different probes gives several views through the same ground, which helps build a three-dimensional model.

  1. Lay out the grid. Choose probe positions to cover the area of interest and suit the ground conditions.
  2. Take readings across the grid. Use induction and resistivity to examine different properties of the same ground.
  3. Build a model. Compare readings from many probe combinations to estimate where the ground changes and how far those changes extend.

Probe spacing and depth depend on the site. Suspected hazardous ground requires specialist assessment and clearance before insertion.

Inspect HIRT hardware
Probe-grid investigationSurvey diagram
HIRT probe grid and subsurface investigation volumeNine illustrative vertical probes form a surface grid and extend into a subsurface volume. Surface electronics connect the probes. Shaded regions represent a conceptual sensing relationship across the volume, not computed sensitivity or straight-ray paths. TXRX ABMN

Induction · coilsA transmitting coil produces a changing magnetic field. Receiving coils measure the response, providing information about conductive materials between and around the probes.

Probes Illustrative property contrastIllustrative grid and sensing regions; spacing and coverage vary by survey.

03 · TERRASCRY software

Turn measurements
into an interpretation.

Follow a response from its place on the map into a cross-section or 3D view. Compare it with nearby readings, terrain, and site records. The measurements stay separate from the model, so you can examine the evidence behind an interpretation.

Explore the software

Survey instruments

Hardware for surface
and probe-grid surveys.

Pathfinder surveys on foot or by drone. HIRT takes measurements between probes placed around an area of interest. Each gives a different view of what lies below.

CAD render of the complete Pathfinder handheld assembly, showing its frame, controls, and three sensor stations.
Pathfinder handheld assembly · CAD render
P / 01Surface survey

Pathfinder

Ground and drone surveying

Magnetic sensors can be carried on foot or beneath a drone. The handheld assembly shown here also pairs them with electromagnetic coils for conductivity readings.

Survey use Walk or fly survey lines and map areas that warrant a closer look.

Discuss Pathfinder
Enlarged CAD cutaway of the HIRT sensor module, showing its housing and internal sensing components.CAD render of the complete HIRT probe string with tip, rod sections, two sensor bodies, and cable-exit cap.
HIRT sensor cutaway and probe assembly · CAD rendersSensor detail enlarged.
H / 02Probe grid

HIRT

Crosshole subsurface imaging

Coils and electrodes sit at known positions along each probe. Readings taken across the grid help build a three-dimensional model of the ground between them.

Survey use Investigate the shape and extent of a feature within a probe grid.

Discuss HIRT

Ask us about instrument specifications and the survey you have in mind.

TERRASCRY software

Readings and models
in one view.

A signal makes more sense when you can see where it was recorded. Put survey readings beside terrain, aerial imagery, and site records, then examine the ground in 3D.

Interface preview showing terrain, a subsurface model, and a linked cross-section with example data.
Terrain, subsurface model, and cross-section · interface preview with example data.

Map, 3D & cross-section

Inspect the same site
from multiple views.

Move between the map, a 3D view, and a cross-section. Compare terrain and imagery with recorded readings and modeled results.

  • Keep source measurements distinct from model outputs
  • Inspect layers, depth bands, and selected features
  • Retain notes and the context behind an interpretation

Site preparation

Start with what’s
already known.

An earlier survey, an aerial photograph, or a marked-up map may explain a feature before anyone takes another reading. Keep those sources beside the measurements and see where the gaps remain.

Interface preview showing site imagery, source layers, and survey coverage with example data.
Site imagery and source coverage · interface preview with example data.

Government, universities & institutions

Tell us about
your site.

Whether you’re working on a burial site, surveying former conflict ground, or studying a buried feature, the first conversation is about the question your team needs to answer.

Field surveys

Tell us about the site, the ground conditions, and what you need to find. We can discuss which measurements would help answer the question.

Product inquiries

Ask about Pathfinder, HIRT, or TERRASCRY software, including specifications and your team’s purchasing requirements.

Research collaboration

Bring a dataset, a field study, or a measurement problem. Let’s discuss the work and what we could learn from it.

Request a technical briefing

Product & partnership inquiries

What are you
looking for?

Tell us what you know about the site and what you hope to find. We’ll talk through the instruments, software, and measurements that fit the work.

Contact TERRASCRY