VEXRAD Technical Library
A technical resource for geoscientists, engineers, researchers and project teams evaluating Atomic Dielectric Resonance (ADR), Virtual Boreholes and pre-drill subsurface intelligence.
Start with the physics. Examine how the outputs are constructed. Review validation against independent ground truth. Then decide what the evidence can — and cannot — support.
Start with ValidationBrowse PublicationsUnderstand the measurement first.
ADR is VEXRAD’s surface-deployed coherent pulsed electromagnetic approach to subsurface characterisation. These resources explain the technology, measured responses and how ADR fits within the wider geophysical toolkit.
Atomic Dielectric Resonance
How ADR acquisition works, what is measured and how electromagnetic responses are processed and interpreted with depth.
Explore ADR Technology →Non-Invasive Subsurface Exploration
ADR in context with EM, ERT/resistivity, MT, seismic, gravity, magnetics and GPR — different measurements for different geological questions.
Compare Geophysical Methods →Technical FAQs
Answers to questions about ADR physics, depth, accuracy, Virtual Boreholes, validation and project suitability.
Explore Technical FAQs →The Virtual Borehole
A VEXRAD Virtual Borehole is a depth-referenced interpretation derived from surface-acquired ADR measurements at a selected location. It is intended to provide an additional subsurface evidence layer before physical drilling.
It is not core. It is not an assay. It is not a guarantee of permeability. It is a geophysical interpretation designed to be tested.
Explore Virtual BoreholesVirtual vs Physical Borehole
Understand the distinction between indirect pre-drill geophysical intelligence and direct geological ground truth.
Read comparison →Virtual Borehole vs Seismic
Different physical measurements can provide complementary constraints on subsurface interpretation.
Read comparison →Virtual Borehole vs MT
Compare ADR’s active transmitted EM approach with magnetotelluric resistivity investigation.
Read comparison →Prediction first. Ground truth second.
The value of a pre-drill technology depends on whether its predictions survive independent testing. VEXRAD’s validation framework separates what has been demonstrated from what remains a candidate interpretation.
VEXRAD Validation
Prediction → independent test → result → evidence classification. Includes the principles used to assess ADR claims.
Validation Framework →Technology to Reduce Exploration Drilling
Why reducing drilling is credible only when pre-drill predictions are recorded, tested and tied to actual exploration decisions.
Reduce Exploration Drilling →Blind & Pre-Drill Testing
Why prospective predictions are stronger evidence than retrospective pattern matching — and why misses matter.
How We Validate →Apply the measurement to a specific geological question.
Mineral Exploration
Pre-drill investigation of host lithology, boundaries, structures, alteration/mineralisation indicators and candidate target intervals.
Mineral Exploration Technology →Geothermal Exploration
Depth-resolved investigation of lithology, formation boundaries, structures and candidate reservoir intervals before expensive wells.
Geothermal Exploration Technology →Water Exploration
Investigation of geology, structures and subsurface electrical/dielectric responses relevant to groundwater targeting and aquifer characterisation.
Water Applications →Move from claims to comparisons.
The most useful VEXRAD case studies are those where ADR interpretations can be compared with independently obtained drilling, logging, assay or other subsurface information.
Charters Towers
Pre-drill mineral exploration evidence with subsequent drilling available for comparison.
Review Case Study →United Downs
Pre-drill ADR interpretation compared with a subsequent deep geothermal well.
Review Case Study →Denmark Onshore
Virtual Borehole work with independent borehole information used to test geological interpretation.
Review Case Study →Go deeper into the technical record.
Use the Publications archive for conference papers, technical studies and scientific material relating to ADR, electromagnetic subsurface investigation and VEXRAD’s legacy evidence base.
VEXRAD Publications
Technical and conference material for readers who want more detail than a case-study summary.
Browse Publications →Insights & Evidence
Case studies, evidence summaries and project examples organised around what was predicted, what was independently tested and what was observed.
Browse Evidence →What ADR cannot establish on its own.
Technical credibility requires boundaries. ADR is an indirect geophysical measurement and should not be represented as direct geological sampling.
No guaranteed assay grade
ADR does not replace laboratory assay or establish a compliant mineral resource.
No guaranteed geothermal flow
A candidate reservoir response does not establish permeability, connectivity, sustainable flow rate or well productivity.
No universal geology
Performance demonstrated in one geological environment should not automatically be transferred to another.
Interpretation is conditional
Lithology and target interpretations depend on the measured responses, calibration, geological model and available supporting evidence.
Ground truth still matters
Drilling, assays, logs, core, temperature, flow testing and other direct measurements remain essential where those answers are required.
Known nulls are evidence
Misses and negative results help define the limits of the method and should inform future survey design and confidence.
Technical topics for geoscientists and project teams
Could your project provide the next independent validation case?
Tell us the geological question, target depth, existing geophysics, available drilling or ground truth and what decision the additional information needs to support.
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