Once in a lifetime a technology comes
along that changes everything.

Our scanner works with a unique combination of physics, mathematics and technical innovation.

Dr Colin Stove, the founder and inspiration behind the Adrok ADR Scanner, had a distinguished career in the field of radar – working with radar sensors from both satellites and the Space Shuttle, as well as working extensively with ground penetrating radar.

This fundamental understanding of wave and light physics gave him the insight and knowledge he needed to successfully reinvent the subsurface scanner using an advanced ‘coherent’ beam (two waves working together), that has worked so effectively, it is fundamentally changing the way the exploration industry works.

Why Atomic Dielectric Resonance?

The first three letters of our name A. D. R. stand for ‘Atomic Dielectric Resonance’. And this phrase is the key to how the scanner works. This is what we create and what we interpret. We measure ‘dielectric resonance’, which is the unique way materials resonate when hit by electromagnetic waves.

How does the scanner do what other scanners can’t?

The Adrok scanner transmits and then receives back, narrow pulsed beams of micro and radio waves. When these waves cross a boundary between material types, an ‘echo’ is reflected back to the scanner.

But the ‘echo’ that is received is different to the one that was sent out. It has a slightly different resonance. Why? Because a material has its own Dielectric Permittivity – or ‘resistance’ to the electromagnetic wave that we hit it with - think of it like pouring water on a variety of household objects - all will absorb and repel the water in a different and unique way depending on what it is made of.

This ‘echo’ is as unique as a fingerprint, and can then be analyzed to reveal detailed information on the characteristics of the material that has been discovered.

Because the micro and radio waves are both absorbed and reflected by materials, we can also obtain accurate measurements of the shape and depth of the materials scanned (effectively a map).

Download our ADR Technical White Paper for more information

Some frequently asked questions about our technologies?

Q: Do we emit a narrow beam as a laser?

A: No, as our deeply penetrating centre frequency has a wavelength of about 30metres the narrowest possible beam would be about 10 times wider than the wavelength because of Huygens' principle. However we do use beam modelling (a form of raytracing) in our analysis and some forward models.

Q: With a wavelength of 30m don't we have an error of 30m in feature localization?

A: This is true if we used a single photon. If N photons are used the theoretical error is 30m/sqrt(N). Classically we use phase information to accurately locate a reflector. In practice accuracy is limited by sampling rate, and not the theoretical limit as N is of course very large.

Q: Doesn't Maxwell's equation predict radio waves don't penetrate?

A: Maxwell's equations govern electromagnetic phenomena in vacuum only. To model propagation in materials such as the earth a specific model of the electrical properties of the earth has to be created and then coupled to the Maxwell equations. Such models are phenomenological and usually have several parameters that are difficult to measure in-situ.

Q: Can't we just measure the electromagnetic properties of rocks in the lab and then use that in a forward model for subsurface propagation?

A: When material is removed from the ground atmospheric contamination (mainly moisture) changes the electrical properties, so these values are not the in-situ values governing propagation. Apparently Erwin Schrödinger, one of the founders of Quantum Mechanics, measured such changes for his thesis and found the resistivity can change by many orders of magnitude.

Learn more about Adrok's deep penetrating ADR Technology

Download a Glossary of Terms

Term

Definition

ADR

Atomic Dielectric Resonance

Correlation Method

Stacks a large number of traces from a series of stare scans and applies mathematical filtering to give a baseline over which the signal can be described as being of high quality. The signal returns are analyzed to show distinct changes in lithology for the area under investigation

Dielectric Constant (DC)

The index of the rate of transmission of our ADR wave packet through a medium relative to the transmission rate of the beam through vacuum. This is also sometimes called the transmissivity index, or relative permittivity. The vacuum has a dielectric constant of 1. For a medium such as limestone the dielectric constant (er) is typically 9

E-Log (Energy log)

During a stationary scan (“Stare” scan) the ADR transmitter and receiver antennas are positioned at known grid co-ordinates and aimed downward. The energy log (“E-log”) indicator is produced by dividing the Stare scan image data in time windows. Windowing is carried out in equal time intervals or the time axis is migrated to depth after our WARR tracking of dielectric and windowing is performed equal spatial intervals. The data windows are subsequently analyzed and/or enhanced utilizing a suite of signal and image processing techniques such as Fourier analysis, wavelet decomposition, and image enhancement algorithms using RADAMATIC, Adrok’s proprietary data analysis software. Amongst other indicators, this analysis produces the E-Logs which represent estimated energy values as a function of depth and were found to be excellent indicators. In this paper they are plotted on a logarithmic scale

P-Scan

Profile Scan of the subsurface with fixed focus Antenna spacings at ground level. Both Transmitting and Receiving Antennas are moved simultaneously in parallel along the length of the scan line. This produces an image of the subsurface (from ground level) based on the two-way travel time of Adrok ADR Scanner’s beams from Transmitter (Tx) to Receiver (Rx) Antenna. The WARR data converts the P-Scan time-stamps into depths in metres.

Stare

A stationary scan where data collected with both antennae pointing the ground

WARR

“Wide Angle Reflection and Refraction” scan to triangulate subsurface depths from the surface ground level. The transmitting antenna is moved at ground level along the scan line, away from the stationary receiving antenna which is positioned at the start of the scan line. Collected by ADR Scanner at ground level (produces depth calculations)

Weighted Mean Frequency

The frequency and energy values are combined to produce a Weighted Mean Frequency for each measured depth interval. WMF is the energy weighted mean of the frequencies. Therefore, frequency values with a high weight contribute more to the WMF than frequency values with a low weight