GPR and satelite services

What is Terravision Radar Ground Penetration Radar, GPRplus 

Terravision Radar also known as GPRplus is a Ground Penetration Radar (GPR), ground-scanning device, delivering profiles outlining Geological features such as structures, ore bodies, mineralised zones, as well as alluvial horizons and voids.  Data collection is fast – up to 4km of profiles a day and depth of analysis ranges up to 250m below the surface. This will shortly be extended to 500m.

Developed to deploy to Mars to search for water as part of the Russian Space Program, the equipment is perfectly tailored to the exploration environment.  We have a variety of transmitters at high and low frequencies, and different sized antennas to examine target areas of varying depths.

 

Why use us?

Whether you are mining gold, PGMs, kimberlites, copper, iron ore, coal, looking for voids or trying to better understand geological structures, our surveys rapidly accelerate the resource inferred process and drive down drilling costs.  We deliver information and 3-D models, to increase efficiency, such as the location of ore bodies to 250m, voids, fault maps and importantly we show where there are no structures of interest!

Alluvial diamond and gold surveys have been highly effective, reconstructing paleo-channel systems and ascertaining depths of alluvial horizons, and tectonic influences in the bedrock. Void discovery surveys have been carried out with 2x2x2m voids accurately identified down to 35m. This is particularly useful for open pit mine planning, as is water discovery, and fault mapping in open pits. We are also providing “second opinions” for the mining finance / investment community.

 

Benefits of GPRplus include:

  • Real Time Capability.  Immediate processing and analysis allows for on the ground decision making, optimising work programmes, and saving time and money for the client.
  • Lightweight and Rugged – great for operating in remote and rough terrain, able to access areas heavy machinery cannot.  It also only needs a 2-man team to operate.
  • 100,000 times more power.  This allows us to penetrate deeper and through conditions traditionally not suitable to EM systems, such as clay and high salt environments.
  • Water and Ice.  Equipment is deployable on water and ice.
  • Powerful Software Tool.  Allows for fast analysis and reports within 21 days.
  • Minimal Impact.  Non-invasive and with a very localised and light operational footprint, GPRplus has minimal impact on the environment and surrounding ongoing operations.
  • Minimal area preparation.  Quick mapping of target area with minimal preparation of the terrain.
  • Adaptability.  Depending on the geological task, the removable antennas (transmitter antenna and receiver antennas) can quickly be changed, which changes the operating frequency range of the radar.

 

Theory of GPR

Terravision Radar has built on the existing theories of GPR and Electromagnetic (EM) surveying.  GPR is based on ultra-wide band electromagnetic pulse emissions in the subsurface and records their reflections from lithological interfaces and lithological differences, layers or objects.  It is a time-dependent geophysical technique that can provide a 3-D pseudo image of the subsurface, including the fourth dimension of colour, and can also provide accurate depth estimates for many common subsurface objects.  Under favourable conditions, GPR can provide precise information concerning the nature of buried objects

Traditionally GPR uses a transmitter with a power transistor voltage of about 50 V.  (Terravision is able to transmit up to 48MW of power.)  This limited performance to light soils with low signal attenuation (dry sand or frozen soils). Depth of scanning in this case was only in the first few meters, and scanning was not possible at all if the geological section had wet clays or loam. Therefore, instruments of this type were used sparingly, and mostly to solve local tasks in engineering geology and when studying shallow objects.

 

Terravision Radar’s improvements include

  • Pulse transmitter power has been increased by a more than 100, 000 times
  • Stroboscopic transformation replaced to direct detection of signal
  • Terravision uses RC-loaded dipoles to ensure the exclusion of interference in the received signal that suppresses weak signals, whilst also permitting the reception of strong signals
  • The transmitter uses a high-pressure hydrogen discharge, and operates in stand-alone mode without synchronization, thus avoiding the requirement for connecting lines
  • Increasing the sounding depth is possible by reducing the frequency of the signal. Sounding signal damping depends on the frequency as a decrease in the frequency reduces the damping
  • Sounding signal with frequencies of 15-25 MHz and 120 dB potential can provide registration for reflection amplitude from depths of 100-250 m or more (depending on the properties of the section being surveyed)

 

Data Analysis and Radargrams

The geophysical data of the profile is represented as a radargram.  The mono-pulse system waveforms create a cross section radar image of the subsurface.  As each shot is precisely measured this enables the resulting 3D modelling.  The real time display allows us to view the primary form of the data immediately.

The data for processing can be viewed in three typical representations.  Colours are for contrast only to delineate structures and common features.

Waveform Mode

waveform mode

 

Waveform Derivative Mode

Waveform Derivative Mode

 

Binary Mode

binary mode

 


Filtration

The derivative form, through filtering can be used to highlight aspects of the data to best support the survey.  This is illustrated in the single 750m profile that was collected in one pass but through varying the filters is able consider three aspects for the client:

  1. Location of mineralization
  2. Tectonic Structure and
  3. Water.


filtration
For further and more details information on Terravision Radar, please go to www.terravisionradar.com or  contact AFRASIA for more information on GPR.

GPR application images

 
 
 
 
 
 
 
 

Corporate Information

AFRASIA is very dynamic company delivering independent, strategic and qualified professional services and consultancy work for mining companies, engineering firms, financial institutions and investors. Learn More...

Ground penetrating radar (GPRplus)

Ground penetrating radar (commonly called GPR) is a high resolution electromagnetic technique that is designed primarily to investigate the shallow subsurface of the earth, building materials, and  Read more...