GPR Survey

Discover the Depths with Twenty20 Surveys: Leading Subsurface Insights

Bringing Clarity to the Depths Below

We Operate in These Areas

Wiltshire: Swindon, Salisbury, Chippenham, Trowbridge, Melksham, Devizes, Warminster, Amesbury, Marlborough, Bradford-on-Avon.

Hampshire: Southampton, Portsmouth, Basingstoke, Gosport, Waterlooville, Winchester, Andover, Farnborough, Aldershot and Fareham.

Dorset: Bournemouth, Poole, Weymouth, Christchurch, Ferndown, Dorchester, Bridport, Shaftesbury, Lyme Regis and Swanage.

Somerset: Taunton, Yeovil, Bridgewater, Frome, Minehead, Weston-super-Mare, Wells, Glastonbury and Cheddar.

Berkshire: Reading, Slough, Bracknell, Maidenhead, Wokingham, Windsor, Newbury, Thatcham, Sandhurst and Ascot.

Oxfordshire: Oxford, Banbury, Abingdon, Bicester, Witney, Henley-onThames, Wallingford, Chipping Norton and Thame.

Surrey: Guildford, Woking, Epsom, Esher, Camberley, Godalming, Reigate, Leatherhead, Farnham and Horley.

West Sussex: Crawley, Worthing, Bognor Regis, Littlehampton, Chichester, Arundel, East Grinstead, Haywards Heath, Burgess Hill, Horsham, Midhurst and Haslemere. 

Gloucestershire: Gloucester, Cheltenham, Kingswood, Filton, Stroud, Cirencester, Tewkesbury, Dursley, Lydney and Nailsworth.

Bringing Clarity to the Depths Below

Step into the future of subsurface exploration with Twenty20 Surveys. Our pioneering Ground Penetrating Radar (GPR) surveying services redefine how you navigate buried utilities and unveil hidden subsurface anomalies. With precision as our guiding principle, we empower your projects with insights that enhance safety, efficiency, and accuracy.

GPR Data post processing for buried utilities and anomalies
GPR Survey Data Collection

Our Expertise

Why Choose Twenty20 Surveys?

GPR Survey Data Collection With IDS Opera Duo
GPR data post processing for buried utilities and features

Industries We Empower

Embark on Discovery

Whether you're venturing into construction, utility upgrades, or environmental assessments, Twenty20 Surveys is your trusted partner in navigating the subterranean landscape. Contact us today to unveil the hidden dimensions of your project. Let's shape the future together.

Contact Us - E:info@gpr-survey.co.uk  T:01722 500695 M:07875176232

Twenty20 Surveys: Illuminating the Subsurface. Your Premier Subsurface Visionaries.

GPR Survey for Highways Improvements Scheme
GPR Survey at Portland Port Cement expansion project

How does GPR work?

GPR works by sending an electromagnetic pulse into the earth. This pulse travels through different materials at varying speeds, and some of the energy is reflected back to the surface when it encounters a material with differing physical qualities. As long as you know how long it takes the pulse to travel to the target and back, and you know what material the pulse travels through, you can estimate the target's depth. 

How deep a GPR system can ‘see’ is dependant upon the frequency of the antenna employed, as does the size of the object that can be discovered. High frequency antennas can detect minuscule features as small as a few centimetres across, but they can only penetrate a few metres at best. Lower frequency antennas are capable of penetrating deeper but can only resolve bigger objects.

The amount of energy reflected is determined by the difference in material characteristics. Because the contrasts between materials, such as air and water or soil and metal, are great, larger reflections result, and features such as huge voids or buried metallic items make ideal targets.

What is GPR?

Ground Penetrating Radar (also known as Ground Radar, GPR, Impulse Radar Ground Probing Radar, Sub-surface Radar and Surface Penetrating Radar) was originally developed for mapping geological features. It is now increasingly used as an NDT survey technique in Civil Engineering and offers a unique non-invasive and non-destructive means for the characterisation of the subsurface and subsurface features.

Ground Penetrating Radar surveys can be used on a wide variety of materials, most commonly soil, concrete, masonry and asphalt.

GPR Survey on-site markout
GPR Survey Fuel Tank Detection

How are GPR Surveys Undertaken?

GPR surveys are typically conducted by moving the device along a straight line and collecting the data. This results in a profile that is a vertical slice into the earth. Data processing and interpretation software can be used to process the data and interpret the findings. A three-dimensional representation of the subsurface can be created by surveying numerous similar profiles tightly spaced together and typically in two directions. Timeslice pictures of an area in plan at a given depth below the earth may then be produced.

A GPR survey can also be performed in scanning mode, in which no data is saved and features are marked up on the ground as they are discovered in real time. Although these sorts of surveys are typically less expensive owing to the reduced time spent in the office, they must be approached with caution because they are largely dependent on the operator's competence and experience. Even in the hands of an expert geophysicist, feature identification rates in a scanning survey are often lower than in a thorough postprocessed survey.

Why are GPR surveys conducted?

Because of its ability to identify plastic pipes, GPR is extensively employed in utility mapping, but it also has a variety of other uses. It is beneficial since the same data may be analysed for a variety of reasons. A comprehensive survey, for example, can be conducted to detect utility services and any other below-ground dangers, such as voiding, underground fuel tanks/drums, or in-situ foundations. It may also be used to integrate a utility survey with an archaeological survey or something similar. This may need the use of several antennas to offer varying levels of deep penetration, although doing the surveys concurrently typically results in cost savings.

GPR surveys are helpful as a supplement to a magnetic or conductivity survey for buried features since they offer more specific information on the depth of anomalies. For brownfield reconnaissance or to characterise an unknown region prior to invasive site studies, a combination of electromagnetic methods and GPR is frequently utilised. They can also be useful for detecting mine shafts and the remnants of mine workings.

High frequency GPR scans are used to study pavement and road construction, discover structural problems, and perform concrete assessments such as calculating ground slab thickness or mapping out rebar within the slab. Road surveying may be done with vehicle-mounted specialised antennas, allowing data to be taken at traffic speeds and eliminating the need for traffic management measures, road closures, and inconvenience to the general public.

Bedrock profiling, mapping quaternary sediments, locating landfill dumps, and monitoring changes through time are examples of geological and environmental uses. GPR may be used to map out features like badger setts, rabbit warrens, and tree root networks, offering a non-intrusive approach with little disruption.

GPR Data Processing

How can we help?

Twenty20 Surveys uses trained geophysicists to define and carry out all GPR surveys, so you can be certain that survey execution, data processing, and interpretation are handled by professionals. Contact us to discuss any project or application, and we will be able to advise on the optimal survey technique, as well as if GPR is the best to use.