ISO 14001.2004 Environmental Management Accredited
A Registered Organisation with the Institute for Archaeologists (IfA)
Member of The Survey Association (TSA)
Member of the European Ground Probing Radar Association (EuroGPR Assoc)
Achilles UVDB Registration No. 80959
8 members of staff are members of the IfA
How we can help you: With nearly 20 years of experience in carrying out non-intrusive shallow investigations we are happy to offer impartial advice on solutions to a wide range of problems. If we feel we cannot offer a solution ourselves we will always suggest other organisations who may be able to help
This advise would be backed up with:
assessment of the likelihood of success
addressing H&S issues
cost and time scale estimates
The techniques: Techniques typically utilised during shallow geophysical surveys include:
A requirement of planning approval in the UK is that archaeological investigations are carried out in advance of construction works. These will include both buried remains and also above ground structures.
For large sites, perhaps new housing or infrastructure, where there is no known archaeology a general purpose survey is needed. This will often involve an initial reconnaissance survey.
Magnetic Susceptibility A reconnaissance technique which being rapid and cost effective allows large areas to be surveyed in a very short space of time. Areas can then be targeted with more intensive and higher resolution techniques such as gradiometry and earth resistance. Applications (archaeological): for large rural sites to measure the level of past human activity and inform detail survey.
Detailed Magnetic Survey A detailed technique which is still relatively quick and cost effective. The most common technique for locating buried remains in a rural context. Limitations: Strongly affected by magnetic material so can not be used near buildings, fences or in many urban contexts. Applications (archaeological): Locating archaeological features (ditches, pits and other cut features, kilns, hearths etc) on development sites for solar farms, wind farms, housing development etc. Applications (engineering): Locating buried ferrous objects (unexploded ordnance etc).
Earth Resistance A detailed archaeological technique which is ideal for locating buried masonry remains. Not as quick and cost effective as detailed magnetic survey and therefore not as widely used. Limitations: Probes need to be placed into the ground so this technique can not be used over hard surfaces. Applications (archaeological): Locating buried masonry remains (walls, rubble/hardcore, made-ground, roads or trackways) and cut features such as ditches, pits and graves.
Survey to locate the foundations of a section of an old manor that had been demolished due to fire damage. Data collected at 0.5m centres
Ground Probing Radar (GPR) GPR is often the only geophysical technique that can be used in environmental, engineering and archaeological applications on busy urban and industrial sites. It is capable of working through a wide variety of surface materials both inside and outside buildings and structures. Typical locations can range from car parks, highways and waste ground through to factory floors and basements.
This produces a characteristic diffraction in the data.
For small services these diffractions form a hyperbola which allows an average velocity to be determined for the survey.
This velocity is then used to calculate depths for the anomalies observed
Ground Probing Radar (GPR) Different frequency antennas can be used for different applications: High frequency antennae have a high resolution, but shallow depth of penetration, whilst low frequency antennas have a lower resolution but can penetrate to much larger depths. 1500MHz antenna 400MHz antenna 200MHz antenna