The English Heritage Geophysical Survey Database was conceived as an index of all the geophysical surveys of archaeological sites carried out by the Archaeometry Branch of the Ancient Monuments Laboratory. The Branch has a history in archaeological geophysics stretching back to the mid 1960s, and this database is intended to be a first point of reference for those interested to find out what we have done and where. We record details of the geophysical techniques used and, whenever possible, indicate the archaeological monuments or features identified in the area covered by the survey. When applicable we also include reference to any subsequent archaeological investigation at the site that might confirm or refute the interpretation of the geophysical results.
Details of reports on the surveys written for the Ancient Monuments Laboratory report series are also provided along with the report summary for reports in the New Series (post 1985) or a synopsis based on a reading of the report for the Old Series (1985 and before). Additionally for reports written after 1993, it is intended to make a hypertext copy of the report and all its figures available on-line.
We have also expanded the remit of the database to include at least basic details of all surveys of sites in which English Heritage has some involvement. To this end we have made arrangements for a form to be sent out to those receiving permission under section 42 of the Ancient Monuments Act to carry out a geophysical survey over a scheduled ancient monument.
A pilot project to try and record, at least basic details of surveys carried out by colleagues in commercial and academic organisations has added details of over a thousand extra surveys to the database. Unfortunately we are unable to add substantially to this number at present due to a lack of resources.
At present the database contains details of almost all AML geophysical surveys back to 1972, and a further 1500 or so surveys carried out by other contractors either sent to us as part section 42 licence conditions or as a contribution to the database.
Our primary purpose in setting up the database was to provide a unified index of all the geophysical surveys that the Archaeometry Branch has carried out, stretching back over more than 25 years. Hitherto, such records were distributed amongst a number of different record systems both paper and electronic, that have evolved over the years.
As an agency of the UK government we have a duty to make records of our work publically available and, we believe that the provision of free internet access to the database goes a long way to fulfilling that duty.
English Heritage also has a duty to monitor developments in archaeological investigation and to provide advice on the subject to the government. At present it is very difficult to find out whether a particular monument has ever been geophysically surveyed, or even how many geophysical surveys are commissioned each year for archaeological purposes, often all the organisations with an involvement in archaeological geophysics have to be canvassed. Hence our motivation to examine the possibility of recording, at least minimal details of all archaeo-geophysical surveys carried out in England.
We further hope that others will also find the database a valuable first point of enquiry for questions pertaining to archaeological geophysics in this country. Both for research questions (for example: have any geophysical surveys been carried out over grange [a medieval monastic farm] sites?), as well as for evaluation purposes (for example: has any geophysical survey work previously been done over the recently proposed route for a new road?).
We intend to maintain the database in its present form and continue to record details of our own surveys and also all those carried out by other surveyors over scheduled ancient monuments and sites under the guardianship of English Heritage . Where possible we will continue to add details of any surveys submitted to us by colleagues who wish to make such details available to the public. Furthermore we will continue to make hypertext copies of our reports available online through the pages of the Geophysical Survey Database.
In making the database accessible on the Internet we feel that, as a matter of principle, restraint should be minimal. Nevertheless, we are concerned that this should not make sensitive information vulnerable to mis-use (eg by treasure hunters). We are not certain where the optimum balance between accessibility and security lies and would certainly welcome any opinions on the matter.
We have considered a number of options as outlined in this discussion document. In the short term we have decided that we cannot make the national grid references of sites publically available, so that it is not possible to accurately locate them from the database. However, as you will have noticed if you have looked at any of our hypertext reports, it would be difficult to completely disguise the location of a survey whilst still making a useful report available. Hence, we will not publish the hypertext reports of surveys that are considered to be sensitive.
Although it is possible to find the position of a site from the clickable maps, the point you click on is only accurate to the nearest pixel on the image used to display the map. As each pixel represents about a kilometre square this positional information is not that precise.
We hope that, in the not too distant future, we can make a password system available so that archaeological professionals can have access to the restricted information that we have recorded.