Two of the Database of British and Irish Hills (DoBIH) editors, John Barnard and Graham Jackson, are founder members of G&J Surveys.  With professional surveying equipment at their disposal they are able to measure heights and drops to 0.1m or better which enables them to resolve most hill-related problems.  They have produced detailed reports of each of their surveys, which you can view by clicking the document links in the Survey report column below.

G&J Surveys have mainly concentrated their efforts on the hills which are borderline for inclusion on the various lists.  Among their notable achievements are the discovery that Mynydd Graig Goch tops 2000ft, that Sgurr nan Ceannaichean is under 3000ft so loses its Munro status, and confirmation that Tryfan is a 3000 footer (3010ft in fact).

For more background information about the G&J Surveys and their methods, see the Database Notes section of the DoBIH website.  If you would like to contribute towards the maintenance of the database, and towards the expense of purchasing and operating the survey equipment, please use the "Donate" button on the DoBIH website.

You may also find John and Graham's article about survey accuracy informative, along with a Performance Evaluation Trimble GeoXH6000 vs Leica Viva GS15.   They have also written an informative article on the use of the Abney Level, a small, light-weight piece of survey equipment you may wish to acquire and carry in your rucksack.