Precise Control

One of the most important aspects of land surveying, whatever the task, is the main control. To minimize errors, precise main control is essential. Accurate control is crucial if a project is to be surveyed correctly, or set out correctly.

I have over 33 years experience in providing precise main control.Currently Airedale Surveys Limited uses a Sokkia SET 2120 EDM which has an accuracy of 2mm and 2” of arc, APS 12 precise targets, and a B20 surveyors level. This combination allows any number of main control stations to be precisely surveyed and levelled. Accuracies of plus or minus 3mm are regularly achieved. The reasons for this kind of accuracy being achieved are:

a. Prior to any survey observations I insist that the instrument and targets are field checked to see whether they are in adjustment and

b. Observations are made in a manner that minimizes instrument error.

The projects listed below are projects that demanded the highest degree of accuracy and if this accuracy was not achieved it would have had severe consequences financially and devastating program implications.

Recent Experience / Past Projects.
Sheffield Building Schools for the Future. January 2007 to September 2010.Primary main control observed for 15 of the 17 projects.
Blackburn Retail Centre. October 2008.Precise building and elevation surveys to allow architect to position new shopping centre within existing complex.
Docklands Light Railway Phase 7. October 2007.Precise primary main control for whole project.
South Hook LNG Tanks. August 2006.Establishing primary main control for the whole project.
Hydro Electric Dam Monitoring. Maentwrog Dam, Mid-Wales. Annually 2004 to 2007.Monitoring dam for sub 3mm movement.