Percise Control & DatumPercise Control & Datum

As Built

At Murphy Surveys, we know the only way to bring a project to conclusion within high tolerance is to establish and maintain a precise control network from the onset and throughout the lifetime of the project.

Several basic steps are required to plan and execute a control survey:

  • Research the existing control in the project area
  • Design a survey to meet the specifications and requirements
  • Determine types of measurements to be captured
  • Determine types of instruments required in order to capture the data
  • Determine the field procedures required
  • Arrange a site reconnaissance and approximate the surveys required
  • Install and traverse station locations
  • Collect data
  • Reduce data according to the requirements
  • Adjust data
  • Prepare the survey report
  • GPS

Murphy Surveys currently have 14 GPS receivers to provide accurate and cost- effective control for your project.

Robotic Accuracy
For high accuracy control, Murphy Surveys employ 1" and 32" Leica Robotic Total Stations with the latest traversing software for excellent results every time. Survey control points would be located with sufficient redundant measurements to enable the detection of measurement errors and ensure consistency which will result in precision estimates correlating with required accuracy.

Precise levelling
Leica DNA 2002 and DNA 10 Digital Levels allow high order levelling datum to be established and proved throughout the site.

Survey Reports
Murphy Surveys supply our clients with control reports detailing levels of accuracy for a product you can trust. When prepared, a survey report would provide a narrative - a detailed description of the project and the procedures, the scope of work performed, a record of information used, in addition to the findings and the basis for the findings. It is absolutely necessary that you have site control that you can trust.  Murphy Surveys have 25 years experience in mapping and land surveying.

Site Control
We are commonly asked to set out a development where there is no site control, or to provide control so that the contractor’s staff can set out on a day-to-day basis. We usually recommend carrying out a boundary survey to establish control in the design grid. If there's a shortage of space for what is on the design drawings (a common occurrence!) it's important to find out before construction starts so that decisions can be taken to rectify the situation.

For projects where it is required to work to Irish Grid or Irish Transverse Mercator map projections, we use GPS receivers to put in the main control stations. Accurate Leica Robotic Total Stations are used then to set out the designed control grid.

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