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Home 9 Services 9 Planimetric & Vertical Control

Planimetric & Vertical Control

At SurveyWorx, delivering accurate & reliable Geospatial Data is the foundation of what we do.

Site Control Grid

Delivering Trusted Geospatial Data

Comprehensive Control Network Frameworks of permanently fixed Survey Stations established on Site.

At SurveyWorx we deliver Survey Control across both small & large-scale Private Development Schemes, Urban Regeneration Schemes, National Road Projects & major Construction & Engineering Works.

Control Network Frameworks can be related to an Arbitrary/Local Grid or Ordnance Survey National Grid (OSGB36) to Millimetre/Sub-Millimetre accuracies, resulting in high accuracy, quality & repeatability across your Project.

Site Control Grid
Site Control & Setting Out

Planimetric & Vertical Control

Control Network Frameworks

Using a combination of GNSS, Total Station (1”) & Precise Levelling a Control Network of permanently fixed reference points is established on Site. Primary Survey Control is established with PK/Mag Survey Nails & Survey Markers drilled/fixed into hard standing surfaces with Station Description Sheets completed for issue to Client/Final Customer.

PK/Mag Survey Nails & Survey Markers are positioned appropriately to remain stable for a period of approximately 5 years & are designed to withstand damage or destruction over time.

Observations/Reading Procedure

Primary Control Stations are Observed/Occupied (Double Window Averaging) using Leica GNSS Technology, with the resulting data Post-Processed in specialist Survey Software to produce Station Coordinates related to Ordnance Survey National Grid Reference System.

A Closed Loop Traverse is completed using Total Station (1”), 2 Prism Stations mounted on Heavy-Duty Tripods with Forced Centring Technique utilised.

Cross-Bracing Observations/Readings are taken (when/where possible) to ensure adequate Redundancy is present within the Control Network. 3 Rounds of Angles (Face Left & Face Right) Observations/Readings are taken between Primary Control Stations, with Angles & Distances recorded/logged in Field Books to enable additional Verification/Checks.

A double run levelling loop is completed between all Control Stations using a Leica DNA03 & Invar Staff ensuring accurate height information is introduced into the Control Network.

Control Network Post-Processing

Field Observations are Post-Processed through SCC Survey Software to apply a Least Squares Adjustment (& Scale Factor Correction if required). Adjusted Control Network Coordinates are analysed (Residuals, Standard Errors, Error Ellipses) to validate the final Control Network Coordinates.



  • GPS = Global Positioning System.
  • GNSS = Global Navigation Satellite Systems.
  • RTK = Real Time Kinematic.
  • OSGB36 = Ordnance Survey National Grid Reference System.
  • ETRS89 = European Terrestrial Reference System.
  • WGS84 = World Geodetic System (GPS/GNSS)
Get in touch today to discuss your Project & let us deliver an efficient & cost-effective solution to your Planimetric & Vertical Control requirements.

Case Study


Charter Place Square

Engineering Management & Survey

Site Control Grid

Quality Assured & Verified Data

Topographical Land Surveys

Topographical / Land Surveys

Topographical Surveys accurately map & define both natural & man-made features, & determine ground relief across Construction & Development Sites.