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.
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.
Glossary
- 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)