Every accurate survey, setting out operation and monitoring scheme depends on its control. A survey control network is a framework of permanent 2D or 3D reference points, established to a specified accuracy. All subsequent mapping and construction work is coordinated from it. MatMap designs, establishes and maintains control networks for sites of every size, from a single building plot to linear infrastructure schemes.
Our methods
- GNSS position fixing: static and RTK GNSS observations tied to the OS Net network
- Traversing: high-precision total station traverses for local accuracy and areas with poor satellite coverage
- Precise levelling: digital levelling runs for millimetre-level height control
- Least squares network adjustment: rigorous adjustment with full statistical analysis of the accuracy achieved
Control stations are monumented to suit the site and the project’s life: survey nails, ground markers, concrete pillars or wall-mounted targets. Each is documented with witness diagrams and photographs, so anyone on site can find and use them.
Why good control matters
Poor or inconsistent control is one of the most common causes of errors and disputes in construction. A properly designed network ensures that topographical surveys, setting out, laser scans and monitoring all fit together perfectly. That holds even when different teams carry out the work years apart.
Deliverables
- Control station coordinate and level schedules
- Network adjustment reports with accuracy statistics
- Station description sheets with witness diagrams and photographs
- Transformation parameters between OS grid and local site grids
Who uses our control surveys?
Contractors, engineers and asset owners in construction, infrastructure and defence rely on our control to keep large and long-running projects on grid.