RTK in agricultural construction: practical applications on farm sites

Farm construction covers grain warehouses, livestock complexes, silage structures, and production yards. All of these require survey support - from axis stakeout to as-built documentation. RTK has taken over most of that work, cutting field time by a factor of 3 to 5 compared to a total station or optical level.

Foundation leveling

RTK comes into play at two stages here. The first is stakeout: the surveyor loads corner coordinates from the design into the controller and marks points on the ground. A standard rectangular foundation stakeout takes 15-30 minutes. With a total station, two-person crew, and reference benchmarks, the same job runs 2-3 hours.

The second stage is checking the top-of-concrete elevation. Tolerance under standard specifications is 10 mm from the design grade. RTK vertical accuracy is 20-40 mm depending on signal conditions, so it gets combined with an optical level for the final concrete check. For gravel subbase control and rough grading, though, RTK is accurate enough on its own.

Drainage pipe installation

This is one of the most common RTK applications on farm construction sites. A drainage system around a warehouse or farmyard needs a precisely controlled slope. For perforated agricultural drainage pipes with a diameter of 100-160 mm, the standard gradient is 0.003-0.005 m/m (3-5 mm per meter of run). Less than that and the perforated drain silts up.

The operator walks the RTK pole along the trench and reads the actual trench bottom elevation and its deviation from design directly on the controller screen. The crew adjusts excavation depth without stopping work. The as-built drawing with pipe coordinates and manhole elevations is generated automatically from the field log - no second survey pass needed.

Building axis stakeout

On grain storage or equipment yard construction, RTK is used to set out design points directly from coordinates without tying into an existing control network. Open, unobstructed sites - exactly what most farm projects look like - are ideal conditions for this.

Staking out a multi-building complex from scratch takes 1.5-3 hours. The main requirement is a stable RTK fix - either from a local base or a CORS network. On open farmland away from built-up areas, that's rarely a problem.

Site grading and Machine Control

Preparing a building pad - cutting high spots, filling low areas, grading to design elevation - involves a lot of earthwork. RTK-based Machine Control on a bulldozer or motor grader lets the operator grade without a surveyor on hand for every pass. The system continuously compares the blade elevation to the design model and adjusts the hydraulics accordingly.

Machine Control grading accuracy is 3-5 cm. That's fine for subgrade preparation - the final trim pass is always done manually anyway. But unnecessary rework and extra equipment passes drop noticeably: contractors working on larger farm projects report around 20-30% less earthwork time compared to conventional staking.

• Hardstand and yard paving - design cross-fall of 0.5-1% is maintained across the full area by Machine Control
• Grain warehouse floor subgrade - 15-20 mm tolerance, RTK handles it without optical leveling
• Access road embankments - slope control for the carriageway and side batters

Where RTK does not work well

Narrow yards between buildings, areas under metal roofing, and spots close to large steel structures all cause satellite signal multipath and blockage. The fix quality drops, and positional error can quietly reach 5-10 cm with no warning on the display. In those situations a total station tied to known control points is the right tool. RTK is still useful for general open-area checks, just not for close work in confined spaces.