How to Stake Out Points with RTK GNSS: Step-by-Step Guide 2026

In the surveying and construction industries, "stakeout" (frequently referred to as "setting out" in British engineering) is the exact reverse of a topographic survey.

TOPOGRAPHIC SURVEY (DATA CAPTURE):
During a standard topographic survey, you place the GNSS pole on an existing physical feature in the real world (such as a manhole cover or a property peg) and record its coordinate to build a digital map in your CAD software.

STAKEOUT (DATA DEPLOYMENT):
Stakeout works in the opposite direction. You start with a digital coordinate generated by an architect or civil engineer in the office (often provided as a CSV coordinate file or a DXF/DWG CAD drawing). Your goal is to navigate to that exact mathematical coordinate on the physical site and drive a wooden peg, steel pin, or spray paint mark into the ground so construction crews know exactly where to build.

COMMON APPLICATIONS:

• Earthworks & Grading: Staking the extents of a road alignment, including batter boards and slope stakes, to guide heavy machinery.
• Structural Layout: Pinpointing the exact centre of concrete columns, bridge abutments, or steel bolt patterns.
• Utility Trenching: Marking the path for underground sewer, water, and fibre-optic alignments.
• Cadastral Demarcation: Re-establishing lost legal property boundary corners based on historical Tapu or land registry coordinates.

Before you take a single step towards your first target point, you must rigorously verify your equipment setup. Skipping these preparatory checks is the leading cause of massive layout blunders on construction sites.

1. A FIXED RTK SOLUTION:
Stakeout requires absolute precision. Your receiver MUST indicate a "Fixed" RTK solution state on the data collector. This means the receiver has successfully resolved the carrier-phase integer ambiguities and is functioning at maximum accuracy (±8 mm). If your screen shows "Float" or "Single", your position could be off by anywhere from 30 centimetres to several metres. Never attempt to stake a point unless the screen explicitly reads Fixed.

2. HEALTHY DIFFERENTIAL AGE:
Monitor your "Differential Age" (or latency) metric. This represents the time delay between the correction data leaving your CORS network or local base station and arriving at your rover. For precise stakeout, this number must consistently stay below 3 seconds. If it spikes higher, your corrections are stale, and your stakeout accuracy will degrade.

3. EXACT ANTENNA HEIGHT:
GNSS receivers calculate the coordinate at the physical phase centre of the antenna (the top of the pole). To mark the ground accurately, the software must subtract the exact height of the survey pole. If your pole is extended to 2.000 metres, you must ensure 2.000m is entered in ApekSurv. A 10 cm typo here guarantees your cut/fill earthwork elevations will be permanently wrong.

4. KNOWN CONTROL POINT CHECK:
Before staking your first design point, navigate to a known physical control monument on the site. Stake it out. Your rover should report that you are sitting exactly on the point (within your accepted tolerance, typically 10-15 mm). This vital step definitively proves that your coordinate system, geoid model, and CORS datum transformations are all functioning correctly.

The traditional stakeout process was frequently bottlenecked by the surveyor's need to keep the pole perfectly plumb. If the target coordinate landed inside a deep trench, hard against a concrete retaining wall, or underneath the overhang of an excavator, placing a plumb pole over the exact spot was physically impossible.

THE 120° IMU ADVANTAGE:
Modern instruments like the APEKS AP60 Vision, AP40 Laser+, and the compact AP10 have completely eliminated this restriction by integrating a 120-degree calibration-free Inertial Measurement Unit (IMU). When the IMU is active, the receiver continuously measures the exact tilt angle and directional heading of the pole.

HOW IT CHANGES STAKEOUT:
With the IMU engaged, you no longer need to look at the spirit bubble. You can slant the pole up to 60 degrees off-centre (a 120-degree total cone) to easily reach the corner of a building foundation or the invert of a drainage pipe. The receiver mathematically projects the coordinate down the angled pole to calculate the exact position of the tip on the ground. The IMU activates automatically when the receiver achieves a Fixed solution and senses physical movement, making it entirely seamless for the operator.

Chasing a perfect "0.000m" reading on your data collector is a common mistake made by junior surveyors. In reality, GNSS inherently fluctuates by a few millimetres from second to second due to atmospheric noise. Attempting to achieve absolute zero wastes valuable field time. Instead, you must set an appropriate stakeout tolerance based on the specific engineering task.

• Structural Concrete & Steel (10 mm): When staking out foundation lines, anchor bolts, or primary structural gridlines, the tolerance is extremely tight. You should aim to be within 10 mm of the target coordinate.
• Earthworks & Road Subgrade (20–50 mm): When setting slope stakes or guiding bulldozers for bulk earth moving, a tolerance of 20 to 50 mm is standard. The massive scale of the machinery makes tighter tolerances redundant.
• Rural Cadastral Boundaries (30–100 mm): Depending on local jurisdiction rules, marking out expansive agricultural boundaries often permits slightly looser tolerances, provided the point is legally justifiable.

In ApekSurv, you can configure visual and audio tolerance alarms. The software will turn the crosshair green and emit a solid tone only when the pole tip enters your pre-defined acceptable radius, allowing you to work rapidly without constantly reading the fine numbers.