Stake out and navigate to a point

The stakeout screen guides you to a point: an arrow, the distance, and how far to go north and east. When you're on it, you can save an as-staked point, a record of where the stake actually went and how far it was from the design.

Before you start

• A project with at least one asset to go to: a design point you imported, a point computed in COGO, or anything you collected.
• A position source. Phone GPS will get you to within a few metres. For setting stakes you need an RTK receiver.

Open stakeout

There are two ways in:

• From Tools: go to Tools → Navigate to asset. In the Navigate to… list, tap the asset.
• From an asset: tap its pin on the map or its row in the list, then tap Stake out / navigate to this asset.
• From a coordinate you type: go to Tools → Stake a typed coordinate. See Stake a typed coordinate.

The Stake out screen opens full screen. Tap Done to leave.

For a line or an area, stakeout goes vertex by vertex. It starts at the vertex nearest you and shows Vertex 2 of 5 (or Corner for an area). Use the arrows either side to move to the previous or next one. To stake a station and offset along a line instead, see Stake to a line.

Reading the screen

With a coordinate system set, ΔN and ΔE are computed on the project grid. Without one, they use a flat local approximation that's fine for walking to a point but less exact over long distances.

The colour tells you how close you are:

• Blue: more than three times the tolerance away.
• Yellow: within three times the tolerance.
• Green: within tolerance. The ring shrinks around a target dot, Within tolerance appears, and the phone gives a success haptic as you cross into it.

Tolerance

The Tolerance control sets when the screen turns green, and it's the pass/fail threshold stored with an as-staked point. Its presets are in the unit that leads your display:

The unit is in the label, for example Tolerance (ftUS). The first time, stakeout picks the tightest preset that's at least twice your current accuracy estimate, or the loosest preset if none is, as on phone GPS. After that it opens on the tolerance you used last. If you switch units, it moves to the nearest preset in the new unit.

Type a tolerance

For a tolerance between the presets, such as 0.03 ft:

1. Tap Type a tolerance under the presets.
2. Enter one number in the unit shown in the title, for example Tolerance (ftUS). A decimal comma works too.
3. Tap Use.

A typed tolerance can be anything from 0.01 to 16.404 ft, or 0.003 to 5 m. Anything outside that range is refused with Not a tolerance and the range. The control then shows Typed: 0.03 ftUS · Change. Tap it to type another, or pick a preset to go back. A typed tolerance is kept exactly as you typed it, and stakeout opens on it next time.

The tolerance is shared by stakeout, Stake to a line and Check a known point.

The haptic fires once as you come within tolerance. It doesn't fire again until you've moved more than a fifth of the tolerance back out, so a rod wobbling on the line doesn't buzz constantly.

Save an as-staked point

1. Set the stake or mark on the target and hold the pole still over it.
2. Tap Save as-staked point. The phone confirms with a haptic.
3. Read the result under the button:
   • Residual 0.034 m, in green if within tolerance or orange if not.
   • ΔN, ΔE and, when heights compare, ΔU. These are measured minus design: a positive ΔN means the stake is north of the design point.
   • A note saying whether it was differenced on the project grid or on a local tangent plane.

The button then reads Stakeout recorded and stays disabled for that vertex, because one stake answers one design point. Move to the next vertex to save another.

Stake a typed coordinate

To stake a northing and easting from a plat or a datasheet without importing a file:

1. Set the project's coordinate system to the plat's zone and unit. Stake a typed coordinate stays greyed out until the project has one.
2. Go to Tools → Stake a typed coordinate. The Stake a coordinate sheet opens.
3. Choose Grid or Ground, to match the coordinates on the plat. See Ground coordinates below.
4. Optionally type a name in Name (optional). Left empty, the point is numbered like an imported one (Design Point 4).
5. Type the Northing and Easting in the zone's unit. The labels show it, for example Northing (ftUS).
6. Optionally type an elevation in Elevation (MSL, …), in your display unit. With one, stakeout shows ΔH as well.
7. Optionally add a note in Note (optional), such as the plat reference.
8. Check Lands at: the latitude and longitude, and From here, how far the point is from you. For a ground entry, it also shows the Grid N and Grid E the point is stored at.
9. Tap Save and stake out. The ordinary Stake out screen opens on the new point.

The app checks the numbers before you can save. A value that isn't a number is refused, and so is a coordinate that lands outside the zone. The message gives the latitude and longitude it would land at, which catches metres typed into a ftUS zone, or values from the neighbouring zone.

The typed point is saved as a Design Point. What you keyed goes in its notes, so the as-staked point has a target to link to, and you can stake or check the same point again later.

Ground coordinates

A plat in ground coordinates has to be scaled back to grid with the same factor and origin the office used to scale it. With Ground chosen, the sheet shows the formula it will use, for example Grid = origin + (ground − origin) × 0.99991234, about grid origin (0, 0).

The factor and origin come from Tools → Ground coordinates…. See Ground coordinates. If nobody has chosen them for this project, a red note says it's using the mean of the project's points about grid (0, 0). Set the plat's factor and origin there first if they're different, or the point lands in the wrong place.

The point is stored on the grid. Its notes say it was keyed as ground, with the values you typed, the factor and the origin, so the conversion can be reversed from the paper.

What the app records

Each as-staked point is stored in two ways:

• A Check Shot asset named Stakeout: <target> (with the vertex number for lines and areas). It carries the full position record, like any collected point, and notes such as Stakeout against STK-701 — 0.034 m at 47° (tolerance 0.030 m).
• A check-shot record linking the measurement to the design point, with ΔN, ΔE, ΔU, the horizontal residual, the tolerance and pass or fail.

These appear in the QA report and in checks.csv in the export bundle, with the kind stakeout. They're never used for site localization, which only uses checks on known control.

Related

• Stake to a line
• Check a known point
• COGO: inverse, traverse and curves
• Import points and routes
• Find assets in AR
• Stakeout basics: cut and fill