Find assets in AR

Hold up the camera and see your collected assets as pins where they were surveyed, with an arrow and distance to guide you to one.

On this page

AR shows your assets through the camera, floating where they were surveyed. Instead of reading a bearing and distance, you look around and walk towards the pin. It's for finding things: a buried marker, a valve under leaves, a control point in long grass.

Before you start

  • An iPhone or iPad that supports world-tracking AR. If yours doesn't, the AR buttons don't appear.
  • Camera access for OpenSurvey3D. See Install and permissions.
  • A position fix. A receiver makes the placement much better, but the compass limits it either way (see below).
  • Be outside, near the assets. Only assets within 250 m are shown.

Open AR

There are three ways in:

From Tap Shows
An asset's details Find in AR Every nearby asset, with that one as the target.
Survey → List View items in AR (top of the list) Every nearby asset in the active project.
A project you're browsing without making it active Find these in AR (top of the list), or Find in AR on one of its assets That project's assets.

The last option lets you walk to a marker in someone else's project without switching your active project.

AR opens full screen. The screen stays awake while it's open. Tap ✕ at the top left to close it.

What you see

  • Pins for each asset within 250 m, in the same colours and icons as the map, with the accuracy ring used in 3D. Pins stay the same size on screen however far away they are.
  • A label beside each pin with its name and distance, for example MH-2 · 18.4 m.
  • At the top right, the placement quality, for example ±0.013 m · compass-aligned. This is the accuracy of your current fix. Before a fix arrives it says Locating… or Waiting for a position fix.
  • Below that, how many assets are shown, for example 12 within 250 m.

Lines and areas appear as a single pin rather than a drawn shape.

The target card

When you open AR from one asset with Find in AR, a card at the bottom guides you to it:

  • An arrow pointing towards the asset, relative to where the camera is facing.
  • The asset's name.
  • Walk toward the arrow, or how far above you or below you it is, when that's a metre or more.
  • The horizontal distance to it.

Turn until the arrow points straight up, then walk. The distance counts down as you close in.

Tracking messages

AR needs to see the world to track it. If it's struggling, a message at the bottom tells you:

Message What to do
Move the phone slowly to start tracking Sweep the camera gently over the ground and surroundings.
Slow down — too much motion Move the phone more slowly.
Not enough detail to track here Point at something with texture. Blank walls, water and smooth pavement are hard to track.
Recovering tracking… Hold steady for a moment.
Waiting for the camera… The camera hasn't started. Close AR and open it again.

If camera access is off, AR says so and tells you where to turn it on: Settings › Privacy › Camera.

Re-anchor here

AR places the pins using your position fix at the moment it builds the scene. Tap Re-anchor here at the bottom to rebuild the placement from your current fix.

Re-anchor:

  • After walking a long way, since AR tracking drifts over distance.
  • When your fix has improved, for example after an RTK fix arrives.
  • When the pins look consistently shifted to one side.

How accurate is it?

Diagram: an AR pin is placed from the asset's stored coordinate, your position fix and the phone's compass heading. Only assets within 250 metres are shown, and compass error grows with distance, so AR is for finding and stakeout for setting out.
Where an AR pin comes from, and why it drifts with distance.

AR placement depends on two things: your position fix and the phone's compass.

  • The position is only as good as your fix. With phone GPS alone, pins can be several metres out. With RTK, the fix itself is centimetre-level.
  • The direction comes from the compass, which is typically out by 10–20°, and worse near vehicles, steel, excavators and rebar. A compass error swings every pin around you. The further away an asset is, the further sideways it lands: at 15° out, a pin 50 m away can be about 13 m to one side.

As you close in, the sideways error shrinks with distance. So walk towards the pin, then look for the real thing near where it lands.

Heights are only used when both your fix and the asset have a trustworthy height. Otherwise pins are stood on the ground at about 1.5 m below the phone, rather than inventing a height difference.

Find vs stakeout

Find in AR Stakeout
Good for Spotting where something is from a distance. Getting onto the exact spot.
Direction from The phone's compass. Your GNSS positions.
Accuracy Metres, growing with distance. As good as your fix.
Shows All nearby assets at once. One target, with distances to go.

A good workflow is to walk in with AR until you're close, then switch to stakeout for the last few metres.