# To stake out to the tunnel alignment

1. Tap the alignment in the map or select To the alignment in the Method field.
2. If construction offsets are required, enter the required values in the Horizontal offset and/or Vertical offset field. See Tunnel construction offsets.

3. Tap Next.

   On the map, a dashed green line is drawn at a right angle from your current position to the alignment. The elevation of your current position and the design elevation of the computed position are shown.

   The cross section shows your current position and the target, and is orientated in the direction of increasing station. Construction offsets appear as yellow lines. If construction offsets are specified, the smaller single circle indicates the selected position and the double circle indicates the selected position adjusted for the construction offsets.

4. Point the instrument at the position you want to measure. To turn the instrument to the nearest point on the alignment, tap Turn.

   If required, tap Options to stakeout options. See Tunnel survey settings and tolerances.

5. When the point is within tolerance, tap Accept to store the point.

   When using a Trimble SX12 scanning total station in TRK mode with the laser pointer enabled, the Stakeout screen shows the Mark point softkey instead of the Accept softkey. Tap Mark point to put the instrument into STD mode. The laser pointer stops flashing and moves to position itself at the EDM location. When you tap Accept to store the point, the instrument automatically returns to TRK mode and the laser pointer resumes flashing. To remeasure and update the stakeout deltas, tap Measure after you tap Mark point and before you tap Accept. For more information, see Tunnel survey settings and tolerances.

6. Tap Esc to return to the Stake alignment selection screen.