4.5 Control Point Marking During Scanning

Naming Convention

Point names are case-sensitive. The name you type in LixelGO at the marker must match the name in your coordinate file exactly, character by character, including capitalization. There is no fuzzy matching and no warning at processing time. If the names differ, the point is ignored.

Naming Rules

• Use short, distinctive names you can type without error in the field
• Use only ASCII letters and digits. Avoid spaces, punctuation, accented characters, and symbols
• Set a convention before site (project code plus sequence number is reliable)
• Use the exact same name across every scan that shares the same physical point for Map Fusion

L2 Pro and K2 Workflow

Marking a control point means seating the scanner on the exact surveyed point. The procedure is the same for both devices.

1. Confirm the Target Is on the FloorThe marker can be an XGRIDS reflective sticker, a checkerboard target, or any clear, stable floor marker. It must sit on a flat, floor-level surface where the scanner can rest on top of it and stay vertical. Never mark a control point on a wall.
2. Seat the Scanner on the Exact PointPlace the scanner on the control point so it sits vertical, using the control point base to seat it on the exact spot. Set it down gently. Jarring the device at placement adds positional error at that point that cannot be corrected later.
3. Add the Control Point in LixelGOWhile the device is stationary, open the control point interface and type the point name exactly as it appears in your coordinate file, including case. Confirm and wait for the success message before moving.
4. Lift Slowly and ContinuePick the scanner up slowly. Sudden movement immediately after marking degrades that point. Remain near the marker for a few seconds before moving on.

PortalCam Workflow

The PortalCam procedure differs because the device sits on a tripod rather than resting on the ground. Control point support requires recent LCC Scan and PortalCam firmware; confirm both are up to date before relying on it.

1. Deploy the PortalCam on Its Tripod at the PointSet up stably at the control point. Choose good lighting, clear texture nearby, and open space. Avoid corners, dark alcoves, and areas next to mirrors or glass.
2. Add the Control Point in LCC ScanOpen the control point interface and type the name. Hold the device stationary for at least 5 seconds after submitting. The extended hold ensures enough scan data is collected at the stationary position.
3. Circle the Point After MarkingWalk the PortalCam in a circle around the point to capture surrounding geometry from multiple angles. This improves target detection in LCC Studio.

Marking for RTK Accuracy Verification

When verifying RTK accuracy against target stickers, the procedure differs from GCP marking. You do not seat the device on the target. Walking around the sticker while scanning is enough to capture it for verification, and the device does not need to be stationary.

The sticker still needs to be scanned well for automatic target detection. Walk around it at close range, within 0.5 m (1.6 ft), and make sure it is clearly visible in the scan path before moving on.

Ending a Session After the Last Control Point

If the last action before ending the scan is marking a control point, do not stop immediately. Wait at least 15 seconds after the confirmation before ending. Stopping too soon means the point carries insufficient scan data around it, and LixelStudio may not recognize it.

The 15-second rule is a minimum. If the project permits, continue scanning for 20 to 30 seconds and walk a small loop before ending, to give the last point full coverage in the dataset.