XGRIDS Pro Guide™ / Module 3: Field Technique

Module 3 Quick Field Guide

Speed limits, posture, route structure, transitions, and environment-specific technique — all the numbers and rules you need on site.

Section 1

Speed and Posture Reference

Condition
Speed
Notes
General scanning, feature-rich environments
3 ft/s max
Standard pace. Smooth and continuous.
Corridors, open rooms, low-feature areas
1.5 ft/s
Deliberate, unhurried. SLAM drift accelerates in featureless spaces.
Door and stairwell transitions
1.5 ft/s
Begin slowing 6 to 10 feet before the doorway.
Reflective surfaces, dark areas
1.5 ft/s
Keep moving continuously. Never stop in front of glass.
Data center aisles
1.5 ft/s max
Treat as indoor hallway throughout entire facility.
Equipment and object circles
1.5 ft/s
Circle at 3 to 10 feet distance.
Tunnels and mine shafts
1.5 ft/s or below
Max 1,600 ft per segment. Use Narrow Scene mode in LixelStudio.
Posture Rules
  • Hold the scanner vertically at chest height. Tilt no more than 20 degrees from vertical in any direction.
  • Never scan horizontally (pointed at the ceiling or floor). The LiDAR needs vertical geometry to track correctly.
  • When turning, rotate continuously over 1 to 2 seconds. Do not snap or pivot quickly.
  • Height changes must be gradual over 10 to 15 feet of travel. The viewing angle difference must not exceed 40 degrees at any one moment.
  • Do not stand still to capture detail. Circle the object at 1.5 ft/s instead. Standing still after the first few seconds adds no new data, and rotating in place is not a substitute for circling: SLAM needs trajectory movement through space, not angular rotation from a fixed point.
  • Turn 90 degrees sideways through every doorway for all devices. One side of the scanner faces the room you are leaving, the other faces the room you are entering. This applies to K1, L2 Pro, and PortalCam.
PortalCam-Specific Posture
  • Lighting consistency matters more for PortalCam than for L2 Pro/K1 because PortalCam uses all three sensors (LiDAR, visual, IMU) in its Multi-SLAM system and the visual component is especially sensitive to rapid lighting changes. Avoid sudden changes in light level mid-scan.
  • Do not point directly at light sources, windows, or the sun. Overexposure degrades both visual tracking and colorization quality.
Section 2

Route Structure Checklist

Standard Indoor Route (Backbone-First)
  • Walk all main corridors first before entering any rooms. Establish the spine of the floor plan before branching.
  • Branch into each room from the corridor. Scan the room interior completely, then return through the same doorway you entered. Each room entry and exit is a loop closure.
  • Close loops continuously. Return to previously scanned areas at the end of every major space. For maximum loop closure quality, re-enter the previously scanned area from the same direction and position you originally used. Retracing from the same spot and facing the same direction gives SLAM the highest-confidence match.
  • For corridors over 160 feet (SLAM-only): branch into at least one room and return before reaching the far end. A straight out-and-back walk without branching accumulates uncorrected drift. With RTK Fixed status, corridors up to 500 feet are viable because drift is bounded by the coordinate stream.
  • Return to within 15 to 30 feet of the initialization point at the end of the session from a similar angle to your starting position. This is the final loop closure.

Ending at the starting point is not the same as creating a loop closure. Walking the full perimeter of a floor plan and returning to the start from the opposite direction does not reliably trigger SLAM loop detection. Your return viewing angle must be within 40 degrees of your original viewing angle at that location.

Section 3

Transition Procedures

Interior Door Transitions

Door Entry Sequence
  • Begin slowing 6 to 10 feet before the doorway. Target speed: 1.5 ft/s.
  • Leave the door half open. A fully open door leaves one side of the frame unscanned. A half-open door captures both sides.
  • Turn 90 degrees sideways before stepping through the threshold. One side of the scanner faces back into the room you are leaving, one side faces into the new room.
  • Pause 5 seconds on each side of the doorway threshold. This gives SLAM time to register the geometry of both rooms relative to the doorway.
  • Resume normal speed 6 to 10 feet past the doorway.

Stairwells

Stairwell Procedure
  • Scan the landing at the base fully before beginning the ascent.
  • Walk up one side of the staircase, then return down the other side for bidirectional coverage.
  • Angle the scanner slightly to capture the underside of the flight above you as you ascend. Stay within 30 degrees of vertical.
  • Scan each landing fully on both the ascent and descent.
  • Budget 5 to 10 minutes for a standard three-flight stairwell with proper coverage. Complex stairwells with wide landings or multiple branches may take longer. Do not rush stairwells — they are a high-failure zone and are time-consuming to rescan.
Section 4

Environment-Specific Rules

Tunnels and Long Corridors
  • Maximum 1,600 feet per scan segment. Divide longer runs before starting.
  • Enable Narrow Scene mode in LixelStudio before processing any tunnel or long corridor scan.
  • For multi-segment tunnels, plan a shared overlap point between sessions. When marking the shared point in the second scan, device position must be within 4 inches and 10 degrees of its position in the first scan.
  • Minimum spacing: 15 feet between any two shared points.
  • Slow to 1.5 ft/s or below throughout. In low-light tunnels, slower is better.
  • Place XGRIDS scan targets (the magnetic steel targets included with the K1 and L2 Pro) every 100 to 150 feet in long featureless runs. These are not GCPs and require no surveyed coordinates — they serve as high-contrast SLAM anchors that give the system reliable features to match between passes. If you also need absolute coordinates, supply those targets with surveyed coordinates in LixelStudio during processing, at which point they become GCPs.
Reflective and Glass Surfaces
  • Never stop in front of glass or mirrors. Keep moving at 1.5 ft/s past any reflective surface.
  • Approach glass walls at an angle rather than head-on. An angled approach reduces direct reflection exposure to the LiDAR.
  • For fully-glazed office facades, plan your route to cross glass zones rather than walk parallel to them at close range.
  • PortalCam is more severely affected by reflective surfaces than the L2 Pro or K1 because the visual component of its SLAM system can track reflections as false geometry.
Dark and Low-Light Areas
  • Slow to 1.5 ft/s or below in any dark area.
  • Bring a portable light panel and angle it forward into the area you are walking toward, not downward at the floor at your feet. SLAM is continuously matching new geometry against what it has already seen — the upcoming area needs to be illuminated before you reach it, not after.
  • Camera coloring in dark environments produces poor results. Consider disabling coloring for dark spaces and re-enabling it for lit areas, or plan dark zones as separate no-color sessions.
  • Place XGRIDS scan targets in dark featureless areas before scanning. Even without surveyed coordinates, these targets give SLAM high-contrast features to match against when visual texture is minimal.
Outdoor Environments
  • Outdoor areas require consistent feature density. Do not scan open plazas or parking lots without including surrounding buildings, walls, or fixed structures in the scan path.
  • Do not point cameras at the sun or scan into direct sunlight. Overexposure corrupts camera coloring data.
  • Wind affects PortalCam stability and visual tracking. In windy conditions, walk with the wind rather than against it where possible.
  • L2 Pro 32-300 is required for tall structures and large outdoor sites. The 16-120 and 32-120 models are limited to 400 ft range.
Section 5

Data Centers

Data centers are scanned repeatedly over time for change tracking, equipment audits, and capacity planning. The challenge is repetitive geometry: row after row of identical racks with no distinguishing features. Scan quality and target placement here directly affect how usable rescan comparison is.

Data Center Scanning Rules
  • Speed: 1.5 ft/s maximum in all aisles. The proximity of rack faces on both sides creates a low-feature environment throughout.
  • Walk every aisle. Do not skip cold aisles if hot aisles were already covered. Each aisle provides different rack face geometry.
  • Vary scanner height between aisles where possible. Walk one aisle at chest height and the adjacent aisle at overhead height. Change heights gradually over several feet of travel.
  • Complete loop closures at the end of every row by looping back through the cross-aisle at the far end before starting the next aisle.
XGRIDS Scan Target Placement
  • Space targets every 100 to 165 feet along the scan path, or one per three to five aisles. These are the magnetic steel targets included with the K1 and L2 Pro — not survey GCPs. They serve as high-contrast SLAM anchors in this repetitive-geometry environment.
  • Place each target where the scanner can approach within 3 to 6 feet and circle it during the scan.
  • Keep targets away from hot-aisle vents and active airflow paths. Turbulent air near cooling exhaust can cause vibration. Magnetic attachment directly to a rack panel is preferred.
  • Mark every target in LixelGO during the scan. Unmarked targets are visible in the point cloud but are not used for SLAM correction or georeferencing in processing.
Rescan Alignment
  • Place targets in the same positions as the original scan. For recurring rescans, record target locations permanently with floor coordinates or photos.
  • Plan rescan session boundaries so the new session covers at least 50 feet of geometry that is also present in the session it must merge with.
  • Verify residuals in LixelStudio before leaving the site. A misaligned rescan that is discovered at the office means returning to the facility.
Section 6

Critical Warnings

  • Bad data Moderate excess speed produces no immediate warning in the app. LixelGO does display a "Record Warning Only" alert when SLAM confidence drops severely — which rapid movement can trigger — but normal excess speed degrades data silently. You will not be warned every time you walk too fast. Degraded accuracy is discovered during processing or after delivery. Slow down before the environment forces you to.
  • Bad data Loop closure requires a return viewing angle within 40 degrees of the original. Walking back through a room facing the opposite wall is not a loop closure. SLAM will not detect the overlap and drift continues accumulating. For best results, return to the same position and direction you originally used in that area.
  • Warning Tunnels and long corridors over 1,600 feet must be segmented before scanning. A continuous scan beyond this length is not recoverable in post-processing. Plan segments at 1,600 feet or less.
  • Warning Enable Narrow Scene mode before processing any tunnel or long corridor scan. Processing tunnel data with the default SLAM mode produces significantly degraded results. This setting is in LixelStudio, not in LixelGO.
  • Warning Stairwells take longer than their footprint suggests. A standard three-flight stairwell with correct technique requires 5 to 10 minutes. Complex stairwells with wide landings take longer. Allocate time before arriving on site.
  • Warning Standing still to capture detail adds no data after the first few seconds, and rotating in place does not improve coverage. SLAM requires physical movement through space. Circle the object at 1.5 ft/s instead. For LiDAR-based scanning, rotation from a fixed point adds no new geometry. For LCC Studio (3DGS) processing, the XGRIDS scanning guide states explicitly that standing in the same spot does not improve reconstruction.
  • Warning Do not point cameras at the sun or direct light sources. Overexposure corrupts camera coloring data for the entire scan, not just the overexposed frames. Avoid scanning toward windows in bright sunlight.
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