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3D Laser Scanning Terms: A Field-Capture Glossary
This glossary focuses on the vocabulary of reality capture — the terms surveyors, scan technicians, and reviewers use before a single drawing or model is produced. Understanding how a scan is captured, aligned, and quality-checked helps architects, contractors, and owners judge whether the data behind a deliverable is trustworthy. Below are the field-capture concepts we reference most often on Pittsburgh and Western PA projects.
Point Cloud
The primary output of a laser scan: millions to billions of individual measured points, each carrying XYZ coordinates and usually a color or intensity value. The cloud is the raw digital record of a space and the source of truth every downstream CAD drawing or BIM model is traced from.
Registration
The process of stitching multiple scan positions into one coherent coordinate system so overlapping data lines up perfectly. Poor registration introduces ‘ghosting’ or doubled surfaces; tight registration keeps the whole dataset within a few millimeters end to end.
Target-Based vs. Target-Less Registration
Target-based registration uses physical checkerboards or spheres placed in the scene as common reference points, favored where accuracy must be provable. Target-less (cloud-to-cloud) registration aligns overlapping geometry itself, which is faster and less intrusive on occupied sites.
Scan Resolution & Density
How closely spaced the measured points are, usually expressed as point spacing at a set distance (for example, 3 mm at 10 m). Higher density captures fine detail like conduit and moldings but produces larger files and longer processing, so resolution is matched to the deliverable.
Occlusion & Line of Sight
A scanner only records what it can see. Anything hidden behind ductwork, equipment, or furniture becomes an occlusion — a shadow of missing data. Planning enough scan positions to eliminate critical occlusions is the difference between a complete model and one full of guesswork.
Intensity & Noise
Intensity is the strength of the returned laser pulse, which helps distinguish materials and read signage in the cloud. Noise refers to stray or low-confidence points caused by reflective glass, wet surfaces, or moving objects, and is filtered during processing.
Georeferencing & Control
Tying the scan to real-world survey coordinates using a control network or GPS so the dataset aligns with site plans, civil drawings, and adjacent phases. Georeferencing matters most on large sites, additions, and multi-trade coordination.
Deliverable Formats
Registered clouds are exported to formats suited to each tool: E57 and PTS for broad interoperability, RCP/RCS for Autodesk Recap and Revit, and LAS/LAZ for survey and GIS workflows. Choosing the right format up front avoids costly reprocessing.
Coverage & Overlap
The share of a space captured by the scan and the amount of shared data between adjacent positions. Healthy overlap (typically 30–40%) gives registration enough common geometry to lock onto, while thorough coverage ensures no wall, ceiling, or riser is left undocumented.
Why These Terms Matter
When you request a quote or review a scan deliverable, this vocabulary lets you ask sharper questions: How many setups? What point spacing? Target-based or cloud-to-cloud? Is it georeferenced to our site control? The answers determine whether the resulting drawings and models will hold up when trades build against them. If you would like any term explained in the context of your building, our team is glad to walk through it before capture begins.