General - Faro FOCUS3D X 130 User Manual

scanned environment with additional artificial reference objects, like spheres or
checkerboard paper targets. Spheres and paper targets can be combined within a
scan site. Usually you will achieve more precise registration results when you
have manually placed such targets.
The following tips and hints provide an overview of basic principles which
should be obeyed when working with artificial reference objects like spheres or
paper targets.

General

• Mathematically you need three corresponding references in the two scans
which you like to register to each other. The inclination data captured by the
built-in dual axis compensator may serve well as one reference, such that
only 2 other scanner external references are required. But a higher number of
references per scan may improve the registration results and may make
registration easier and less error prone.
• As artificial targets you should use checkerboard targets or reference
spheres.
• Use targets with a non-reflecting surface.
• Print paper references with laser printers only.
• The references should be easily and clearly visible in the scans.
• Targets should not be positioned symmetrically. They should form a polygon
around the scanner and have varying distances to the scanner. Place them in
the scanning area at varying heights, distances and planes. Avoid placing the
targets in a straight line.
• If the references cannot be placed in an adequate distance to the scanner,
increase the scanning resolution or the size of the targets.
• Do not place targets in close proximity to one another. The distance between
targets should not be smaller than 1m.
• Make sure you see the targets in more than one scan (if you do not have
surveyed coordinates for each targets). A target which is only visible in one
scan is useless for registration.
FARO
Figure 5-29 checkboard and sphere target
53
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Laser Scanner Focus
Chapter 5: Getting Started
3D
X 130 Manual
January 2014