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The FiX1 must be able to see all open sides of a stockpile in order to compute an accurate volume.
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The maximum height to which the stockpile material will be piled and whether the peak may obscure the
view of the FiX1.
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The maximum angle of repose of the material. Steeper sides may be harder for the FiX1 to see, and harder
for the laser to receive returns from.
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The height at which the FiX1 can be mounted. The higher the better for increased coverage.
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The footprint of the area of interest where the stockpiles are located.
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Other parts of the facility superstructure, cranes, scoops and gantries which may obscure the line of sight
of the FiX1, either permanently or temporarily during routine operations on-site.
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Walkways or roads where personnel and vehicles may pass or pause, temporarily obscuring the view of
the FiX1.
5.2.2 Laser range
Under Carlson test conditions, the FiX1 laser ranges up to a limit of 250 m. This range is achievable to 90% reflective
material (e.g. Kodak white card), where the target is larger than the footprint of the laser and where the angle of
incidence is perpendicular to the path of the laser.
However, in real-world situations, the maximum achievable range at any given time or location will depend on a
number of factors. The following conditions will limit the range to an unpredictable degree, produce spurious data,
or, in some circumstances, may prevent any readings from being taken.
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Very dark, unreflective targets absorb the laser pulse and so lead to severely reduced ranges. An example
of this is coal which may give ranges of less than 100 m. Different grades of coal will have different effects.
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An acute angle between the laser and the targeted surface reduces the range as a smaller fraction of the
laser pulse is reflected back to the receiving optics.
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Wet, slick, shiny or very smooth surfaces can reflect the laser pulse away from the receiving optics. This
can result in spurious points beyond the targeted surface, or in holes in the dataset.
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Dusty environments can impede the path of the laser and in some cases may obscure the targeted surface
entirely. This can result in false returns and data appearing in front of the real surface.
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Fog, snow or heavy rain can have the same effect as dust: intercepting or reflecting the laser pulse before
it reaches the targeted surface.
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Direct sunlight can lead to spurious data points between the FiX1 and the sun.
These factors should be accounted for when considering the location of the FiX1.
Note, particularly if the unit is located outside, that some of these factors will change due to the time of day, nearby
on-site activities and weather conditions. Plan for a ‘worse-case’ scenario.
5.2.3 Number of FiX1 units required
For many locations, a single FiX1, suitably positioned, can provide full coverage of the area of interest. However, if
the footprint of the area of interest is beyond the working range of the FiX1 laser, or if the relative height and position
of the FiX1 and the stockpiled material do not allow full line-of-sight coverage of the top surface of the stockpiles,
multiple FiX1 systems may be required. These units form a ‘hub-and-spoke installation.
In case a hub-and-spoke installation is required, multiple mounting locations must be established to ensure the
collected data not only covers the full area, but also that a reasonable overlap is achieved. The considerations listed
in this section should be applied to each mounting location.
