Blasting Services system for generating rock face profiles that employs only images taken with a hand-held digital camera is
now in operation.
The BlastMetriX3D system, provided by 3G Software & Measurement
GmbH of Austria, consists of a calibrated camera, two calibrated
lenses, a series of targets and processing software.
Establish Reference Points
Two reference points are established on the
bench top to form a line from which the blast-holes
can be located.
Two targets, known as delimiters, are positioned over the reference
marks. These targets allow the processing software to locate the ends
of the reference line and consist of a single disc on a pole held
vertically over the reference mark.
Position Range Poles The range poles consist of two
targets located on a vertical pole. These targets are normally
positioned close to the toe of the face, or alternatively they can be
located on the bench top.
Take Photographs Two
photographs are required to enable the processing software to produce a
3 dimensional image of the face. The distance between the two
photographs depends on the distance of the viewing point from the face
and should be between 1/8 and 1/5 of the viewing distance.
Download and Process Photographs
The photographs are downloaded into a laptop and processed via the
BlastMetriX3D software. This is a relatively simple process as the
software carries out much of the work in a semi-automatic fashion. The
output of the software is a 3D model of the face with the actual face
image draped over it.
The included software also allows for the locations of the holes to be
entered, relative to the established reference points, along with
inclination and depth. Profiles are then generated showing both the
shape of the face directly in front of the hole and the minimum burden
in any direction. The software generates standard profile drawings and
the burden information can also be displayed as a colour-coding on the
Having determined a suitable drilling plan the holes are drilled and the actual locations, inclinations
and depths measured. The 3D model is then
updated to enable the generation of a final set of profiles so that the explosive loading for each hole
can be determined.
The BlastMetriX3D system provides a simple way of producing a 3D
survey of a face and thereby the profiles suitable for blast design.
A great advantage of the system is that it allows the operator to
combine both survey information and images. This then allows for the
blast-hole explosive loading to take into account both the burden and
geology at the same time.
The system is still under development and does not currently allow for
hole deviations to be entered or for faces with a free-end to be
surveyed. The software developers are currently working on these issues
and Blasting Services looks forward to trialling the final system later