Spherical data validation of rock discontinuities orientation from Dronederived 3D Point Clouds
Por:
ManceraAlejandrez, Javier, MaciasMedrano, Sergio, VillarrealRubio, Enrique, SolanoRojas, Dario
Publicada:
1 dic 2021
Categoría:
Geology
Resumen:
This work presents a methodology for the statistical validation of
discontinuity surfaces obtained from point clouds using digital
photogrammetry from drones. Our methodology allows you to review the
quality of the data obtained with photogrammetry and decide whether
these measurements are representative of the discontinuity surfaces that
they analyze. It consists of three steps, the first one being a shape
analysis that allows defining which statistical model should be used:
Fisher for circularly symmetric clusters or Bingham fits better for
axially symmetric clusters. This step also makes the most significant
difference to other works since our methodology starts from the premise
that not all discontinuity surfaces are flat. Therefore, Fisher
parameters do not allow validating data that do not correspond to a
plane.
In the second step of the methodology, we calculate the consistency
parameters that depend on the statistical model defined in step 1. The
parameters are similar for both models; both estimate. which indicates
how much the sample is concentrated around the mean orientation and
validates the existence of this and which is the value of the generating
angle of a cone with a 95 % confidence limit that it contains within
the mean orientation.
Finally, step 3 is used when there are control measurements to compare
the point cloud data and define if both samples characterize the same
discontinuity surface in the rock mass.
The results obtained on a rock outcrop allowed us to observe that the
measurements obtained from the drone faithfully represent the
discontinuity surface analyzed when these were compared with the
measurements made manually with the compass. Furthermore, the dispersion
parameters (kappa and alpha(95)) yielded results that make it possible
to ensure that 1) there is a preferential direction (mean orientation)
and 2) the mean orientation is representative of the entire measured
surface.
Filiaciones:
ManceraAlejandrez, Javier:
Univ Nacl Autonoma Mexico, Fac Ingn, Av Univ 3000,Ciudad Univ, Mexico City 04510, DF, Mexico
MaciasMedrano, Sergio:
Univ Nacl Autonoma Mexico, Fac Ingn, Av Univ 3000,Ciudad Univ, Mexico City 04510, DF, Mexico
VillarrealRubio, Enrique:
Univ Nacl Autonoma Mexico, Fac Ingn, Av Univ 3000,Ciudad Univ, Mexico City 04510, DF, Mexico
SolanoRojas, Dario:
Univ Nacl Autonoma Mexico, Fac Ingn, Av Univ 3000,Ciudad Univ, Mexico City 04510, DF, Mexico
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