Photogrammetric Method to Determine Physical Aperture and Roughness of a Rock Fracture
Abstract
:1. Introduction
2. Materials and Methods
2.1. Sample Preparation
2.2. Photography Procedure and Data Acquisition
2.3. Data Processing
2.4. Estimation of Physical Aperture
2.5. Estimation of JRC Values and JRCerror
3. Results and Discussion
3.1. Constructed 3D Models
3.2. Calculated Physical Aperture
3.3. Calculated JRC Values
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
Abbreviations
SfM | Structure from motion | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
JRC | Joint roughness coefficient | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
DoF | Depth of Field | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
DSLR | Canon EOS 5DS R DSLR | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Raspi | Raspberry Pi High-Quality camera | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
GoPro | GoPro Hero 8 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
** using optical profilometry. Water Resour. Res. 2013, 49, 7126–7132. [Google Scholar] [CrossRef]
Figure 1.
Workflow of the photogrammetric method to measure physical aperture: (a) Kuru grey granite sample with a throughgoing rough fracture, (b) top and half parts of the sample are scanned together and separately, (c) cameras used to capture the images of the sample, (d) photogrammetric processing and the calculated camera positions of the whole sample, (e) photogrammetric processing and the calculated camera positions of the two halves, (f) defined distances between markers on the whole sample, (g) defined coordinate system for the whole sample and extracting each marker position in the same coordinate system, (h) 3D point cloud of the sample with top and bottom halves matched in the same coordinate system with applying obtained markers’ positions for each half, (i) physical aperture distribution measured from the digital model, (j) profile extraction, and (k) Joint Roughness Coefficient (JRC) estimation.
Figure 1.
Workflow of the photogrammetric method to measure physical aperture: (a) Kuru grey granite sample with a throughgoing rough fracture, (b) top and half parts of the sample are scanned together and separately, (c) cameras used to capture the images of the sample, (d) photogrammetric processing and the calculated camera positions of the whole sample, (e) photogrammetric processing and the calculated camera positions of the two halves, (f) defined distances between markers on the whole sample, (g) defined coordinate system for the whole sample and extracting each marker position in the same coordinate system, (h) 3D point cloud of the sample with top and bottom halves matched in the same coordinate system with applying obtained markers’ positions for each half, (i) physical aperture distribution measured from the digital model, (j) profile extraction, and (k) Joint Roughness Coefficient (JRC) estimation.
Figure 2.
(a) LED light tripods around the slab and (b) the pattern of measuring the luminous flux on the sample surface as indicated by the numbers.
Figure 2.
(a) LED light tripods around the slab and (b) the pattern of measuring the luminous flux on the sample surface as indicated by the numbers.
Figure 3.
Sketch of the camera position in relation to the photographed sample.
Figure 4.
Visualization of the measurement lines for calculating JRC, B signifies the bottom and T is the top part of the sample.
Figure 4.
Visualization of the measurement lines for calculating JRC, B signifies the bottom and T is the top part of the sample.
Figure 5.
3D point clouds of the sample reconstructed from the images obtained using Canon DSLR camera, (a) the bottom half, (b) the top half, (c) topography of bottom surface (d) topography of top surface, and (e) the whole sample.
Figure 5.
3D point clouds of the sample reconstructed from the images obtained using Canon DSLR camera, (a) the bottom half, (b) the top half, (c) topography of bottom surface (d) topography of top surface, and (e) the whole sample.
Figure 6.
Mean surface point density of the top (a) and bottom (b) half of the sample as a function of camera resolution in megapixels.
Figure 6.
Mean surface point density of the top (a) and bottom (b) half of the sample as a function of camera resolution in megapixels.
Figure 7.
Surface density of the bottom surface in the 3D models.
Figure 8.
The root mean square error (RMSE) of the cloud-to-cloud distance between each low-cost camera model compared to Canon EOS 5DS R DSLR for the top and bottom samples with different rasterization grid interval.
Figure 8.
The root mean square error (RMSE) of the cloud-to-cloud distance between each low-cost camera model compared to Canon EOS 5DS R DSLR for the top and bottom samples with different rasterization grid interval.
Figure 9.
Comparison of cloud-to-cloud distance of low-cost camera point clouds to Canon EOS 5DS R DSLR point clouds of the bottom surfaces. The rasterization grid interval is 0.1 mm.
Figure 9.
Comparison of cloud-to-cloud distance of low-cost camera point clouds to Canon EOS 5DS R DSLR point clouds of the bottom surfaces. The rasterization grid interval is 0.1 mm.
Figure 10.
Comparison of estimated physical apertures obtained by all cameras for different rasterization grid intervals.
Figure 10.
Comparison of estimated physical apertures obtained by all cameras for different rasterization grid intervals.
Figure 11.
Physical apertures determined by cloud-to-cloud distance of bottom and top surfaces of each camera with a rasterization grid interval of 0.5 mm.
Figure 11.
Physical apertures determined by cloud-to-cloud distance of bottom and top surfaces of each camera with a rasterization grid interval of 0.5 mm.
Figure 12.
JRC values with different rasterization grid intervals obtained by different cameras alongside the 2D profiles (L1 to L6).
Figure 12.
JRC values with different rasterization grid intervals obtained by different cameras alongside the 2D profiles (L1 to L6).
Figure 13.
Mean value of the JRCerror extracted from the fracture 3D models rasterized with grid intervals set to 0.25, 0.5, and 1 mm.
Figure 13.
Mean value of the JRCerror extracted from the fracture 3D models rasterized with grid intervals set to 0.25, 0.5, and 1 mm.
Figure 14.
Comparison of the Canon EOS 5DS R DSLR and low-cost camera profiles with 0.25 mm rasterization grid interval. (a) Original profiles of bottom surface, (b) top surface, (c) height differences of bottom profiles, and (d) top profiles.
Figure 14.
Comparison of the Canon EOS 5DS R DSLR and low-cost camera profiles with 0.25 mm rasterization grid interval. (a) Original profiles of bottom surface, (b) top surface, (c) height differences of bottom profiles, and (d) top profiles.
Figure 15.
Comparison of the Canon EOS 5DS R DSLR and cameras profiles with 0.5 mm rasterization grid interval. (a) Original profiles of bottom surface, (b) top surface, (c) height differences of bottom profiles, and (d) top profiles.
Figure 15.
Comparison of the Canon EOS 5DS R DSLR and cameras profiles with 0.5 mm rasterization grid interval. (a) Original profiles of bottom surface, (b) top surface, (c) height differences of bottom profiles, and (d) top profiles.
Figure 16.
Comparison of the Canon EOS 5DS R DSLR and low-cost cameras profiles with 1 mm rasterization grid interval. (a) Original profiles of bottom surface, (b) top surface, (c) height differences of bottom profiles, and (d) top profiles.
Figure 16.
Comparison of the Canon EOS 5DS R DSLR and low-cost cameras profiles with 1 mm rasterization grid interval. (a) Original profiles of bottom surface, (b) top surface, (c) height differences of bottom profiles, and (d) top profiles.
Table 1.
Camera specifications.
Table 2.
Illuminance measurement results on the sample surface. Locations correspond to markings in Figure 2b.
Table 2.
Illuminance measurement results on the sample surface. Locations correspond to markings in Figure 2b.
Table 3.
Shooting distances measured during data capture.
Table 4.
The difference between measured and calculated marker spacing in 3D models produced using each camera.
Table 4.
The difference between measured and calculated marker spacing in 3D models produced using each camera.
Table 5.
Mean surface point density of the 3D point clouds of the fracture surface.
Table 6.
Comparison of cloud-to-cloud distance of low-cost camera point clouds in relation to the Canon EOS 5DS R DSLR point cloud.
Table 6.
Comparison of cloud-to-cloud distance of low-cost camera point clouds in relation to the Canon EOS 5DS R DSLR point cloud.
Table 7.
Measured physical aperture using different grid intervals.
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Share and CiteMDPI and ACS Style
Torkan, M.; Janiszewski, M.; Uotinen, L.; Baghbanan, A.; Rinne, M. Photogrammetric Method to Determine Physical Aperture and Roughness of a Rock Fracture. Sensors 2022, 22, 4165. https://doi.org/10.3390/s22114165
AMA Style
Torkan M, Janiszewski M, Uotinen L, Baghbanan A, Rinne M. Photogrammetric Method to Determine Physical Aperture and Roughness of a Rock Fracture. Sensors. 2022; 22(11):4165. https://doi.org/10.3390/s22114165 Chicago/Turabian StyleTorkan, Masoud, Mateusz Janiszewski, Lauri Uotinen, Alireza Baghbanan, and Mikael Rinne. 2022. "Photogrammetric Method to Determine Physical Aperture and Roughness of a Rock Fracture" Sensors 22, no. 11: 4165. https://doi.org/10.3390/s22114165
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