Accuracy assessment of mine walls’ surface models derived from terrestrial laser scanning

Abstract

The monitoring of highwall slopes at open-pit mines is an important task to ensure safe mining. For this reason, several techniques such as total station, radar, terrestrial Light Detection and Ranging (LIDAR) can be employed for surface measurement. The objective of this study is to investigate mesh algorithms, which can be used to interpolate 3D models of pit walls. Experiments were carried out at Coc Sau open-pit mine at Quang Ninh province of Vietnam, and at experimental mine of Akademia Górniczo-Hutnicza University of Science and Technology in Cracow, Poland. First, 3D point cloud data for the study area was acquired by using terrestrial LIDAR, then was used to generate mesh surfaces using three algorithms-Delaunay 2.5D XY Plane, Delaunay 2.5D Best Fitting Plane, and Mesh from Points. After that, the results were rectified and optimized. Subsequently, the optimized meshes were used for generation of non-uniform rational basis spline (NURBS) surfaces. Then, the NURBS surface accuracy was assessed. The results showed that the average distance between surface and point cloud was within range of 5.6-5.8 mm with deviation of 6.2-6.8 mm, depending on the used mesh. Additionally, the quality of surfaces depends on the quality of input data set and the algorithm used to generate mesh network, and the accuracy of computed NURBS surfaces fitting into pointset was 4-5 times lower than that of optimized mesh fitting. However, the accuracy of the final product allows determining displacements on the level of centimeters.

A machine learning approach for the detection of supporting rock bolts from laser scan data in an underground mine

“…The individual scans were registered together to make a unified dataset in the point cloud processing software Leica Cyclone. The hardware used was a Leica C10 laser scanner, as used in other underground studies such as Ganić et al (2011), Chen et al (2018 and Long et al (2018). This instrument has a specified accuracy of ± 6mm per point (Long et al, 2018) and the scan resolution at the chosen setting provides a point spacing of 5mm at 5m from the scanner.…”

“…The hardware used was a Leica C10 laser scanner, as used in other underground studies such as Ganić et al (2011), Chen et al (2018 and Long et al (2018). This instrument has a specified accuracy of ± 6mm per point (Long et al, 2018) and the scan resolution at the chosen setting provides a point spacing of 5mm at 5m from the scanner. The scanner was set to record only laser intensities not optical imagery values.…”

Quality assessment of 3D point cloud of industrial buildings from imagery acquired by oblique and nadir UAV flights

“…There have been many technologies involving 3D mapping ranging from traditional ground surveying such as total station and GNSS to a new generation of remote sensing technologies, including Laser Imaging Detection and Ranging (LIDAR) and UAV [5,6]. While traditional methods can produce a high accuracy but a poor density level of datasets, LIDAR and UAV can offer reasonable/exceptional accuracy and highdensity datasets [7]. In addition, both LIDAR and UAV can create clouds of millions of 3D points with exceptional accuracy at quick times, so they are more effective than the total station and GNSS [7].…”

“…While traditional methods can produce a high accuracy but a poor density level of datasets, LIDAR and UAV can offer reasonable/exceptional accuracy and highdensity datasets [7]. In addition, both LIDAR and UAV can create clouds of millions of 3D points with exceptional accuracy at quick times, so they are more effective than the total station and GNSS [7]. However, while LIDAR technology is still high cost, especially for the highly temporal data collection, the availability of low cost UAV systems allows it to become a common approach to 3D mapping of urban areas.…”

Multitemporal Terrestrial Laser Scanning for Marble Extraction Assessment in an Underground Quarry of the Apuan Alps (Italy)

“…TLS is widely used, among the others, in rock slope studies [1,2,3], river science [4,5,6] and coastal cliff monitoring [7,8]. In recent years, several authors have experimented with the use of TLS both in underground and in open pit quarrying activities [9,10,11,12,13,14]. TLS is based on the acquisition of a high-density point cloud in a very short period of time basically using different techniques: pulse-based (time-of-flight) or phase-based.…”