Comparative Analysis of Stockpile Volume Estimation using UAV and GPS Techniques

Mining operations involve the extraction of minerals of economic value from the earth. In surface mining operations, overburdens need to be stripped in other to reach the ore. Large volumes of waste as well as ore is stripped in the process. Various technologies have been used to aid in stockpile volume estimation. Notable among them are the Total Stations and Global Positioning Systems (GPS). However, labour, safety and time has challenged the use of these technologies. Unmanned Aerial Vehicle (UAV), commonly known as drone is an emerging technology for stockpile volume computations in the Mine. UAV technology for data collection is less labour intensive, safer and faster. Therefore, this study applied the UAV technology in an open pit to estimate stockpile volumes from a Mine. For the purpose of this study, GPS and UAV data were collected for measuring stockpile volumes of materials mined. The actual volumes of stockpiles A, B, C, D (Case 2), produced differences of 0.05% for A, 0.05% for B, 0.08% for C, 0.07% for D and 0.03% for A, -0.03% for B, 0.03% for C and 0.04% for D, for the GPS-based and the UAV-based techniques, respectively. The GPS-based technique generated moderate accuracies for volume estimation, but was time consuming and labour intensive, compared to the UAV-based technique; which was faster and less labour intensive. The UAV-based technique was the most accurate, safest and is capable of mapping large areas rapidly. It is therefore recommended that UAV survey be incorporated in stockpile volume estimation. Keywords: UAV, GPS, Stockpile, Mine, Total Station

Accuracy of waste stockpile volume calculations based on UAV Photogrammetry

Received: February 1st, 2023 ; Accepted: June 3rd, 2023 ; Published: July 6th, 2023 ; Correspondence: [email protected] environmental supervision, it is necessary to measure waste piles volume to determine whether the activities of the waste manager comply with the established requirements. The aim of this research is to determine whether the model, formed from images collected with low-priced unmanned aerial vehicle (UAV) - not with Real Time Kinematic Global Navigation Satellite System (RTK GNSS) capability - is sufficiently accurate to carry out waste-related surveying. Data collection took place in spring 2021 at the Aardlapalu transhipment station in Tartu County. The objects of the research were an unscreened composting pile and a covered composting pile. In the fieldwork, terrestrial laser scanning and photogrammetric flight were carried out. The reference value was the volume of the model formed from the data of laser scan. The volumes of all models formed by the photogrammetric method were within the permissible difference of 10% provided by law. The most accurate results were obtained from the covered composting pile with an overlap of 70% × 70% and 21 ground control points (GCPs). Using these parameters, the absolute error of the model was 1.48 m³ and the relative error was 0.65%. The most inaccurate results were obtained from the unscreened composting pile with an overlap of 80% × 80% and 21 GCP-s. The research confirmed the hypothesis that sufficient accuracy to calculate waste piles volumes can also be achieved by using a cheaper UAV and camera and with software not specially designed for photogrammetry, design, and drawing

ASSESSING THE APPLICATION OF THE UNMANNED AERIAL SYSTEMS (UAS) IN EARTHWORK VOLUME MEASUREMENT

Earthwork operations are often one of the major cost items on infrastructure construction projects. Because earthwork is largely influenced by unstable construction conditions and organization plans, it becomes the emphasis and difficulties of the cost control in the construction process. Therefore, precise estimates of actual earthwork volumes are important for both owners and contractors alike to ensure appropriate payments are made. However, measuring work on site requires lots of time and labors because of various and irregular site conditions. Conventional measurement methods, such as planned quantities from the drawings or estimates from equipment activity, are rough estimates with significant opportunities for errors and safety concerns. Recently, unmanned aerial systems (UAS) have become popular for numerous surveying applications in civil engineering. They require less cost and time consumptions compared with traditionally manual methods. Also, they are able to perform photogrammetric data acquisition with equipped digital cameras in hazardous, complex or other conditions that may present high safety risks. However, UAS photogrammetry for research applications is still in its infancy, especially in construction management, and research conducted on UAS photogrammetry for earthwork volume estimation are very limited. Therefore, this research intends to investigate and validate the feasibility and efficiency of utilizing the UAS photogrammetry surveying technique to estimate earthwork volume. The research is conducted into three steps based on distinct case studies: firstly, adapting a basic analysis through a case study to preliminarily prove the effectiveness of the UAS photogrammetry method in earthwork volume measurement; also providing an analytical foundation for further utilizations; secondly, Quantitatively assessing the impact of flight parameters and environmental factors on the accuracy of UAS photogrammetry in earthwork volume measurement and identifying the most influential individual or combinations through observations and a statistical multiple regression analysis; at last, comparing volumes calculated by using the UAS platform and other two conventional methods which are Average-End-Area method and grid method in AutoCAD to further validate the feasibility of using the UAS technology in the process of earthwork volumes estimation. The results indicate that the UAS is an effective method for earthwork volume measurement. According to published standards, practice experience, and literature, the measurement errors are in an acceptable range when parameters are under control. In addition, the UAS demonstrates its advantages in balancing between the accuracy and efficiency compared with conventional earthwork volume measurement methods

UAS as an Inventory Tool: A Photogrammetric Approach to Volume Estimation

Unmanned aircraft systems (UAS), also referred to as unmanned aerial vehicles (UAV) or remotely piloted vehicles (RPV), are associated with unmanned aircraft either controlled by a pilot on the ground or pre-programmed with specific flight paths. Small UASs have seen a massive increase in public interest in recent years as hobbyist platforms; they are, however, a potentially powerful tool in remote sensing and geospatial applications. Due to the increased availability of low-cost UAS, this technology could soon revolutionize many industries, including those that require volumetric estimation. Traditionally volumetric inventories have been performed with tape measurements, and in some instances where accuracy is of utmost importance, survey grade GPS and/or terrestrial light detection and ranging (LiDAR) equipment. UAS platforms can bridge a gap between traditional methods by providing accurate volume estimates quickly and efficiently along with valuable 3D digital data for a historical record. This project addressed this problem using photogrammetric techniques with an inexpensive UAS. Methods of data capture and post processing techniques were explored. Volumetric accuracies were assessed by comparing collected data against in situ reference measurements and engineering diagrams. The results show a promising future for UAS and photogrammetric volume estimation that is both cost and time efficient. Out of thirteen objects surveyed six had a relative error less than 5% and exhibited good quality 3D reconstruction. Of the remaining seven objects, four had a relative error greater than 15% and exhibited a very poor 3D reconstruction. The ability to accurately estimate volume is directly proportional to the quality of the 3D model with the highest quality scenes exhibiting the highest accuracy volume estimates. This project has demonstrated that when suitable circumstances are presented and 3D reconstruction is met with a high level of success, inexpensive UAS and photogrammetry present a powerful tool for performing volume estimation of many objects. Future efforts should include research into the optimization of equipment parameters as well as the effects and limitations of site conditions in order to improve 3D modeling and thus volume estimation

Volumetric Change Calculation for a Landfill Stockpile Using UAV Photogrammetry

A growth in population and urbanization is the major factor of accretion in municipal solid waste (MSW) generation in Malaysia. The higher percentage of MSW particularly in Peninsular Malaysia, a quantity of 16,200 tons per day in 2001 increase to 19,100 tons per day in 2005 which make an average of 0.8 kg/capita/day. The amount continues expanding yearly and approximately 8 million tons per day especially in urban areas. Hence, the landfill management has to design a landfill using basic design parameters method which use past record to complement with the correlation factor during the situation. However, this method will exert more time before producing the result. This research aims to consider the calculation of volumetric change calculation for a landfill stockpile using Unmanned Aerial Vehicle (UAV) photogrammetry and predict the targeted life span as an alternative method. The case study is located at Rimba Mas, Mukim Titi Tinggi, Perlis. The process involved throughout this study are planning and preparation before the flight, data collection using UAV, image processing and analyzing data from the image. This study focusses more on the method to calculate the volume using UAV photogrammetry and generate the data into Pix4dmapper. This observation took 2 months periodically to oversee the changes in volume at the landfill site. The result of analysis showed that, there were differences and increasing in the volume of waste for each months. The volume information obtained from UAV photogrammetry and the Pix4dmapper software can help in future for better plan in managing the landfill and MSW

Garud Survey: A Case of Improving Safety and Transparency in Mining Operations Using Drone Technology

SAI Minerals Pvt. Limited (SAI Minerals), a renowned company engaged in mining cement-grade limestone and manufacturing cement in Rajasthan, India, has been grappling with recurring survey reconciliation and safety issues across its mining operations. Additionally, in compliance with new government regulations, they are now required to conduct aerial surveys and submit digital images and survey reports to the Indian Bureau of Mines (IBM). SAI Minerals sought a permanent solution to these challenges and approached Garud Survey Private Limited (Garud Survey), a technology-driven surveying agency. SAI Minerals recognized that these issues not only impacted their production but also tarnished the company\u27s reputation in the mining industry due to frequent accidents. Garud Survey recommended that the best approach to address the problem was to make the survey process faster and more accurate, enabling all stakeholders to have a clear and up-to-date view of the operational status. Garud Survey proposed the implementation of cutting-edge technology to identify and address the root cause of the problem. This case further explores the application of system analysis and design to the adoption and implementation of the latest technology in a real-world use case, as well as the challenges associated with managing change

Investigation of Strategic Deployment Opportunities for Unmanned Aerial Systems (UAS) at INDOT

Unmanned aerial systems (UAS) are increasingly used for a variety of applications related to INDOT’s mission including bridge inspection, traffic management, incident response, construction and roadway mapping. UAS have the potential to reduce costs and increase capabilities. Other state DOTs and transportation agencies have deployed UAS for an increasing number of applications due to technology advances that provide increased capabilities and lower costs, resulting from regulatory changes that simplified operations for small UAS under 55 pounds (aka, sUAS). This document provides an overview of UAS applications that may be appropriate for INDOT, as well as a description of the regulations that affect UAS operation as described in 14 CFR Part 107. The potential applications were prioritized using Quality Function Deployment (QFD), a methodology used in the aerospace industry that clearly communicates qualitative and ambiguous information with a transparent framework for decision making. The factors considered included technical feasibility, ease of adoption and stakeholder acceptance, activities underway at INDOT, and contribution to INDOT mission and goals. Dozens of interviews with INDOT personnel and stakeholders were held to get an accurate and varied perspective of potential for UAVs at INDOT. The initial prioritization was completed in early 2019 and identified three key areas: UAS for bridge inspection safety as a part of regular operations, UAS for construction with deliverables provided via construction contracts, and UAS for emergency management. Descriptions of current practices and opportunities for INDOT are provided for each of these applications. An estimate of the benefits and costs is identified, based on findings from other agencies as well as projections for INDOT. A benefit cost analysis for the application of UAS for bridge inspection safety suggests a benefit cost over one for the analysis period

Monitoring and Computation of the Volumes of Stockpiles of Bulk Material by Means of UAV Photogrammetric Surveying

The monitoring and metric assessment of piles of natural or man-made materials plays a fundamental role in the production and management processes of multiple activities. Over time, the monitoring techniques have undergone an evolution linked to the progress of measure and data processing techniques; starting from classic topography to global navigation satellite system (GNSS) technologies up to the current survey systems like laser scanner and close-range photogrammetry. Last-generation 3D data management software allow for the processing of increasingly truer high-resolution 3D models. This study shows the results of a test for the monitoring and computing of stockpile volumes of material coming from the differentiated waste collection inserted in the recycling chain, performed by means of an unmanned aerial vehicle (UAV) photogrammetric survey and the generation of 3D models starting from point clouds. The test was carried out with two UAV flight sessions, with vertical and oblique camera configurations, and using a terrestrial laser scanner for measuring the ground control points and as ground truth for testing the two survey configurations. The computations of the volumes were carried out using two software and comparisons were made both with reference to the different survey configurations and to the computation software