Utility of Large Scale Photogrammetric Techniques for 3-D Mapping and Precision Iron Ore Mining in Open Pit Areas

Abstract

Precision mining and optimization of ore mining practise are gaining more importance as the global demand and competition for exploring the raw mineral material has grown manifold with increased industrialization world-wide. The overall process of mining activity involves ore identification, estimation, planning, excavation, transportation etc. The activity requires accurate mapping, monitoring and proper management of information pertaining to ore stockpile, mining pits and infrastructure of the areas on a regular basis. Of late, advancements in remote sensing techniques have paved a way for digital management of the mining activity. Especially, use of photogrammetric techniques for open pit mining are found to be highly accurate and effective in capturing, monitoring, mapping, managing the information pertaining to mining in a three dimensional (3D) space. Capturing of information pertaining to mines in 3-D perspective with respect to a specific location on the terrain is highly effective in accurate estimation of ore reserves, exploration and reclamation planning, ore continuity mapping and decision making. However, precision mining requires the use of large scale photogrammetric techniques with high resolution imagery of gigabytes size at mapping scales range from 1: 1000 to 1: 5000. In addition to that, the entire procedure involves the use of state-of-the- art software and hardware for fast processing of data and subsequent digital output generation. Above all, involvement of skilled photogrammetric experts with specialised knowledge on open pit mining is very much essential for accurate interpretation and delineation of the resources. A project was carried out for the 3D mapping of iron ore stockpiles, pits and infrastructure areas at various sites. The stockpile and pit mapping is used for very precise volume measurements and the infrastructure mapping is used for general mine planning activities. High accuracy is critical, as the data and volume reports are used to calculate the value of the ore being extracted, and any errors in the mapping data can result in incorrect payments of large amounts of money. Since, the timeline specified to complete the task is very short, it is crucial that the staff doing the final volume computations and downstream processing should receive the accurate data, correctly coded and mapped according to the standards outlined. The study has demonstrated a typical workflow for the effective use of close range photogrammetric techniques for 3D mapping and iron ore mining in open pit areas. The study also sees a brighter outlook and challenges of upcoming aerial and terrestrial photogrammetric technology for precision mining.