CASE STUDY: Mining Aerial Survey
In April, Scout Aerial Africa conducted a mining survey for Bilboes Holdings at Eastnor, Matabeleland North (Zimbabwe) – one of the largest mining companies in Southern Africa. This survey has been Scout Aerial Africa’s biggest survey project yet which we have successfully completed and delivered within the given timeframe for the project. The success of this project involved both aerial and bathymetric surveys.
CLIENT: Bilboes Holdings
LOCATION: Matabeleland, Zimbabwe
SERVICES: Aerial Survey – Orthomosaics, Digital Surface Models, Topographic Plans, Orthomosaic plan. Bathymetric Survey – Google Overlay, Digital Surface Model, Bathymetric Plan showing pit profile and depth.
The proposed operation sites cover over 7,800 hectares of land spread over 3 major mining sites of the Isabella, McCays and Bubi Mines, located 80 km north of Bulawayo. The area of interest was divided into 3 primary areas.
Due to the scale of this project, a detailed level of planning was required to ensure a smooth transition between each phase of the project from start to finish.
Aerial and bathymetric high-level workflow were designed and introduced to the team. Flight plans were designed based on the operational limit of the aircraft using the latest flight simulation software. Prior to commencing the project, real simulation on a small section of the operational site was conducted to collect a test dataset which was used to process and assess the quality of the data. Proposed ground target positions relative to the operational site were set. To ease the processing phase, the proposed site was sectioned into 12 individual processing blocks which integrated into the full model.
We were also responsible for laying and measuring ground targets to be used to process the imagery collected during the flights. Over 200 ground control points (GCPs) were laid to guarantee enough coverage and accuracy.
After ground targets were laid, our team of RPAS pilots conducted the aerial survey from the designated landing and retrieval (LAR) site to collect aerial imagery. The field support team’s function was to analyse collected datasets. They took the datasets and performed rapid processing onsite to make sure there was enough coverage on the area of interest with high-quality outputs. Datasets were uploaded to the processing team afterwards for full processing.
Collected datasets were organised and processed using advanced photogrammetry software. Deliverables were packaged as per the processing blocks, each with a survey report.
Quality Assurance (QA)
Detailed QA procedures were performed on all the deliverables as per the company’s QA checklist.
We also executed bathymetric surveys on more than 20 pits across the mine complex, using a state-of-the-art remotely piloted bathymetric boat and system equipped with an advanced sonar module designed by our engineering team. Precision GPS stations were also employed, and sonar data captured showed the deepest part of the pit as deep as 10 meters.
Post-Processing Kinematic (PPK)
PPK module, a highly precise GNSS tool, was utilised for the bathymetric survey recording highly accurate geographical positions. These precise coordinates would then be correlated with sonar data. This was done through a smart program, engineered by our software product team, which integrates sonar data and GNSS coordinates to output accurate 3D model of the pits.