Benchmark Survey & Design is a survey company based in Northern Queensland. They specialise in Topographic Site Surveys, Building and Civil Construction Setting Out, General Drafting, 3D Visualisation, Subdivision and Road Design. Benchmark Survey & Design were tasked by the Porgera Mine Survey Team to map spill grounds in Papua New Guinea. Spatial Technologies were asked to provide a pilot to Benchmark Survey & Design to fly the Aibot X6. Spatial Technologies had 2 years’ experience and flying the X6 and have received advance training from the German manufacturers to do challenging jobs like the PNG mine site.
The Challenge
The biggest challenge was the terrain and access to the site due to extreme slopes and dangerous ground slips and movement. There were locations where you can only access the terrain by a helicopter.
Another effect the high altitude and terrain had was the extreme weather. There would be fog in the mornings and rain in the afternoon leaving us with limited time each day to do the surveys.
The mine had already had someone do this job, but could not deliver the data as specified by the mine site. This was again a case of someone having skills to fly a UAV, but have no knowledge of mapping and processing the data. They also could not carry the more advance sensors like the Aibot X6 can carry.
The data captured will be used to monitor the dump sites of the spill generated by the mine in Porgera. The data will be used to monitor the impact it has on the environment and existing slopes in the valley where the spill is dumped. We had only one week (5days) to complete the job. There were two sites:
- Anjolek – 380 ha
- Anawe – 250 ha
The Solution
Using the Aibot X6 in this project allowed the engineers and environmentalist to see more than just the volumes. Using older data and the point cloud from the model allowed them to look at volume changes. Getting the orthophotos allowed them to see changes in vegetation, and major slope analysis could be done in the affected areas. The UAV captures the data in a much shorter time than what was normally done with a scanner. The Aibot X6 also gets more detail where the scanner could not reach. Safety is a big concern and no surveyor have to endure the rough countryside. This allowed the mine to do the monitoring on a more regular basis and rectify or manage issues sooner rather than later.
The Results
The data produced was better quality than expected by the customer. They only needed sub meter accuracy. By using the best quality sensor and some strategically placed control in conjunction with the RTK on the UAV, we got an accuracy of 10-20cm. This was the optimal combination between flight time, height and ground sampling distance (GSD).
