Home » News » Drones for Accurate Topography Mapping

Drones for Accurate Topography Mapping

12 February 2017

United States Agency for International Development (USAID) Indonesia through USAID Indonesia Clean Energy Development (ICED) II piloted the use of unmanned aerial vehicles (UAV), also known as drones, for topography mapping. This initiative is part of an effort to ensure sound renewable energy project development, especially in obtaining accurate data for renewable energy projects. Technically, the drones will provide more precise digital elevation models and three dimensional representation of terrain surface of renewable energy project sites.

On January 17-19, 2017, through a subcontractor that has won a competitive bidding process, the project conducted a trial flight for the drone at Sapaya Mini Hydro Project (MHP). The subcontractor demonstrated the use of copter drone to collect data for topography mappting. This type of drone takes off and lands vertically with limited traveling time of 15-45 minutes and exploration area of 10-30 kilometers (about 100-500 hectares). Another type of drone that was put on a trial flight was fixed wing drone. This type is able to cover 70-100 kilometers long or 900-1,500 hectares area with 50-90 minutes of flight duration. There was also a drone with light detection and ranging (LIDAR) equipment that used pulsed laser to measure ranges of variable distances to the ground. This particular equipment is able to detect land surface topography in densed vegetation area, while regular camera mounted on drone only can only capture trees’ canopy. The subcontractor also presented preliminary results from collected data and documentation process from previous drone flight tests.

The subcontractor will compare topography mapping methods using drones with LIDAR and camera equipment against conventional surveying instruments such as total station. They will also assess which types of drone such as copter and fixed wing or vertical take off-landing fixed wing are the most suitable for mini hydro power topography mapping.

By using drone as a tool, topography mapping activity is expected to be far more accurate, less time consuming, and more efficient. Topography mapping will be useful for detailed engineering design (DED) development, following a finalized sound feasibility study.

Sapaya MHP is reachable through curvy mountain road from that stretches for 60 kilometers (37 miles) away from the low-land Makassar, the capital of South Sulawesi Province to the hills of Gowa District. The 85 square kilometers (21,000 acres) catchment area, where the 5 Megawatt (MW) mini hydro project sits, is verdant forest bordering with a protected forest area. Sapaya MHP expects to obtain its power purchase agreement (PPA) by the end of 2017. It will move forward to financial close, detailed engineering design (DED), construction phase, and eventually commercial operations date. Should all go well, Sapaya MHP would be in operations in two years from 2019. The mini hydro project will provide 28 Megawatt hour (MWh) of annual energy, where the community of Bungaya subdistrict will benefit from the electricity supply.

USAID ICED II plans to disseminate the final report that compares two different topography mapping methods to project developers that have been receiving USAID ICED II technical assistance.