Earth-Volume measurement of small area using low-cost uav

In the civil works, the measurement of earth-volume is one of the important elements in the estimation of the reasonable construction cost. Related studies mainly used GPS (Global Positioning System) or total station to obtain information on civil work areas. However, these methods are difficult to implement in inaccessible areas. Therefore, the aim of this paper is to use the UAV (Unmanned Aerial Vehicle) to measure the earth-volume. The study area is located in a reservoir construction site in Sangju-si, Gyeongsangbuk-do, Republic of Korea. We compared the earth-volume amounts acquired by UAV-based surveying to ones acquired by total stationbased and GPS-based surveying, respectively. In the site, the amount of earth-volume acquired by GPS was 147,286.79m³. The amount of earth-volume acquired by total station was 147,286.79m3, which is the 96.13% accuracy compared to the GPS-based surveying. The earth-volume obtained by UAV was 143,997.05m when measured without GCPs (Ground Control Points), 147,251.71m³ with 4 GCPs measurement, and 146,963.81m³ with 7 GCPs measurement. Compared to the GPS-based surveying, 97.77%, 99.98%, and 99.78% accuracies were obtained from the UAV-based surveying without GCP, 4 GCPs, and 7 GCPs, respectively. Therefore, it can be confirmed that the UAV-based surveying can be used for the earth-volume measurement.