Assessment of the accuracy of two UAVs images obtained by Ux5 and Aibotix types

Abstract

Unmanned Aerial Vehicles (UAVs) have made it possible to obtain images for all types of mapping data in fast and economic way. However, it is necessary to know the accuracy of the data and if it is within the allowable limits. This study aims to compare the accuracy of digital surface model (DSM) for an area that is derived from using two UAVs types. Ux5 and Aibotix. Both UAVs were used to obtain coordinates of reference points in order to determine the accuracy of the imagery produced from them. The coordinates were compared two times, one from the imagery acquired with a digital camera on board(Ux5) and second from imagery acquired withal digital camera on board Aibotix type. The UAVs flight height was100 m above ground. Twelve ground control points (G.C.Ps)marked by checkerboard mat were considered for data comparison. The horizontal coordinates (E,N) were obtained from the other rectified images derived from the two UAV types. The reference coordinates of the G.C. Paused for comparison were determinedly using G.P.S Leica Viva GNSS receiver with horizontal accuracy of (±3mm + 0.1ppm).The RMSE found to be σ∆E=±1.85cm and, σ∆N=±2.58cm for easting and northing respectively with total RMSE = ±3.17cmfor the Ux5, and found to be σ∆E=±2.15cm and, σ∆N=±3.67cm with total RMSE = ±4.25cm for the Aibotix. According to standards of American Society for Photogrammetric and Remote Sensing (ASPRS)andNational Standard for Spatial Data Accuracy2014(NSSDA),the horizontal accuracy for both Ux5 and Aibotix reported at the 95% confidence level can be categorized as class I and class II respectively. That indicate that the image obtained from Ux5 is more precise than Aibotix one.