Analysis on Spatial Distribution of Check Points for Vertical Accuracy Assessment of DTM derived from UAV

The geospatial data acquisition becomes easier than before. It is due to the availability of Unmanned Aerial Vehicle (UAV) or more familiar known as a drone. However, the accuracy is still in doubt. Especially data acquired using an optical sensor mounted on the UAV. The American Society of Photogrammetry and Remote Sensing (ASPRS) standards were used for the quality guidance. Fixed-wing type of UAV was employed with the mounted optical sensor. The final result of vertical elevation generated from the optical sensor then compared with the data of terrestrial laser scanner from two different spatial distribution of checkpoint (that is even and uneven) of two different locations (that is active and inactive) of high confidence area. The accuracy assessment found that the even spatial distribution and a higher number of checkpoints of active high confidence area lead to higher vertical elevation error, while the uneven distribution and lower number of checkpoints of inactive confidence area lead to lower vertical elevation error. This study proposed that for vertical accuracy assessment, the user need to find the inactive bare-earth confidence area for quality control of DTM derived from the mounted optical sensor on UAV.