Assessment of Factors Affecting the Use of Drones in Map Production

Multi-rotor and fixed-wing drones are extensively used to collect the data needed for producing large-scale topographic maps and plans. Several types of drone products are available, and the most important one for surveyors is an orthophoto. Flight planning, the quality of the control data, the assessment of drone products, and the image processing software need to be considered when using thes e drones. In this study, we explained these concepts and discussed their theoretical and practical importance in providing standards and tools that might help drone users, surveyors, and others, in obtaining the products they desire. We also proposed a detailed methodology for evaluating the accuracy of the image processing products of the drones as aerial triangulation and orthophoto. We discussed the importance of the Ground Sampling Distance (GSD) and the ground control points to assess the absolute accuracy of the aerial triangulation of the images and the importance of performing statistical tests before evaluating the absolute horizontal accuracy of the orthophoto. The checkpoints measured using more accurate methods than drone photogrammetry were used for the assessment. In this study, we evaluated the dependence of the differences between the coordinates of these points and the coordinates of the corresponding points measured on the orthophoto based on a normal distribution, and the correlation between them, before applying international standards for determining the absolute horizontal accuracy of the orthophoto. An orthophoto covering 6.57 hectares with a horizontal accuracy of 0.362