Optimization of UAV Flight Parameters for Urban Photogrammetric Surveys: Balancing Orthomosaic Visual Quality and Operational Efficiency

Unmanned Aerial Vehicles are increasingly used for urban photogrammetry, yet best-practice guidance on flight-planning parameters in dense city blocks remains limited. However, the quality of generated orthomosaics is strongly dependent on the proper configuration of flight parameters, highlighting the need for evidence-based guidance in consolidated urban environments. This study evaluated the impact of various flight configurations on orthomosaic visual quality and operational efficiency. A total of 96 automated flights were conducted over a 1.5-hectare urban area, systematically varying height, frontal overlap, lateral overlap, camera angle, and flight pattern. Orthomosaic photogrammetric reconstructions were generated and assessed using a multi-criteria scoring system based on the image processing time and the visual clarity of control targets. Results show that a flight height of 60 m, 70% frontal overlap, 80% lateral overlap, nadir 90° camera angle, and a grid flight pattern provide the best balance between image quality and operational efficiency. Lower heights improved visual detail but increased processing time, while excessive overlaps did not necessarily enhance final image quality.