Development of an Open-Source Tool for UAV Photogrammetric Data Processing

Unmanned aerial vehicles (UAVs) or drones are lightly weighted platforms with numerous advantages and can acquire very high-resolution data rapidly with less expenditure. However, the processing of very high-resolution data acquired through the sensors mounted on the UAV platform is a major challenge, and the commercial UAV data processing software is expensive. These software packages require high-configuration hardware and follow the general workflow of conventional photogrammetric approach for image alignment, point cloud generation, mesh generation, DSM, and ortho-mosaic generation. The integration of computer vision algorithms into digital photogrammetric techniques has made it possible to process the high-resolution datasets quickly. A wide variety of open-source software utilities are available that can perform these tasks individually; however, an integrated solution is always desirable. An attempt is made to develop an open-source tool for photogrammetric processing of UAV data using open-source libraries in Python. The software provides a complete workflow for photogrammetric processing of UAV data ranging from camera calibration, point cloud generation from selective frames based on B/H ratio, direct georeferencing of generated point cloud and digital elevation model (DEM) generation. The developed software is compatible with both 32-bit and 64-bit operating systems and low configuration hardware.