Abstract: Using Topcon Sirius Sirius Pro image-free drone aerial photography system as the carrier, from the survey area route design, image data collection, product output and other technologies, combining with examples, the system's measurement accuracy and application in large-scale topographic maps are analyzed. The system breaks through the traditional low-altitude photogrammetry mode, without the need for field three measurements, and the field data can be automatically processed with one-click. Its application greatly shortens the production cycle and reduces production costs. It also proves that the system can meet the accuracy requirements of large-scale topographic map surveying and mapping.

Key words: image-free control, route design, DOM and DEM, DLG and 3D generation, accuracy