Terrestrial laser scan planning for bridge structures at complex sites

Terrestrial laser scanning (TLS) planning for scanning (P4S) of bridge structures in complex environments often faces challenges such as algorithm convergence issues, inefficient panoramic scanning, and time-consuming multistation registration. To address these issues, this paper proposes a universal P4S framework that integrates simulation scene generation and TLS station and target position planning. Simulation scene generation is simplified by virtual prescanning based on a three-dimensional bridge model. TLS station planning incorporates scanning angle configuration, enabling the optimized allocation of both panoramic and angular scanning stations. Target position planning considers visibility relationships among neighboring TLS stations to minimize the number of required targets. The final P4S output includes TLS stations, target positions, scan parameters, and scan plan. The effectiveness of the proposed framework is demonstrated through a field experiment on an under-construction bridge, where the total scanning time was significantly reduced from 698 minutes to 418 minutes (a reduction of approximately 40%).