HBIM symmetry parametrization using TLS and UAV LiDAR measurements

Abstract

The paper describes a new approach to the assessment of symmetry in HBIM datasets on the example of the Tower of Gediminas in Vilnius (Lithuania). Symmetry is a principal component of the design and construction of ancient, medieval, Renaissance, and other epochs. The unified methodology involves the processing of LiDAR point clouds and applies to objects with a regular polygon cross-section. Proposed HBIM parameters introduce a uniform description of features of symmetry of historical buildings, which provides new insights into the original design of spatial relationships between the buildings’ architectural elements useful for professional conservators and renovators. The validation of the new approach involved well-established TLS and, taking into account the current development of drone technologies, ALS measurements. The obtained converging and similar estimates showed the applicability of both LiDAR technologies. Hence, the study proposes the introduction of the new symmetry parameters into the HBIM products and software.