DATA INTEGRATION OF PHOTOGRAMMETRIC AND LASER-VISUAL-INERTIAL ODOMETRY BASED SENSORS IN THE METRIC SURVEY OF CULTURAL HERITAGE

Recent developments in the metric survey methods and techniques in the field of Geomatics are increasingly favouring the integration of data obtained from different sensors. Range-based techniques on one hand and image-based techniques on the other are complementary whenever a specific metric documentation is required, with high level of detail and accuracy. Over the last years, there has been a consolidation of the SLAM (Simultaneous Localization and Mapping) technology and its growing diffusion. With the aim of evaluating strengths and weaknesses of systems that use this technology, this contribution intends to compare some acquired datasets, with different modalities and sensors, in a context of rapid mapping of cultural assets. Specifically, the laser-visual-inertial odometry platform Kaarta STENCIL was tested and its products were compared with those obtained a terrestrial laser scanner, used as a ground truth. Furthermore, given the limitations of range-based systems in the acquisition of radiometric data of reasonable quality, suitable for texturing processes, the data obtained from the STENCIL Kaarta have been integrated with those acquired by terrestrial and aerial photogrammetry: this has allowed to associate the photogrammetric radiometric component to the geometric one acquired by the Kaarta system. It has therefore been shown that an integration of image-based technologies with range-based technologies is an effective compromise between acquisition time and quality of the generated 3D products; the possibility offered by the employed devices and technologies allow to obtain, within a rapid mapping approach, suitable data for the documentation and the study of cultural heritage.