Anna Forte, Francesca Trevisiol, Giulia Fiorini, Gabriele Bitelli
Integrating geomatic high-detail surveying and thermography for the documentation of historical masonry

The integration of infrared thermography (IRT) with high-resolution 3D surveying represents an effective approach in support of non-destructive diagnostics applied to heritage materials. While there has been increasing interest in this area, the numerical incorporation of thermographic data into spatially accurate 3D models poses significant challenges, particularly when it comes to embedding quantitative temperature data directly into geometric datasets. This study introduces a structured and replicable workflow designed to facilitate this numerical integration through the generation of a thermal point cloud, wherein each 3D point is associated with corresponding temperature values. The proposed methodology was applied to a historic masonry wall at the University of Bologna, which exhibited both structural and biological deterioration, thus providing an ideal case study to test the robustness of the approach. Data acquisition was carried out using high-resolution photogrammetry, achieving a sub-millimetric Ground Sampling Distance (GSD), alongside terrestrial laser scanning (TLS) and calibrated thermographic imaging to ensure both geometric accuracy and thermal reliability. A semi-manual tie-point-based alignment approach was employed to estimate camera pose for both RGB and thermal imagery simultaneously, with scaling supported by data obtained from the laser scanning process to achieve the final integrated dataset. The resultant thermal point cloud enhances analytical potential, enabling spatially contextualized thermal diagnostics and allowing deterioration patterns to be examined in relation to accurately reconstructed geometric features. Overall, this research addresses current limitations within the field and demonstrates a scalable and adaptable framework for the integration of thermal and spatial data in the realm of architectural diagnostics, opening possibility for more advanced, data-driven conservation and monitoring practices.

Barbara Fazion, Daniele Treccani, Andrea Adami, Luigi Fregonese
High-Resolution Photogrammetric Survey of a Romanesque Mosaic Floor: A Comparative Analysis of UAS and a Custom-Built Acquisition System

The high-resolution survey of flat surfaces of significant historical and artistic value, such as decorated floors and mosaics, is a fundamental phase both for the documentation and the preservation of cultural heritage. Given the material and chromatic complexity of these objects, it is essential to obtain photogrammetric data that are accurate from both a geometric and radiometric point of view. This study compares two approaches to this task, both involving a typical photogrammetric workflow, but from two different point of view: firstly, an acquisition using a Unmanned Aerial System (UAS), and secondly, an acquisition very close to the object using a camera mounted on a prototype for mobile photographic acquisitions. This prototype is under development and already tested by the authors, which uses cross-polarisation with a camera and lighting integrated in an enclosed environment into a mobile cart. The aim is to evaluate and compare the effectiveness of two systems in terms of i) speed of acquisition, ii) ease of use, iii) metric quality, iv) level of detail, v) presence of reflections and vi) surface documentation capability.

Vincenzo Saverio Alfio, Domenica Costantino, Mathab Fallah, Alfredo Restuccia Garofalo, Massimiliano Pepe, Paolo Piumatti
Integrated Workflow for 3D Modelling of Historic Architecture: A Multi-Sensor Approach

The proposed work presents an integrated approach for the three-dimensional digitisation and parametric modelling of a historic building, specifically the Church of “Sant’Antonio dei Cappuccini”. The survey involved the combined use of photogrammetric surveys from Unmanned Aerial Vehicle (UAV) and scanning using a handheld Laser Scanner. This multi sensors approach allowed to obtain a detailed point cloud of the structure in rapid and accurate way; in addition, an advanced workflow was implemented to transform the point cloud into a Non-Uniform Rational B-Splines (NURBS) model capable of faithfully representing the complex architectural geometries. Unlike mesh models, which are based on a polygonal approximation of geometry, NURBS are based on mathematical formulas capable of producing continuous and editable surfaces with a high degree of control, maintaining a high level of accuracy compared to the original model. Therefore, this methodological approach can be replicated in different contexts, particularly for historical and architectural structures, as well as being interoperable within other workflows such as HBIM (Heritage Building Information Modelling).

Carlo Anelli, Vanessa Pellicorio, Valentina Bello, Sabina Merlo
Optical testing the compliance with regulatory standards of urea concentration in AdBlue®

This paper presents an absorption-based optical approach to check the compliance of urea concentration in AdBlue® with regulatory standards. The implemented low-cost and compact measuring system exploits two LEDs that emit in the SWIR spectral band, a glass capillary, and an amplified photodiode to detect the intensity of the radiation transmitted through the fluid under test. The functionality of the system has been demonstrated on urea–water solutions with urea concentrations from 0 up to 525 mg/mL. Thanks to the attained calibration curve, we retrieved the urea concentration of different AdBlue® samples, found in agreement with HPLC results. The proposed optical method allows to easily verify if the estimated urea concentration falls within the required range for AdBlue®.

Marialuisa Tognolina, Egidio D'Angelo
Two-photon calcium imaging experiments to investigate the properties of neuronal microcircuits: the example of cerebellar network activity

We have developed a custom-made two-photon microscope integrating a spatial light modulator that can modulate the phase of a laser beam and divide it into multiple diffraction-limited beamlets configurable in real time. We used this system to study cerebellar circuit activity and long-term synaptic plasticity expression by simultaneously acquiring stimulus-induced calcium signals from neurons located in different cerebellar layers.