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Heritage sites are affected by many factors that cause degradation and decay over time, such as soil deformation, changes in weather conditions, or excess moisture, which can cause damages to historical sites. For this reason, restoration works are planned and carried out to preserve the object's existing condition, renovate and repair the damaged parts, or restore the original condition of the object. The Rescue Project was undertaken in the Blessed Ladislas' chapel in St. Anna's Church in Warsaw, Poland. The main goal of the planned work was to restore the original rococo character of the dome paintings. The aim of this article was to present the integration of the multi-temporal conservation work and non-invasive measurements for changes analysis during conservation works. For this purpose, point clouds acquired with a Z+F 5006h ground-based scanner and images captured via Structure-from-Motion and MultiView Stereo method implemented in Agisoft Metashape software were used. The proposed conservation analysis method was a multi-stage process that involved: (1) automatic data integration using a feature-based approach based on 2D detectors and point clouds converted to spherical images, (2) generalisation and harmonisation of source data, and (3) analysis of deviations between point clouds. Having registered point clouds with each other, it was possible to analyse changes that occurred during conservation work. Calculated distances between both point clouds show the localisation of cracks and damages and enable measure of the size and depth of crevices on the dome wall. [ABSTRACT FROM AUTHOR]

Nowadays, cultural heritage is an integral part of modern societies and it is necessary to preserve the tangible and intangible evidences of the past. Cultural heritage objects and sites are being devastated by natural causes and human acts. There are many existing techniques for structural health monitoring, but in the cultural heritage area, there is a need for a non-destructive measurements. The main advantages and drawbacks of some of these technologies have been presented for both laser scanner and photogrammetry techniques. The aim of this article is to present the integration of existing methods for spatial documentation (classical surveying, laser scanner, photogrammetry) and structures health monitoring using electromagnetic spectroscopy. The multi-sensor platform was developed to characterise and analyse various building materials such as marble, sandstone and bricks. The spatial techniques were used for generation of architectural documentation and geolocalisation of the multi-sensor platform. The preliminary results demonstrated that the proposed technology enables commonly used image and rage-based surface measurements as well as measurements through the entire structure for more detailed analysis. [ABSTRACT FROM AUTHOR]

The paper presents archaeological and architectural research in the Royal Castle in Warsaw where a combination of image- and range-based 3D acquisition was applied. The area examined included excavations situated inside the Tower and near its outer western wall. The work was carried out at various periods and in different weather conditions. As part of the measurements, laser scanning was performed (with a Z+F 5006h scanner) and a series of close-range images were taken. It was important to integrate the data acquired to create a comprehensive documentation of archaeological excavations. When data was acquired from TLS together with photogrammetric data (in different measurement periods), the points' displacements were controlled and analysed. The process of orienting and processing the terrestrial images included photographs taken during the inventory of the tower (Canon 5D Mark II) and photographs provided by the Castle's employees (Canon PowerShot G5 X). Agisoft PhotoScan software was used to orient and process the terrestrial images, and LupoScan for the TLS data. In order to integrate the TLS data and the clouds of points from the photographs from the various stages, they were processed into a raster form; our own software (based on the OpenCV library and the Structure-from-Motion method) and LupoScan software were used to interconnect the multi-temporal and multi-sensor data sets. As a result of processing photographs and TLS data, point clouds in an external reference system were obtained. This data was then used to study the thickness of the walls of the Justice Court Tower, to analyse the course of the retaining wall, and to generate the orthoimages necessary for chronological analysis. [ABSTRACT FROM AUTHOR]

Camera calibration is one of the basic photogrammetric tasks responsible for the quality of processed products. The majority of calibration is performed with a specially designed test field or during the self-calibration process. The research presented in this paper aims to answer the question of whether it is necessary to use control points designed in the standard way for determination of camera interior orientation parameters. Data from close-range laser scanning can be used as an alternative. The experiments shown in this work demonstrate the potential of laser measurements, since the number of points that may be involved in the calculation is much larger than that of commonly used ground control points. The problem which still exists is the correct and automatic identification of object details in the image, taken with a tested camera, as well as in the data set registered with the laser scanner. [ABSTRACT FROM AUTHOR]