NETWORK DESIGN in CLOSE-RANGE PHOTOGRAMMETRY with SHORT BASELINE IMAGES

The avaibility of automated software for image-based 3D modelling has changed the way people acquire images for photogrammetric applications. Short baseline images are required to match image points with SIFT-like algorithms, obtaining more images than those necessary for "old fashioned" photogrammetric projects based on manual measurements. This paper describes some considerations on network design for short baseline image sequences, especially on precision and reliability of bundle adjustment. Simulated results reveal that the large number of 3D points used for image orientation has very limited impact on network precision

BIM and GIS: WHEN PARAMETRIC MODELING MEETS GEOSPATIAL DATA

Geospatial data have a crucial role in several projects related to infrastructures and land management. GIS software are able to perform advanced geospatial analyses, but they lack several instruments and tools for parametric modelling typically available in BIM. At the same time, BIM software designed for buildings have limited tools to handle geospatial data. As things stand at the moment, BIM and GIS could appear as complementary solutions, notwithstanding research work is currently under development to ensure a better level of interoperability, especially at the scale of the building. On the other hand, the transition from the local (building) scale to the infrastructure (where geospatial data cannot be neglected) has already demonstrated that parametric modelling integrated with geoinformation is a powerful tool to simplify and speed up some phases of the design workflow. This paper reviews such mixed approaches with both simulated and real examples, demonstrating that integration is already a reality at specific scales, which are not dominated by "pure" GIS or BIM. The paper will also demonstrate that some traditional operations carried out with GIS software are also available in parametric modelling software for BIM, such as transformation between reference systems, DEM generation, feature extraction, and geospatial queries. A real case study is illustrated and discussed to show the advantage of a combined use of both technologies. BIM and GIS integration can generate greater usage of geospatial data in the AECOO (Architecture, Engineering, Construction, Owner and Operator) industry, as well as new solutions for parametric modelling with additional geoinformation

From cultural path to cultural route: A value-led risk management method for via Iulia Augusta in Albenga (Italy)

Today, the field of cultural heritage faces many challenges: cultural heritage is always at risk, the large amount of heritage information is often fragmented, climate change impacts cultural heritage and heritage recording can be time-consuming and often results in low accuracy. Four objectives, related to the challenges, were defined during this research work. It proposes a relevant value-led risk management method for cultural heritage, it identifies climate change impact on cultural heritage, it suggests a database lay-out for cultural heritage and demonstrates the potential of remote sensing tools for cultural heritage. The Via Iulia Augusta, a former Roman road in Albenga, was used as case study

Applying bim to built heritage with complex shapes: The ice house of filarete's ospedale maggiore in milan, Italy

This paper presents the development of a BIM model for a stratified historic structure characterized by a complex geometry: Filarete's Ospedale Maggiore ice house, one of the few remaining historic ice houses in Milan (Fig. 1). Filarete, a well-known Renaissance architect and theorist, planned the hospital in the 15th century, but the ice house was built two centuries later with a double-storey irregular octagonal brick structure, half under and half above ground, that enclosed another circular structure called the ice room. The purpose of the double-walled structure was to store ice in the middle and store and preserve perishable food and medicine at the outer side of the ice room. During World War II, major portions of the hospital and the above-ground section of the ice house was bombed and heavily damaged. Later, in 1962, the hospital was restored and rehabilitated into a university, with the plan to conceal the ice house's remaining structure in the courtyard, which ultimately was excavated and incorporated into a new library for the university. A team of engineers, architects, and students from Politecnico di Milano and Carleton University conducted two heritage recording surveys in 2015 and 2016 to fully document the existing condition of the ice house, resulting in an inclusive laser scanner and photogrammetric point cloud dataset. The point cloud data was consolidated and imported into two leading parametric modelling software, Autodesk Revit© and Graphisoft ArchiCAD©, with the goal to develop two BIMs in parallel in order to study and compare the software BIM workflow, parametric capabilities, attributes to capture the complex geometry with high accuracy, and the duration for parametric modelling. The comparison study of the two software revealed their workflow limitations, leading to integration of the BIM generative process with other pure modelling software such as Rhinoceros©. The integrative BIM process led to the production of a comprehensive BIM model that documented related historic data and the existing physical state of the ice house, to be used as a baseline for preventive maintenance, monitoring, and future conservation projects

THE USE OF TERRESTRIAL LASER SCANNING TECHNIQUES TO EVALUATE INDUSTRIAL MASONRY CHIMNEY VERTICALITY

Abstract. This paper presents a strategy to measure verticality deviations (i.e. inclination) of tall chimneys. The method uses laser scanning point clouds acquired around the chimney to estimate vertical deviations with millimeter-level precision. Horizontal slices derived from the point cloud allows us to inspect the geometry of the chimney at different heights. Two methods able to estimate the center at different levels are illustrated and discussed. A first solution is a manual approach that uses traditional CAD software, in which circle fitting is manually carried out through point cloud slices. The second method is instead automatic and provides not only center coordinates, but also statistics to evaluate metric quality. Two case studies are used to explain the procedures for the digital survey and the measurement of vertical deviations: the chimney in the old slaughterhouse of Piacenza (Italy), and the chimney in Leonardo Campus at Politecnico di Milano (Italy).</p

AUTOMATED AND ACCURATE ORIENTATION OF COMPLEX IMAGE SEQUENCES

The paper illustrates an automated methodology capable of finding tie points in different categories of images for a successive orientation and camera pose estimation procedure. The algorithmic implementation is encapsulated into a software called ATiPE. The entire procedure combines several algorithms of both Computer Vision (CV) and Photogrammetry in order to obtain accurate results in an automated way. Although there exist numerous efficient solutions for images taken with the traditional aerial block geometry, the complexity and diversity of image network geometry in close-range applications makes the automatic identification of tie points a very complicated task. The reported examples were made available for the 3D-ARCH 2011 conference and include images featuring different characteristics in terms of resolution, network geometry, calibration information and external constraints (ground control points, known distances). In addition, some further examples are shown, that demonstrate the capability of the orientation procedure to cope with a large variety of block configurations

AUTOMATIC REGISTRATION OF MULTI-SOURCE MEDIUM RESOLUTION SATELLITE DATA

Multi-temporal and multi-source images gathered from satellite platforms are nowadays a fundamental source of information in several domains. One of the main challenges in the fusion of different data sets consists in the registration issue, i.e., the integration into the same framework of images collected with different spatial resolution and acquisition geometry. This paper presents a novel methodology to accomplish this task on the basis of a method that stands out from existing approaches. The whole data (time series) set is simultaneously co-registered with a two-dimensional multiple Least Squares adjustment with different geometric transformations implemented. Some tests were carried out with different geometric transformation models (including similarity, affine, and polynomial) and variable matching thresholds. They showed a sub-pixel precision after the computation of multiple adjustment. The use of multi-image corresponding points allowed the improvement of the registration accuracy and reliability of a time series made up of data imaged with different sensors

Procedures for condition mapping using 360° images

The identification of deterioration mechanisms and their monitoring over time is an essential phase for conservation. This work aimed at developing a novel approach for deterioration mapping and monitoring based on 360° images, which allows for simple and rapid data collection. The opportunity to capture the whole scene around a 360° camera reduces the number of images needed in a condition mapping project, resulting in a powerful solution to document small and narrow spaces. The paper will describe the implemented workflow for deterioration mapping based on 360° images, which highlights pathologies on surfaces and quantitatively measures their extension. Such a result will be available as standard outputs as well as an innovative virtual environment for immersive visualization. The case of multi-temporal data acquisition will be considered and discussed as well. Multiple 360° images acquired at different epochs from slightly different points are co-registered to obtain pixel-to-pixel correspondence, providing a solution to quantify and track deterioration effects

3D MODELING FROM GNOMONIC PROJECTIONS

The paper presents a strategy able to derive and process high resolution images created by means of gnomonic projections. The implemented pipeline can be split into two phases: first, the sensor resolution of the camera is physically increased by acquiring and merging a set of images with a rotating camera equipped with a long focal lens; then the new set of gnomonic projections is processed with a 3D reconstruction methodology able to deal with very large images. Several issues are addressed in the paper, starting from image acquisition up to 3D modelling. Gnomonic projections have been demonstrated to be powerful tools when traditional pinhole images do not allow the reconstruction of small and fine details. Examples and comparisons aimed at determining the correctness of the mathematical approach for image orientation are illustrated as well

Building information modelling – A novel parametric modeling approach based on 3D surveys of historic architecture

Building Information Modelling (BIM) appears to be the best answer to simplify the traditional process of design, construction, management and maintenance. On the other hand, the intricate reality of the built heritage and the growing need to represent the actual geometry using 3D models collide with the new paradigms of complexity and accuracy, opening a novel operative perspective for restoration and conservation. The management of complexity through BIM requires a new management approach focused on the development of improve the environmental impact cost, reduction and increase in productivity and efficiency the Architecture, Engineering and Construction (AEC) Industry. This structure is quantifiable in morphological and typical terms by establishing levels of development and detail (LoDs) and changes of direction (ReversLoDs) to support the different stages of life cycle (LCM). Starting from different experiences in the field of HBIM, this research work proposes a dynamic parametric modeling approach that involves the use of laser scanning, photogrammetric data and advanced modelling for HBIM