•SfM and TLS point clouds can be used for 3D modelling of heritage sites.•TLS point clouds are more accurate than SfM point clouds.•3D vector models are more versatile than 3D mesh models for ...heritage documentation.•3D vector models should be combined with elements of 3D mesh models.•Any point cloud can be a base for a 3D reality mesh model.
Technological development of remote sensing and computer graphic techniques resulted in various methods of documenting heritage sites. This paper presents validation of point clouds produced using different measurement techniques: SfM (based on images taken with a hand-held digital camera and from a UAV) and TLS and its products – a textured 3D vector model and a reality mesh. The study area is the ruins of the Church of the Annunciation of the Blessed Virgin Mary of Mount Carmel in Zagórz, Poland. The obtained results allowed for formulating general conclusions regarding the usage of particular methods for documenting heritage sites, achievable measurement accuracies and data quality. Possible further applications of produced models in VR and BIM were discussed. Based on the analyses, the research also proposes workflow for inventory of heritage sites, which may become useful during documentation surveys and modelling planning.
In recent years, Building Information Model (BIM) has become a leading topic for construction-related fields. This technology may be viewed as a process, a type of database, a software or even a 3D ...model, but in fact, it integrates all these roles and many more. Heritage (Historic) Building Information Model (HBIM) is a standard for heritage objects. It not only allows for the storing of spatial information and metadata but also provides the means of documenting changes that such structures undergo. The scope of application varies from simple documentation repository, through conservation planning tools, to construction and renovation simulation instruments. In this paper, we focus on the example of the so-called Wang Temple in Karpacz, Poland. This object was chosen due to its unique history. This project was done in cooperation with BIMPoint Company (Kraków). It was aimed at showing how effective HBIM can be in accurate spatial documentation of small-scale heritage sites.
The Earth’s surface is under permanent alteration with the area of some nations growing or shrinking due to natural or man-made processes, for example sea level change. Here, based on the NUVEL 1A ...model, we forecast (in 10, 25, and 50 years) the changes in area for countries that are located on the border of the major tectonic plates. In the analysis we identify countries that are projected to gain or lose land due to the tectonic plate movement only. Over the next 50 years, the global balance of area gains (0.4 km2) and losses (12.7 km2) is negative. Thus, due to the movements of lithospheric plates, the land surface of the Earth will decrease by 12 km2 in 50 years. Overall, the changes are not that spectacular, as in the case of changes in sea/water levels, but in some smaller countries, projected losses exceed a few thousand square metres a year, e.g., in Nepal the losses exceed 10,000 m2 year−1. Methodologically, this paper finds itself between metric analysis and essay, trying to provoke useful academic discussion and incite educators’ interests to illustrate to students the tectonic movement and its force. Limitations of the used model have been discussed in the methodology section.
With the advent of the Global Navigation Satellite System (GNSS), the need for precise and highly accurate orbit and clock products becomes crucial in processing GNSS data. Clocks in GNSS ...observations form the basis of positioning. Their high quality and stability enable high accuracy and the reliability of the obtained results. The clock modelling algorithms are continuously improved; thus, the accuracy of the clock products is evolving. At present, 8 Analysis Centers (ACs) contribute to the International GNSS Service final clock products. These products are based on GNSS observations on a network of reference stations, where for a given day one of the reference station clocks is the reference clock. In this paper, the authors determined the impact of the reference clock on the quality of clock product, especially outliers, for the first time. For this purpose, the multi-GNSS final clock products provided by the Center for Orbit Determination in Europe (CODE) for the period 2014–2021 (1773–2190 GPS week, 2921 days) were analysed. Analysis shows that by applying the Median Absolute Deviation (MAD) algorithm for outlier detection, the Passive Hydrogen Maser (PHM) clock installed on board the GALILEO satellites have the lowest level of noise, whereas the Block IIR GPS satellite launched in 1999 appears to have the highest levels of noise. Furthermore, the GNSS station OHIE3, when used as a reference clock, generates an increase in the level of noise, especially noticeable on the G09 and E03 satellites.
Spoil tips are anthropomorphic terrain structures built out of leftover materials from underground or open pit mining. Usually the term spoil tips refers to those build out of unusable particles from ...coal exploration. As such they consist mostly of slate and various types of sandstone or mudstone. But also include some amount of coal and, what is more important, coal dust. Fires of spoil tips are dangerous to the environment and humans. They can cause degradation of air, and water qualities. Sometimes degradation to the environment can be irreversible. The presented survey was done in two stages. the first included creating a general terrain model. This was done with the use of long range laser scanner. The second step was a more detailed analysis of spatial and temperature conditions. Two measuring seasons ware performed. The first included a survey made with a short range laser scanner and a hand-held inferred camera. The obtained point cloud was supplemented with temperature value with the use of software and hardware provided by the authors. The visualization of 3D discreet thermal model was done in Bentley MicrioStation. The second included a usage of Z+F IMAGER 5010 laser scanner equipped with T-Cam Rev 1.0 thermal camera insole. A new and unique device that connects laser scanner with infrared camera. This season also provide a point cloud with attached temperature value of measured points. This article provides the description of those two methods including a comparison of their effectiveness and costs. It also describes the heat conditions occurring on spoil tip of Lubelski Węgiel "Bogdanka" S.A coal mine surveyed in December 2015.
•Structure-from-motion glacier monitoring provides more 3D data than other methods.•Limited placement of ground control points is key in planning glacier monitoring.•Limited number of ground control ...points is important in planning glacier monitoring.•Structure-from-motion allows for detailed small time-step, glacier mechanics study.
Measurement of the geometry of marine-terminating glaciers is challenging due to the lack of stable ground areas in close proximity to the glacier. This precludes the use of fixed measuring devices and restricts the placement of ground control points. We propose a measurement procedure for marine-terminating glaciers using structure-from-motion including proper survey planning, control point design and model alignment. As a case study, we surveyed Hans Glacier, Hornsund fjord, South Spitsbergen. We demonstrate that our method is indeed effective for documentation of small-scale glacier dynamics, show the importance of appropriate alignment strategies for models with poorly distributed control points and compare two SfM tools (Agisoft Metashape and Bentley ContextCapture) concluding that ContextCapture offers around 17% lower error, 25% faster processing and better reconstruction of fine details and shadowed concavities.
Most of the historical sites of the Svalbard Archipelago comprise remains of whaling stations, trappers' huts and mining activities. Although most parts of Svalbard lie within the boundaries of ...national parks, not all cultural remains have been thoroughly documented and catalogued. The rapid development of modelling software allows for (re-)creating the shapes of some of these historical objects in three-dimensional (3D) computer space, for use in research, education and cultural heritage conservation. Ideally, a database of 3D vector shapes representing various historical sites would be made available as an open-access resource. This article shows how such a database could be started. During the summer of 2015, a 3D inventory of the remains at some historical sites in north-western Wedel Jarlsberg Land, Svalbard, was performed with the use of a Leica C10 laser scanner. One was a mining building at a site known as Camp Asbestos, in Asbestodden, in inner Recherchefjorden. Later, data on its history were gathered and a 3D digital reconstruction was done. The end result consists of: (1) a model of the building in its current ruined state; (2) a model of the assumed shape around the time of asbestos mining activities in 1921; and (3) documented changes in its shape between those time periods. We plan to perform similar documentation for other scanned objects and make all the data available via an open-access web server.
Landscape archaeology (archaeogeography) is a multidisciplinary study used by prehistorical, classic, and historical archaeologists. Archaeogeography deals with the study of how people have shaped ...and used their environment throughout history. It focuses on the relationship between the material culture of a given community and the changes it introduces in its spatial environment. Traditionally search for archaeological sites is mainly carried out using surface research, i.e., observation of ploughed fields in spring and autumn. However, the percentage ratio of the area covered by forests to the total area of the countries can reach up to even several dozen per cent. This is where archaeogeography aided with modern remote sensing data and processing techniques can be most useful. In this article, the authors describe the problems occurring while searching for anthropological objects in forest areas. In this first part of the two-part series, the authors present a non-invasive method based on widely available remote sensing and historical data that can be used for remote prospection or archaeological sides. The authors also present methods of field verification and critically describe the limitations and advantages of this method.
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