scholarly journals Integrated Geophysics and Geomatics Surveys in the Valley of the Kings

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1552 ◽  
Author(s):  
Francesco Porcelli ◽  
Luigi Sambuelli ◽  
Cesare Comina ◽  
Antonia Spanò ◽  
Andrea Lingua ◽  
...  

Recent results within the framework of the collaborative project The Complete Geophysical Survey of the Valley of the Kings (VOK) (Luxor, Egypt) are reported in this article. In October 2018, a team of geomatics and geophysics researchers coordinated by the Polytechnic University of Turin worked side by side in the VOK. Topographic measurements in support of geophysical surveys and the achievement of a very large-scale 3D map of the Eastern VOK were the two main objectives of the geomatics campaign. Innovative 3D metric technologies and methods, based on terrestrial laser scanning (both static and mobile) and close-range photogrammetry were employed by the Geomatics team. The geophysical campaign focused on the acquisition of Electrical Resistivity Tomography (ERT), Ground Penetrating Radar (GPR) and high spatial density Geomagnetic (GM) data. ERT new data around KV62, both inverted in 2D sections and added to the previous ones to perform a new global 3D inversion, confirm the previous results showing both conductive and resistive anomalies that have to be explained. GPR timeslices showed some interesting features in the area in front of the KV2 entrance where GM gradient map also presents localized anomalies. In the area SSW of the KV2 the GM gradient maps evidenced also a large semicircular anomaly which, up to now, has no explanation. The potentialities of using magnetic techniques as a complement to other non-invasive techniques in the search for structures of archeological significance have been explored. The application of modern and innovative methods of 3D metric survey enabled to achieve a complete 3D mapping of what is currently visible in the valley. The integration of 2D/3D mapping data concerning visible elements and hypothetical anomalies, together with the recovering in the same global reference system of underground documentation pertaining to the Theban Mapping Project, prefigure the enhancement of multi-temporal site representation. This strategy enables the fruition development of the already discovered archaeological heritage, using modern criteria of valorization and conservation.

Author(s):  
A. Bocheńska ◽  
J. Markiewicz ◽  
S. Łapiński

<p><strong>Abstract.</strong> 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.</p>


2021 ◽  
Vol 13 (3) ◽  
pp. 452
Author(s):  
Xue Chen ◽  
Vladimiro Achilli ◽  
Massimo Fabris ◽  
Andrea Menin ◽  
Michele Monego ◽  
...  

Mass movements represent a serious threat to the stability of human structures and infrastructures, and cause loss of lives and severe damages to human properties every year worldwide. Built structures located on potentially unstable slopes are susceptible to deformations due to the displacement of the ground that at worst can lead to total destruction. Synthetic aperture radar (SAR) data acquired by Sentinel-1 satellites and processed by multi-temporal interferometric SAR (MT-InSAR) techniques can measure centimeter to millimeter-level displacement with weekly to monthly updates, characterizing long-term large-scale behavior of the buildings and slopes. However, the spatial resolution and short wavelength weaken the performance of Sentinel-1 in recognizing features (i.e., single buildings) inside image pixels and maintaining the coherence in mountainous vegetated areas. We have proposed and applied a methodology that combines Sentinel-1 interferometry with ground-based geomatics techniques, i.e., global navigation satellite system (GNSS), terrestrial laser scanning (TLS) and terrestrial structure from motion photogrammetry (SfM), for fully assessing building deformations on a slope located in the north-eastern Italian pre-Alps. GNSS allows verifying the ground deformation estimated by MT-InSAR and provides a reference system for the TLS and SfM measurements, while TLS and SfM allow the behavior of buildings located in the investigated slope to be monitored in great detail. The obtained results show that damaged buildings are located in the most unstable sectors of the slope, but there is no direct relationship between the rate of ground deformation of these sectors and the temporal evolution of damages to a single building, indicating that mass movements cause the displacement of blocks of buildings and each of them reacts differently according to its structural properties. This work shows the capability of MT-InSAR, GNSS, TLS and SfM in monitoring both buildings and geological processes that affect their stability, which plays a key role in geohazard analysis and assessment.


Author(s):  
Mariusz Drzewiecki ◽  
Maciej Kurcz ◽  
Joanna Ciesielska ◽  
Tomasz Michalik ◽  
Ewa Czyżewska-Zalewska ◽  
...  

AbstractRecent research at Soba focuses on the tangible and intangible heritage of the medieval capital of Alwa kingdom, whose remains cover approximately 275 ha. About 222 ha of this area has been built up or transformed into agricultural land in the past 30 years. An ethnographic survey was also carried out in the built-up area to understand how the residents engage with the archaeological heritage and material remains. The undeveloped area of the capital (53 ha) was the focus of interdisciplinary archaeological fieldwork conducted in 2019 and 2020. A large-scale geophysical survey, using a fluxgate gradiometer and ground-penetrating radar, was initiated in the undeveloped area, and excavation trenches were opened to verify distinctive magnetic anomalies. Along with the ethnographic and geophysical data, the study of the pottery, burials, and stratigraphic sequence (supplemented with radiocarbon dates) provides new insights into the spatial organization of the medieval capital.


2021 ◽  
Vol 13 (11) ◽  
pp. 2063
Author(s):  
Luka Jurjević ◽  
Mateo Gašparović ◽  
Xinlian Liang ◽  
Ivan Balenović

Digital terrain models (DTMs) are important for a variety of applications in geosciences as a valuable information source in forest management planning, forest inventory, hydrology, etc. Despite their value, a DTM in a forest area is typically lower quality due to inaccessibility and limited data sources that can be used in the forest environment. In this paper, we assessed the accuracy of close-range remote sensing techniques for DTM data collection. In total, four data sources were examined, i.e., handheld personal laser scanning (PLShh, GeoSLAM Horizon), terrestrial laser scanning (TLS, FARO S70), unmanned aerial vehicle (UAV) photogrammetry (UAVimage), and UAV laser scanning (ULS, LS Nano M8). Data were collected within six sample plots located in a lowland pedunculate oak forest. The reference data were of the highest quality available, i.e., total station measurements. After normality and outliers testing, both robust and non-robust statistics were calculated for all close-range remote sensing data sources. The results indicate that close-range remote sensing techniques are capable of achieving higher accuracy (root mean square error < 15 cm; normalized median absolute deviation < 10 cm) than airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) data that are generally understood to be the best data sources for DTM on a large scale.


2020 ◽  
Vol 12 (21) ◽  
pp. 3571
Author(s):  
Juan Moyano ◽  
Juan Enrique Nieto-Julián ◽  
David Bienvenido-Huertas ◽  
David Marín-García

The 3D digitization and Building Information Modeling (BIM), which is based on parametric objects, have considerably advanced by developing massive data capture techniques. Thus, reverse engineering currently plays a major role as these technologies capture accurately and efficiently the geometry, color and textures of complex architectural, archaeological and cultural heritage. This paper aims to validate close-range Structure from Motion (SfM) for heritage by analyzing the point density and the 3D mesh geometry in comparison with Terrestrial Laser Scanning (TLS). The accuracy of the results and the geometry mainly depends on the processing performed on the point set. Therefore, these two variables are significant in the 3D reconstruction of heritage buildings. This paper focuses on a 15th century case study in Seville (Spain): the main façade of Casa de Pilatos. Ten SfM surveys were carried out varying the capture method (simple and stereoscopic) and the number of shots, distances, orientation and procedure. A mathematical analysis is proposed to verify the point spatial resolution and the accuracy of the 3D model geometry by section profiles in SfM data. SfM achieved acceptable accuracy levels to generate 3D meshes despite disordered shots and the number of images. Hence, stereoscopic photography using new instruments improved the results of close-range photogrammetry while reducing the required number of photographs.


2017 ◽  
Vol 8 (16) ◽  
pp. 83 ◽  
Author(s):  
Filiberto Chiabrando ◽  
Antonia Spanò ◽  
Giulia Sammartano ◽  
Lorenzo Teppati Losè

This paper discusses some enhancements concerning 3D modelling, and the integration and comparison of 3D data from aerial and terrestrial sensors, developed by innovative geomatics techniques around the metric documentation of cultural heritage. In archaeology, it is interesting to deal with the considerable advantages of new multi-sensor approaches for the data acquisition and the management phases in terms of the sustainability (automated acquisition, quickness, precision, time and cost cutting). In particular, Unmanned Aerial Vehicles(UAVs)photogrammetry with the joint use of nadir and oblique cameras can be usefully combined with the large-scale details acquired by the terrestrial Light Detection and Ranging (LiDAR)in vast areas or complex objects, especially in mostly vertical sized objects. Here, we will report the results of an integrated 3D survey in an archaeological context in the Piedmont region of Italy. The Hercules Fountain is located in the gardens of the Venaria Reale (a Savoy Royal Palace included in the UNESCO heritage list) and has witnessed several events and historical phases during the past centuries–from its construction in the 16thcentury to its disuse and decline in the 17thcentury, right up to the 21stcentury when it was eventually brought back to light. The goal of the test is the creation of a3D continuous model of the site for documentation purposes, future consolidation, and enhancement projects finalised fora public promotion. To meet these strategic aims, a terrestrial laser scanning (TLS henceforth) survey has been designed together with multi-flights by a multi-rotor UAV and terrestrial close-range photogrammetry (CRP) acquisition to produce a highly detailed 3D textured model from which we have inferred standard 2D drawings, digital orthoimages, and further 3D products. In conclusion, the entire workflow and the outputs have been compared together to evaluate the effectiveness of each elaboration according to the different goals of the survey.


Author(s):  
N. Soulakellis ◽  
S. Chatzistamatis ◽  
C. Vasilakos ◽  
G. Tataris ◽  
A. Papakonstantinou ◽  
...  

<p><strong>Abstract.</strong> The aim of this paper is to present the methodology followed and the results obtained by the synergistic exploitation of geo-information methods towards 3D mapping of the impact of the catastrophic earthquake of June 12th 2017 on the traditional settlement of Vrisa on the island of Lesvos, Greece. A campaign took place for collecting: a) more than 150 ground control points using an RTK system, b) more than 20.000 high-resolution terrestrial and aerial images using cameras and Unmanned Aircraft Systems and c) 140 point clouds by a 3D Terrestrial Laser Scanner. The Structure from Motion method has been applied on the high-resolution terrestrial and aerial photographs, for producing accurate and very detailed 3D models of the damaged buildings of the Vrisa settlement. Additionally, two Orthophoto maps and Digital Surface Models have been created, with a spatial resolution of 5&amp;thinsp;cm and 3&amp;thinsp;cm, respectively. The first orthophoto map has been created just one day after the earthquake, while the second one, a month later. In parallel, 3D laser scanning data have been exploited in order to validate the accuracy of the 3D models and the RTK measurements used for the geo-registration of all the above-mentioned datasets. The significant advantages of the proposed methodology are: a) the coverage of large scale areas; b) the production of 3D models having very high spatial resolution and c) the support of post-earthquake management and reconstruction processes of the Vrisa village, since such 3D information can serve all stakeholders, be it national and/or local organizations.</p>


2020 ◽  
Vol 11 (1) ◽  
pp. 44
Author(s):  
Sergej Medved ◽  
Daša Krapež Tomec ◽  
Angela Balzano ◽  
Maks Merela

Since invasive alien species are one of the main causes of biodiversity loss in the region and thus of changes in ecosystem services, it is important to find the best possible solution for their removal from nature and the best practice for their usability. The aim of the study was to investigate their properties as components of wood-plastic composites and to investigate the properties of the wood-plastic composites produced. The overall objective was to test the potential of available alien plant species as raw material for the manufacture of products. This would contribute to sustainability and give them a better chance of ending their life cycle. One of the possible solutions on a large scale is to use alien wood species for the production of wood plastic composites (WPC). Five invasive alien hardwood species have been used in combination with polyethylene powder (PE) and maleic anhydride grafted polyethylene (MAPE) to produce various flat pressed WPC boards. Microstructural analyses (confocal laser scanning microscopy and scanning electron microscopy) and mechanical tests (flexural strength, tensile strength) were performed. Furthermore, measurements of density, thickness swelling, water absorption and dimensional stability during heating and cooling were carried out. Comparisons were made between the properties of six WPC boards (five alien wood species and mixed boards). The results showed that the differences between different invasive alien wood species were less obvious in mechanical properties, while the differences in sorption properties and dimensional stability were more significant. The analyses of the WPC structure showed a good penetration of the polymer into the lumens of the wood cells and a fine internal structure without voids. These are crucial conditions to obtain a good, mechanically strong and water-resistant material.


2021 ◽  
Vol 13 (2) ◽  
pp. 228
Author(s):  
Jian Kang ◽  
Rui Jin ◽  
Xin Li ◽  
Yang Zhang

In recent decades, microwave remote sensing (RS) has been used to measure soil moisture (SM). Long-term and large-scale RS SM datasets derived from various microwave sensors have been used in environmental fields. Understanding the accuracies of RS SM products is essential for their proper applications. However, due to the mismatched spatial scale between the ground-based and RS observations, the truth at the pixel scale may not be accurately represented by ground-based observations, especially when the spatial density of in situ measurements is low. Because ground-based observations are often sparsely distributed, temporal upscaling was adopted to transform a few in situ measurements into SM values at a pixel scale of 1 km by introducing the temperature vegetation dryness index (TVDI) related to SM. The upscaled SM showed high consistency with in situ SM observations and could accurately capture rainfall events. The upscaled SM was considered as the reference data to evaluate RS SM products at different spatial scales. In regard to the validation results, in addition to the correlation coefficient (R) of the Soil Moisture Active Passive (SMAP) SM being slightly lower than that of the Climate Change Initiative (CCI) SM, SMAP had the best performance in terms of the root-mean-square error (RMSE), unbiased RMSE and bias, followed by the CCI. The Soil Moisture and Ocean Salinity (SMOS) products were in worse agreement with the upscaled SM and were inferior to the R value of the X-band SM of the Advanced Microwave Scanning Radiometer 2 (AMSR2). In conclusion, in the study area, the SMAP and CCI SM are more reliable, although both products were underestimated by 0.060 cm3 cm−3 and 0.077 cm3 cm−3, respectively. If the biases are corrected, then the improved SMAP with an RMSE of 0.043 cm3 cm−3 and the CCI with an RMSE of 0.039 cm3 cm−3 will hopefully reach the application requirement for an accuracy with an RMSE less than 0.040 cm3 cm−3.


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