5 research outputs found
Geodetic deformation measurement and analysis of the ATLAS experimental cavern at CERN
Caverns for large physics detectors, such as the one for the Large Hadron Collider experiments, sit nearly 100 m underground and measure several tens of meters in length, width and height. The deformation of the cavern base slab over decades has a direct influence on the relative alignment of detectors with respect to the accelerator. The expected long-term movements are larger than the fine adjustment of detectors and accelerators. In this paper, the measured deformations of the ATLAS experiment's main cavern floor and lateral walls over nearly 20 years have been analysed. The measurement series have been performed in various time intervals getting down to half a year. The used measurement techniques, such as the polar method (total station and laser tracker) and precise levelling, allow to obtain sub-millimetre precision. Even if the deformations are significantly (four times) lower compared to the predictions of the civil engineering consultants at the moment of the cavern construction, the measured ones reach values up to 5.0 mm for the base slab and up to 14.7 mm for the lateral walls
Ocena dok艂adno艣ci precyzyjnego pozycjonowania GNSS w czasie rzeczywistym z wykorzystaniem technologii RTX Trimble
In this paper, authors present results of accuracy verification of the Trimble RTX technology. The GNSS receiver Spectra Precision SP60 was used in Cyprus (Kato Paphos Archaeological Park). To evaluate the accuracy of the receiver, two measuring test networks (consisting of 30 and 55 control points) were established. All points were determined in four measuring cycles. Additionally, in order to make more advanced analysis of the data, the bases were also measured by using another GNSS receiver - Geomax-Zenith 25. The point positions, in this case, were conducted in the local coordinate system of Kato Paphos Archaeological Park by using RTK positioning technology. To make a comparison, it was necessary to transform the coordinates based on different groups of fitting points. Analysis allowed to conclude that the Spectra Precision SP60 receiver and the RTX Trimble technology guarantee repeatable results (on the level of 4 cm) of point positioning measurements.W artykule autorzy przedstawiaj膮 wyniki analizy dok艂adno艣ci technologii Trimble RTX. Odbiornik GNSS Spectra Precision SP60 wykorzystano podczas bada艅 na Cyprze (Park Archeologiczny Kato Pafos). Aby oceni膰 dok艂adno艣膰 odbiornika, ustalono dwie bazy testowe (sk艂adaj膮ce si臋 z 30 i 55 punkt贸w kontrolnych). Wszystkie punkty zosta艂y okre艣lone w czterech cyklach pomiarowych. Dodatkowo, w celu bardziej zaawansowanej analizy danych, pomiary zosta艂y r贸wnie偶 wykonane przy u偶yciu innego odbiornika GNSS - Geomax-Zenith 25. Pozycjonowanie w tym przypadku, zosta艂o przeprowadzone w lokalnym uk艂adzie wsp贸艂rz臋dnych parku archeologicznego Kato Pafos z wykorzystaniem technologii pozycjonowania RTK. W celu por贸wnania wynik贸w bada艅 konieczne by艂o przetransformowanie wsp贸艂rz臋dnych do jednego uk艂adu. Transformacj臋 wykonano na podstawie r贸偶nych grup punkt贸w dostosowania. Analiza otrzymanych wynik贸w pozwoli艂a stwierdzi膰, 偶e odbiornik Spectra Precision SP60 i technologia RTX Trimble gwarantuj膮 por贸wnywalne wyniki pozycjonowania (na poziomie 4 cm)
Documentation of hiking trails and wooden areas using unmanned aerial vehicles (UAV) in Tatra National Park
The research described in this article was conducted in the Tatra National Park in Poland, which is considered as one of the most-visited national parks in Europe. The exceptional popularity of this place is responsible for intensification of morphogenetic processes, resulting in the development of numerous forms of erosion. This article presents the outcomes of the research whose purpose was to verify the usability of unmanned aerial vehicles to check the condition of hiking trails and forests in alpine areas. An octocopter equipped with a non-metric camera was used for measurements. The paper sketches the methodology of data acquisition in harsh conditions and demanding locations of hiking trails on steep Tatra slopes. The paper also describes stages that lead to elaboration of basic photogrammetric products relying on SfM (Structure from Motion) technique. Finally, it shows the applicability of the prepared products to the evaluation of erosion along hiking trails, and to the study of plant succession or tree stand condition in the area located next to hiking trails
Assessment of the usefulness of unmanned aerial vehicles to inspection of erosive processes along tourist trails in terms of geomorphological mapping
Niniejszy artyku艂 jest pr贸b膮 okre艣lenia przydatno艣ci bezza艂ogowych statk贸w lataj膮cych (BSL) do opracowa艅 geomorfologicznych. Badania przeprowadzono w Tatrza艅skim Parku Narodowym (zielony szlak z My艣lenickich Turni na Kasprowy Wierch). Jest to obszar, na kt贸rym procesy morfogenetyczne zachodz膮 z du偶膮 intensywno艣ci膮. Efektem s膮 liczne formy erozyjne. Do pomiar贸w zosta艂 u偶yty wielowirnikowiec wyposa偶ony w niemetryczn膮 kamer臋 艣wiat艂a widzialnego. Pozyskane dane wykorzystano do wygenerowania wysokorozdzielczej ortofotomapy oraz numerycznego modelu pokrycia terenu (NMPT). W ramach prac terenowych przeprowadzono r贸wnie偶 kartowanie geomorfologiczne badanego obszaru. Na tej podstawie mo偶liwa by艂a ocena przydatno艣ci wygenerowanych NMPT do bada艅 geomorfologicznych oraz ich korelacja z naziemnym kartowaniem geomorfologicznym. Opieraj膮c si臋 na pozyskanych materia艂ach, podj臋to pr贸b臋 oceny skutk贸w i intensywno艣ci erozji szlak贸w turystycznych w tej cz臋艣ci Tatr. Do analiz wykorzystano wygenerowan膮 ortofotomap臋 i NMPT (dane aktualne) oraz dane archiwalne pochodz膮ce z lotniczego skanowania laserowego przeprowadzonego w 2012 r. Interpretacja ww. materia艂贸w pozwoli艂a stwierdzi膰, 偶e produkty utworzone na podstawie danych pozyskanych z BSL s膮 bardzo pomocne w opracowaniach geomorfologicznych. Korzystaj膮c z nich, mo偶na z du偶膮 dok艂adno艣ci膮 okre艣li膰 stopie艅 erozji na szlakach oraz ich zmiany przestrzenne, a tak偶e oceni膰 wizualnie i ilo艣ciowo stopie艅 przekszta艂ce艅 terenu (m.in. okre艣li膰 obj臋to艣ci usuni臋tych pokryw zwietrzelinowych i materia艂u glebowego). Mo偶liwe jest r贸wnie偶 wyci膮gni臋cie wniosk贸w o dalszym przebiegu proces贸w erozyjnych i wyznaczenie obszar贸w, kt贸re erozj膮 mog膮 by膰 obj臋te w niedalekiej przysz艂o艣ci. To z kolei pozwoli na takie planowanie przebiegu szlak贸w oraz ich remont贸w, aby zminimalizowa膰 wp艂yw antropopresji spowodowany przez wzmo偶ony ruch turystyczny.The paper is an attempt to determine the suitability of unmanned aerial vehicles (UAV) for geomorphological studies. The research was carried out in the Tatra National Park (green trail from My艣lenickie Turnie to Kasprowy Wierch). Morphogenetic processes occur with high intensity in this area and give rise to numerous erosive form. A multirotor equipped with a non-metric visible light camera was used for measurements. The acquired data was used to generate a high resolution orthophotomap and a digital surface model (DSM). As part of the in-field data capture, geomorphological mapping of the research area was carried out as well. On this basis, it was possible to assess the suitability of the generated DSM for the geomorphological research. Moreover, the correlation between the DSM and the terrestrial geomorphological mapping is evaluated. In virtue of obtained data, effects and the intensity of tourist trails erosion were assessed in this part of the Tatra Mountains. The analysis involved the orthophotomap and the DSM (current data) as well as archival data from aerial laser scanning (ALS) conducted in 2012. Interpretation of above-mentioned results allowed to conclude that the data originating from UAV is very helpful in geomorphological studies. It is possible to determine the level of trails erosion and their spatial changes with high accuracy. Furthermore it allows to assess visually and quantitatively the extend of the land transformations (e.g. determine the volume of removed rock waste and soil). In conclusion, it is also possible to prescribe the further course of erosion processes and identify areas that might be suffered by erosion in the near future. This in turn will allow to change trails planning strategy, in order to minimize the impact of anthropogenic effect caused by intensified tourist flows
First considerations on the supporting structures of FCC-ee booster and collider in the arc regions
International audienceIn 2022, the FCC Feasibility Study management mandated aworking group to analyse the best configuration of the FCC-ee tunnelin the arc regions, in view of the construction of a mock-up of thearc half-cell. One of the main and most challenging goals of thestudy, named FCC-ee Arc Half-Cell Mock-up Project, was toperform a preliminary investigation on the principles of supportingthe Short-Straight Sections and dipoles of the half-cells, both forthe booster and for the collider machines. This is an importantinput needed for the choice of the best configuration of therelative placement of the booster with respect to the collider. Thestructural stiffness, mass and stability of the supportingstructures must be optimized to minimize the vibrationstransmitted/transferred to the magnetic system of the acceleratorsby elements such as pumps, water cooling system, beamthermomechanical stresses, powering elements, etc. To perform thestudy, tools such as CAD software, FEM and analytical techniqueswere employed. This paper summarizes the preliminary design conceptsand the results of the simulations performed