Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13815
F. Jia, D. Lichti, R. Shor, Arsh Khawaja, Min Kang, Max Kepler
Reservoir development in the petroleum industry starts with the drill bit. A drill bit’s dull condition must be closely monitored since it significantly influences the efficiency and the cost of drilling operations. The dull condition check procedure is called drill bit grading and is essentially a change detection problem to determine the state of the drill bit, in particular the wear of the cutting teeth inserts. Currently, the grading is conducted manually on-site, which is error-prone and highly subjective. Laser scanning technology offers a potential solution to overcome the shortcomings of existing practice. The integration of LiDAR (Light Detection and Ranging) on the newly-launched iDevices, the iPhone 12 Pro and the iPad Pro 2020 offers new opportunities for close-range measurement given their huge customer base and low cost. The goal of this research is to investigate the performance of these devices, and to develop a tool for the drill bit grading. Since bit grading is significantly impacted by the performance of the sensor, several basic tests were first conducted under controlled experimental conditions, e.g., the room temperature and ambient lighting and measurement surface. The temporal stability of the iDevices was examined by capturing a series of datasets of a flat wall over forty-five (45) minutes, then the effect of range, reflectivity and incidence angle on data quality was tested by measuring the Spectralon targets at different situations. The performance tests found that using only the LiDAR data was not sufficient for drill bit grading. Thus, a preliminary grading system based on the fusion of LiDAR and color camera is proposed by modelling the post-drilling bit and detecting the changes.
石油工业中的储层开发从钻头开始。钻头的钝化状态对钻井作业的效率和成本影响很大，因此必须密切监测。钝状态检查程序称为钻头分级，本质上是一个变化检测问题，以确定钻头的状态，特别是切削齿镶齿的磨损情况。目前，分级是现场手工进行的，容易出错，主观程度高。激光扫描技术为克服现有实践的不足提供了一种潜在的解决方案。在新推出的iPhone 12 Pro和iPad Pro 2020上集成激光雷达(光探测和测距)，为近距离测量提供了新的机会，因为它们拥有庞大的客户群和低成本。本研究的目的是研究这些装置的性能，并开发一种钻头分级工具。由于传感器的性能对钻头分级有很大影响，因此首先在可控的实验条件下进行了几项基本测试，例如室温、环境照明和测量表面。通过在45分钟内捕获一面墙的一系列数据集来检测设备的时间稳定性，然后通过测量不同情况下的Spectralon目标来测试距离、反射率和入射角对数据质量的影响。性能测试发现，仅使用激光雷达数据不足以对钻头进行分级。为此，提出了一种基于激光雷达和彩色相机融合的初步分级系统，对钻孔后的钻头进行建模并检测其变化。
{"title":"Drill bit grading using LiDAR and imagery on the apple smart devices","authors":"F. Jia, D. Lichti, R. Shor, Arsh Khawaja, Min Kang, Max Kepler","doi":"10.4995/jisdm2022.2022.13815","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13815","url":null,"abstract":"Reservoir development in the petroleum industry starts with the drill bit. A drill bit’s dull condition must be closely monitored since it significantly influences the efficiency and the cost of drilling operations. The dull condition check procedure is called drill bit grading and is essentially a change detection problem to determine the state of the drill bit, in particular the wear of the cutting teeth inserts. Currently, the grading is conducted manually on-site, which is error-prone and highly subjective. Laser scanning technology offers a potential solution to overcome the shortcomings of existing practice. The integration of LiDAR (Light Detection and Ranging) on the newly-launched iDevices, the iPhone 12 Pro and the iPad Pro 2020 offers new opportunities for close-range measurement given their huge customer base and low cost. The goal of this research is to investigate the performance of these devices, and to develop a tool for the drill bit grading. Since bit grading is significantly impacted by the performance of the sensor, several basic tests were first conducted under controlled experimental conditions, e.g., the room temperature and ambient lighting and measurement surface. The temporal stability of the iDevices was examined by capturing a series of datasets of a flat wall over forty-five (45) minutes, then the effect of range, reflectivity and incidence angle on data quality was tested by measuring the Spectralon targets at different situations. The performance tests found that using only the LiDAR data was not sufficient for drill bit grading. Thus, a preliminary grading system based on the fusion of LiDAR and color camera is proposed by modelling the post-drilling bit and detecting the changes.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"547 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126999557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13833
Ansgar Dreier, H. Kuhlmann, L. Klingbeil
The use of unmanned aerial vehicles (UAV) in monitoring applications is constantly increasing due to the improvement in sensor technology and the associated higher accuracy that can be achieved. As a result, UAV-based laser scanning is already being used in various deformation monitoring applications such as the monitoring of landslides or land deformations. The main challenges, which also limit the accuracy of the resulting georeferenced point cloud are given by the trajectory estimation, the measurement environment and the flight planning. Difficult conditions and high accuracy demands are especially given for the monitoring of a water dam. While the use of area-based measurements such as terrestrial laser scanning (TLS) is an already established approach for such monitoring tasks, the use of a similar technology on a platform such as a UAV is promising and investigated in this study by acquiring a single measurement epoch at a water dam. In addition to the proposal of a flight pattern for the measurements, the trajectory estimation results are evaluated in detail. Due to critical GNSS conditions, positioning errors lead to systematic shifts between single flight strips. Subsequent optimization with known control points allows the point cloud to be compared to a TLS reference. The difference between the two is shown to have a mean difference of 5 mm with a 9.2 mm standard deviation. This can be considered a highly promising result, especially as the potential for further improvement by using additional targets and sensors (e.g. camera) has been identified.
{"title":"The potential of UAV-based Laser Scanning for Deformation Monitoring – Case Study on a Water Dam","authors":"Ansgar Dreier, H. Kuhlmann, L. Klingbeil","doi":"10.4995/jisdm2022.2022.13833","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13833","url":null,"abstract":"The use of unmanned aerial vehicles (UAV) in monitoring applications is constantly increasing due to the improvement in sensor technology and the associated higher accuracy that can be achieved. As a result, UAV-based laser scanning is already being used in various deformation monitoring applications such as the monitoring of landslides or land deformations. The main challenges, which also limit the accuracy of the resulting georeferenced point cloud are given by the trajectory estimation, the measurement environment and the flight planning. Difficult conditions and high accuracy demands are especially given for the monitoring of a water dam. While the use of area-based measurements such as terrestrial laser scanning (TLS) is an already established approach for such monitoring tasks, the use of a similar technology on a platform such as a UAV is promising and investigated in this study by acquiring a single measurement epoch at a water dam. In addition to the proposal of a flight pattern for the measurements, the trajectory estimation results are evaluated in detail. Due to critical GNSS conditions, positioning errors lead to systematic shifts between single flight strips. Subsequent optimization with known control points allows the point cloud to be compared to a TLS reference. The difference between the two is shown to have a mean difference of 5 mm with a 9.2 mm standard deviation. This can be considered a highly promising result, especially as the potential for further improvement by using additional targets and sensors (e.g. camera) has been identified.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128686489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13822
C. Cabezas-Rabadán, J. Pardo-Pascual, J. Palomar-Vázquez, A. Fernández-Sarría
Beaches are extremely dynamic natural environments that experience significant variations at different spatial and temporal scales. The processes of appearance and maintenance of morphological features as the beach mesoforms, as well as their characterization, may provide useful information on the morphodynamic evolution of a beach and the spatial variability of nearshore processes. The high availability of Sentinel-2 satellite images together with the development of tools such as the system SHOREX allows the automatic extraction of the position of the shore. The high accuracy of the resulting satellite-derived shorelines (SDS) offers high potential for the definition of relatively detailed morphological features. This work assesses the ability to apply the SDS for characterizing beach mesoforms appearing at Cala de Mijas, in Málaga (S Spain) as well as characterising their changes over time. The extraction of the SDS enables the characterisation of rhythmic coastal forms through the undulations described by the shoreline position along the beach face by using a sinuosity index and to start to address the study of their relationship with the registered wave conditions. This proves that the information derived from mid-resolution satellite images can become a key source of information to characterize the morphological dynamics of beach environments.
海滩是极具活力的自然环境，在不同的空间和时间尺度上经历着显著的变化。作为海滩中形态的形态特征的出现和维持过程及其特征可以为海滩的形态动力学演化和近岸过程的空间变异性提供有用的信息。Sentinel-2卫星图像的高可用性以及SHOREX系统等工具的开发允许自动提取海岸位置。由此产生的卫星衍生海岸线(SDS)的高精度为定义相对详细的形态特征提供了很大的潜力。这项工作评估了应用SDS来表征Málaga(西班牙南部)Cala de Mijas出现的海滩中形态的能力，以及它们随时间变化的特征。SDS的提取可以通过使用弯曲指数沿海滩表面的海岸线位置所描述的波动来表征有节奏的海岸形式，并开始研究它们与所记录的波浪条件的关系。这证明了中分辨率卫星图像的信息可以成为表征海滩环境形态动态的关键信息来源。
{"title":"Monitoring the spatiotemporal variability of beach mesoforms by analyzing Sentinel-2 images","authors":"C. Cabezas-Rabadán, J. Pardo-Pascual, J. Palomar-Vázquez, A. Fernández-Sarría","doi":"10.4995/jisdm2022.2022.13822","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13822","url":null,"abstract":"Beaches are extremely dynamic natural environments that experience significant variations at different spatial and temporal scales. The processes of appearance and maintenance of morphological features as the beach mesoforms, as well as their characterization, may provide useful information on the morphodynamic evolution of a beach and the spatial variability of nearshore processes. The high availability of Sentinel-2 satellite images together with the development of tools such as the system SHOREX allows the automatic extraction of the position of the shore. The high accuracy of the resulting satellite-derived shorelines (SDS) offers high potential for the definition of relatively detailed morphological features. This work assesses the ability to apply the SDS for characterizing beach mesoforms appearing at Cala de Mijas, in Málaga (S Spain) as well as characterising their changes over time. The extraction of the SDS enables the characterisation of rhythmic coastal forms through the undulations described by the shoreline position along the beach face by using a sinuosity index and to start to address the study of their relationship with the registered wave conditions. This proves that the information derived from mid-resolution satellite images can become a key source of information to characterize the morphological dynamics of beach environments.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128522622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13818
N. Depountis, K. Kavoura, K. Nikolakopoulos, G. Drakatos, P. Argyrakis, P. Elias, N. Sabatakakis
Many mountainous villages have been struck by landslides in Western Greece due to growing urbanization and uncontrolled land use in landslide prone areas, without considering the engineering geological environment. The presence of the tectonically highly sheared and weathered geological formations of the alpine basement (such as flysch) and the intense geomorphological relief, strongly contribute to the periodically induced instability phenomena mainly triggered by heavy rainfalls and extreme meteorological events. The current research combines long-term monitoring of the parameters connected to the landslide activity with the real-time kinematics observation in a dense-populated mountainous village located in the Region of Epirus in Greece. The landslide movements evolve very low velocity values at different depths; thus, the landslide cases can be characterized as complex and "extremely slow". The long-term monitoring is carried out by several in-place and portable inclinometer probes that permit the detailed observation of subsurface displacements for an extended period. In addition, GNSS measurements, very high-resolution multitemporal interferometry (accompanied with the installation of corner reflectors) and Unmanned Aerial Vehicle (UAV) photogrammetric surveys are used for the monitoring of surface deformation. All instrumentation is installed in the wider area of the landslide zone and one of the main goals of this approach is to combine long-term monitoring of the parameters connected to the landslide activity with the observation of the landslide kinematics in real-time.
{"title":"Landslide monitoring using geotechnical, UAV, GNSS and MTInSAR instrumentation","authors":"N. Depountis, K. Kavoura, K. Nikolakopoulos, G. Drakatos, P. Argyrakis, P. Elias, N. Sabatakakis","doi":"10.4995/jisdm2022.2022.13818","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13818","url":null,"abstract":"Many mountainous villages have been struck by landslides in Western Greece due to growing urbanization and uncontrolled land use in landslide prone areas, without considering the engineering geological environment. The presence of the tectonically highly sheared and weathered geological formations of the alpine basement (such as flysch) and the intense geomorphological relief, strongly contribute to the periodically induced instability phenomena mainly triggered by heavy rainfalls and extreme meteorological events. The current research combines long-term monitoring of the parameters connected to the landslide activity with the real-time kinematics observation in a dense-populated mountainous village located in the Region of Epirus in Greece. The landslide movements evolve very low velocity values at different depths; thus, the landslide cases can be characterized as complex and \"extremely slow\". The long-term monitoring is carried out by several in-place and portable inclinometer probes that permit the detailed observation of subsurface displacements for an extended period. In addition, GNSS measurements, very high-resolution multitemporal interferometry (accompanied with the installation of corner reflectors) and Unmanned Aerial Vehicle (UAV) photogrammetric surveys are used for the monitoring of surface deformation. All instrumentation is installed in the wider area of the landslide zone and one of the main goals of this approach is to combine long-term monitoring of the parameters connected to the landslide activity with the observation of the landslide kinematics in real-time.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114305225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13942
M. Rahrig, J. L. Lerma
Multispectral imaging (MSI) is increasingly used for the documentation and analysis of cultural heritage. It provides conservators a powerful non-destructive technique (NDT) and non-contact tool for detecting damage, hidden features and material-specific characteristics. Hereby multispectral documentation of wall paintings in an urban environment poses special challenges for the art expert. For example, these are often large works of art located outdoors on building façades. Excitation with artificial light in well-defined spectral ranges, as should ideally be the case in MSI, is therefore often not possible. In the following, low-cost variants of MSI (ultraviolet reflectography, visible light imaging and infrared reflectography) in combination with 3D photogrammetry and statistical methods for analysing image data are tested and discussed. Hereby, a metrically correct, large-scale documentation of wall paintings with accurate superimposed images of different spectral ranges will be generated by linking the MSI data in a photogrammetric image cluster to create individual texture maps for each spectral band. Furthermore, Principal Component Analysis (PCA) is used to extract additional information from the MSI data. The case studies are located on the campus of the Universitat Politècnica de València.
{"title":"Multispectral imaging for the documentation of graffiti in an urban environment","authors":"M. Rahrig, J. L. Lerma","doi":"10.4995/jisdm2022.2022.13942","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13942","url":null,"abstract":"Multispectral imaging (MSI) is increasingly used for the documentation and analysis of cultural heritage. It provides conservators a powerful non-destructive technique (NDT) and non-contact tool for detecting damage, hidden features and material-specific characteristics. Hereby multispectral documentation of wall paintings in an urban environment poses special challenges for the art expert. For example, these are often large works of art located outdoors on building façades. Excitation with artificial light in well-defined spectral ranges, as should ideally be the case in MSI, is therefore often not possible. In the following, low-cost variants of MSI (ultraviolet reflectography, visible light imaging and infrared reflectography) in combination with 3D photogrammetry and statistical methods for analysing image data are tested and discussed. Hereby, a metrically correct, large-scale documentation of wall paintings with accurate superimposed images of different spectral ranges will be generated by linking the MSI data in a photogrammetric image cluster to create individual texture maps for each spectral band. Furthermore, Principal Component Analysis (PCA) is used to extract additional information from the MSI data. The case studies are located on the campus of the Universitat Politècnica de València. ","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127485184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13851
P. Javadi, J. L. Lerma, L. García-Asenjo
Geomonitoring of rockfalls and landslides is increasingly carried out by solutions that integrate different geomatics techniques to provide quickly 3D point clouds or models that are required to be rigorously in the same reference system. Methods based on remote sensing such as terrestrial laser scanning or photogrammetry need precise ground control, which is usually provided by means of geodetic surveys. However, when the study area is large with strong limitations due to particular orography, those geodetic techniques cannot always grant accurate target points optimally distributed within the monitored object, and only an external reference frame is available to provide absolute orientation to those 3D point clouds or models. In that case, terrestrial photogrammetry shows clear advantages compared to terrestrial laser scanning. Still, it may require a large number of high-quality images taken from well-distributed stations, thus hampering the desired fast data collection. A possible alternative to cope with this problem is the use of the panoramic photogrammetry method by using robotic devices like Gigapan along with a systematic collection procedure from stable stations of a reference frame whose coordinates are accurate and well-controlled. This contribution describes an experiment conducted in Cortes de Pallás (Spain), where an existing infrastructure consisting of 10 pillars and 15 check points is annually monitored at millimetric level, to investigate the potential of long-range panoramic photogrammetry as applied to deformation monitoring. The panoramic images were taken from 7 selected pillars using the Gigapan robotic device. The accuracy of oriented panoramic images, the performance of the method in long-ranges (500-1000 m), and the consistency with the geodetic techniques in the 15 check points were analyzed. Finally, some conclusions about the suitability of panoramic photogrammetry as applied to long-range deformation monitoring are drawn.
岩崩和滑坡的地质监测越来越多地通过集成不同地理信息技术的解决方案来实现，这些解决方案可以快速提供3D点云或模型，这些点云或模型需要严格遵循同一参考系统。基于遥感的方法，如地面激光扫描或摄影测量，需要精确的地面控制，这通常是通过大地测量来提供的。然而，当研究区域较大且受地形限制较大时，这些大地测量技术并不总能给出准确的目标点，这些目标点分布在被监测对象内，只有外部参考框架可用于提供这些三维点云或模型的绝对方向。在这种情况下，与地面激光扫描相比，地面摄影测量显示出明显的优势。然而，它可能需要从分布良好的站点拍摄大量高质量图像，从而阻碍了所需的快速数据收集。解决这个问题的一个可能的替代方案是使用全景摄影测量方法，通过使用像Gigapan这样的机器人设备，以及从稳定的参考系站进行系统的收集程序，这些参考系的坐标是精确和良好控制的。这篇文章描述了在Cortes de Pallás(西班牙)进行的一项实验，在那里，由10根柱子和15个检查点组成的现有基础设施每年进行毫米级监测，以调查远程全景摄影测量应用于变形监测的潜力。全景图像是使用Gigapan机器人设备从7个选定的柱子上拍摄的。分析了定向全景图像的精度、该方法在远距离(500 ~ 1000 m)的性能以及与15个检查点大地测量技术的一致性。最后，对全景摄影测量技术在遥感变形监测中的适用性进行了总结。
{"title":"First experiment of long-range panoramic images on a high-precision geodetic reference frame","authors":"P. Javadi, J. L. Lerma, L. García-Asenjo","doi":"10.4995/jisdm2022.2022.13851","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13851","url":null,"abstract":"Geomonitoring of rockfalls and landslides is increasingly carried out by solutions that integrate different geomatics techniques to provide quickly 3D point clouds or models that are required to be rigorously in the same reference system. Methods based on remote sensing such as terrestrial laser scanning or photogrammetry need precise ground control, which is usually provided by means of geodetic surveys. However, when the study area is large with strong limitations due to particular orography, those geodetic techniques cannot always grant accurate target points optimally distributed within the monitored object, and only an external reference frame is available to provide absolute orientation to those 3D point clouds or models. In that case, terrestrial photogrammetry shows clear advantages compared to terrestrial laser scanning. Still, it may require a large number of high-quality images taken from well-distributed stations, thus hampering the desired fast data collection. A possible alternative to cope with this problem is the use of the panoramic photogrammetry method by using robotic devices like Gigapan along with a systematic collection procedure from stable stations of a reference frame whose coordinates are accurate and well-controlled. This contribution describes an experiment conducted in Cortes de Pallás (Spain), where an existing infrastructure consisting of 10 pillars and 15 check points is annually monitored at millimetric level, to investigate the potential of long-range panoramic photogrammetry as applied to deformation monitoring. The panoramic images were taken from 7 selected pillars using the Gigapan robotic device. The accuracy of oriented panoramic images, the performance of the method in long-ranges (500-1000 m), and the consistency with the geodetic techniques in the 15 check points were analyzed. Finally, some conclusions about the suitability of panoramic photogrammetry as applied to long-range deformation monitoring are drawn.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129516841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13671
S. Durand, M. Lösler, Mark Jones, P. Cattin, S. Guillaume, L. Morel
The dependency of the results from a network adjustment on the application used is investigated. For that purpose, the results obtained by each tested application on several sets of simulated measurements are compared. In each simulation, only one parameter varies. We first present our comparison methodology and the method that was used to add Gaussian-like errors to theoretical measurements. We then apply it to study the impact of the side length of the network and of the ellipsoidal height difference among points in the network for several network adjustment applications: Columbus, CoMeT, Geolab, JAG3D, LGC, Move3, Star*Net and Trinet+.
{"title":"Quantification of the dependence of the results on several network adjustment applications","authors":"S. Durand, M. Lösler, Mark Jones, P. Cattin, S. Guillaume, L. Morel","doi":"10.4995/jisdm2022.2022.13671","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13671","url":null,"abstract":"The dependency of the results from a network adjustment on the application used is investigated. For that purpose, the results obtained by each tested application on several sets of simulated measurements are compared. In each simulation, only one parameter varies. We first present our comparison methodology and the method that was used to add Gaussian-like errors to theoretical measurements. We then apply it to study the impact of the side length of the network and of the ellipsoidal height difference among points in the network for several network adjustment applications: Columbus, CoMeT, Geolab, JAG3D, LGC, Move3, Star*Net and Trinet+.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134377421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13830
L. Balangé, C. Harmening, Rebeca Duque Estrada, A. Menges, H. Neuner, V. Schwieger
The Cluster of Excellence Integrative Computational Design and Construction for Architecture at the University of Stuttgart brings together various disciplines to jointly develop amongst other things a better understanding of processes in the manufacturing and construction domain. One of the cluster’s aims is to create new solutions for the construction of lightweight fibrous structures using coreless winding of lightweight fiber composite systems. For this purpose, a precise geometry and an understanding of the fibers’ behavior during the production process are of major importance. The fibers’ production process is monitored by repeatedly scanning the fibers during different stages of the process using a terrestrial laser scanner. In order to determine the geometry of the fibers’ axes as well as their cross-sections, two different strategies are used. The first strategy focuses on the segmentation of several straight lines between two intersection points. For the comparison of the individual fabrication steps, the positions of the intersection points are contrasted. For the cross-sectional areas of the fibers, orthogonal planes of intersection are then defined and all points within a predefined area are projected onto this plane. Then the area is calculated using a convex hull. In the second strategy, the fibers‘ main axes are represented by best-fitting B-spline curves. The borders of the cross-sections of interest are also approximated by best-fitting B-spline curves, forming the basis for the final determination of the cross-sectional areas. In this case study two epochs are analyzed with a deformation of the size of around 1cm. For both epochs the cross-sections are calculated in cm steps.
{"title":"Monitoring the production process of lightweight fibrous structures using terrestrial laser scanning","authors":"L. Balangé, C. Harmening, Rebeca Duque Estrada, A. Menges, H. Neuner, V. Schwieger","doi":"10.4995/jisdm2022.2022.13830","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13830","url":null,"abstract":"The Cluster of Excellence Integrative Computational Design and Construction for Architecture at the University of Stuttgart brings together various disciplines to jointly develop amongst other things a better understanding of processes in the manufacturing and construction domain. One of the cluster’s aims is to create new solutions for the construction of lightweight fibrous structures using coreless winding of lightweight fiber composite systems. For this purpose, a precise geometry and an understanding of the fibers’ behavior during the production process are of major importance. The fibers’ production process is monitored by repeatedly scanning the fibers during different stages of the process using a terrestrial laser scanner. In order to determine the geometry of the fibers’ axes as well as their cross-sections, two different strategies are used. The first strategy focuses on the segmentation of several straight lines between two intersection points. For the comparison of the individual fabrication steps, the positions of the intersection points are contrasted. For the cross-sectional areas of the fibers, orthogonal planes of intersection are then defined and all points within a predefined area are projected onto this plane. Then the area is calculated using a convex hull. In the second strategy, the fibers‘ main axes are represented by best-fitting B-spline curves. The borders of the cross-sections of interest are also approximated by best-fitting B-spline curves, forming the basis for the final determination of the cross-sectional areas. In this case study two epochs are analyzed with a deformation of the size of around 1cm. For both epochs the cross-sections are calculated in cm steps.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131903335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13691
U. Kallio, Joona Eskelinen, J. Jokela, H. Koivula, Simo Marila, J. Näränen, M. Poutanen, A. Raja-Halli, Paavo Rouhiainen, Heli Suurmäki
VLBI telescope reference point, the closest point in the telescope primary axis from the secondary axis, is typically determined indirectly by observation of points co-rotating with the telescope. We have previously measured telescope reference point indirectly with two GPS-antennas attached on the edge of the dish of the Aalto University Metsähovi radio telescope in 2008-2015. Now we have applied the same technique to the new VGOS-telescope of the FGI Metsähovi geodetic research station. The reference point of the VGOS antenna was estimated using post-processed trajectory coordinates of two GNSS antennas. The antennas are attached on the edge of the radio telescope dish with gimbals where a counterweight with shock absorber act as compensators to ensure zenith pointing at all telescope elevation angles. In addition, spherical prisms are attached to the structure of the telescope for tachymetric reference point determination. One purpose of this study is to evaluate the limit values and uncertainties of the compensator assembly by simulations and precise tachymeter measurements. To ensure that the compensation error is nearly constant or can be modelled, we have measured the residual tilt of the GNSS antennas with different VLBI antenna elevations. The results indicate a need to apply the corrections or to improve the compensator design. We aim to improve the counterweight and dampening so that no extra model corrections to trajectory coordinates are needed. For final assurance of our GNSS-based reference point monitoring performance, we have compared the reference point coordinates determined by simultaneous tachymetric and GNSS data. Our results and simulations showed that, with a small compensation error, the influence on reference point coordinates is marginal but the axis offset will be compromised, provided that the compensating angle bias is nearly constant. Preliminary reference point estimates show a rather good agreement of simultaneous GNSS-based and tachymetric reference points. The final results will be achieved as part of the 18SIB01 EMPIR GeoMetre project, funded from the EMPIR programme and co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.
{"title":"Validation of GNSS-based reference point monitoring of the VGOS VLBI telescope at Metsähovi","authors":"U. Kallio, Joona Eskelinen, J. Jokela, H. Koivula, Simo Marila, J. Näränen, M. Poutanen, A. Raja-Halli, Paavo Rouhiainen, Heli Suurmäki","doi":"10.4995/jisdm2022.2022.13691","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13691","url":null,"abstract":"VLBI telescope reference point, the closest point in the telescope primary axis from the secondary axis, is typically determined indirectly by observation of points co-rotating with the telescope. We have previously measured telescope reference point indirectly with two GPS-antennas attached on the edge of the dish of the Aalto University Metsähovi radio telescope in 2008-2015. Now we have applied the same technique to the new VGOS-telescope of the FGI Metsähovi geodetic research station. The reference point of the VGOS antenna was estimated using post-processed trajectory coordinates of two GNSS antennas. The antennas are attached on the edge of the radio telescope dish with gimbals where a counterweight with shock absorber act as compensators to ensure zenith pointing at all telescope elevation angles. In addition, spherical prisms are attached to the structure of the telescope for tachymetric reference point determination. One purpose of this study is to evaluate the limit values and uncertainties of the compensator assembly by simulations and precise tachymeter measurements. To ensure that the compensation error is nearly constant or can be modelled, we have measured the residual tilt of the GNSS antennas with different VLBI antenna elevations. The results indicate a need to apply the corrections or to improve the compensator design. We aim to improve the counterweight and dampening so that no extra model corrections to trajectory coordinates are needed. For final assurance of our GNSS-based reference point monitoring performance, we have compared the reference point coordinates determined by simultaneous tachymetric and GNSS data. Our results and simulations showed that, with a small compensation error, the influence on reference point coordinates is marginal but the axis offset will be compromised, provided that the compensating angle bias is nearly constant. Preliminary reference point estimates show a rather good agreement of simultaneous GNSS-based and tachymetric reference points. The final results will be achieved as part of the 18SIB01 EMPIR GeoMetre project, funded from the EMPIR programme and co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"2394 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130578689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.4995/jisdm2022.2022.13728
Felix Esser, José Angel Moraga, L. Klingbeil, H. Kuhlmann
The detection of deformations on man-made structures such as bridges and dams are an essential task in engineering geodesy. The classical method uncovering deformations is based on geodetic networks using measurements from total stations or GNSS receivers. Another new approach is the determination of deformations based on terrestrial laser scans leading to large-scale deformation results by point cloud comparisons. In the field of geodetic engineering, mobile laser scanning systems are increasingly used for high-resolution point cloud generation in short measurement times, which leads to the idea to use these for deformation analysis. A crucial part of this measurement strategy is the estimation of the trajectory (position and orientation) of the scanner, which allows a consistent registration of the single scan lines in a global coordinate system (georeferencing). The largest limitation to the accuracy of the resulting point cloud is the accuracy of the estimated trajectory. In most applications, the estimation of position and orientation are based on the fusion of GNSS (Global Navigation Satellite System) and IMU (Inertial Measurement Unit) measurements. Systematic errors, as they often appear in GNSS measurements, are directly transferred to the georeferenced point cloud and therefor limit the potential for deformation analysis. With this paper we address the questions, if the trajectory estimation can be improved by the integration of known landmarks into the trajectory estimation procedure. Using a point cloud generated with an initial GNSS/IMU based trajectory, landmark targets can be observed in the point cloud and integrated into an updated estimate, using a factor graph-based approach. For the evaluation of a potential accuracy increase due to landmark observations, we performed measurements, comparing GNSS/IMU based results with the ones where landmarks are additionally integrated. The experiments show, that the accuracy increases especially in the heading angle, which is reflected in lower residuals to observed reference coordinates, but also in the trajectory covariances of the estimation results.
{"title":"Accuracy improvement of mobile laser scanning point clouds using graph-based trajectory optimization","authors":"Felix Esser, José Angel Moraga, L. Klingbeil, H. Kuhlmann","doi":"10.4995/jisdm2022.2022.13728","DOIUrl":"https://doi.org/10.4995/jisdm2022.2022.13728","url":null,"abstract":"The detection of deformations on man-made structures such as bridges and dams are an essential task in engineering geodesy. The classical method uncovering deformations is based on geodetic networks using measurements from total stations or GNSS receivers. Another new approach is the determination of deformations based on terrestrial laser scans leading to large-scale deformation results by point cloud comparisons. In the field of geodetic engineering, mobile laser scanning systems are increasingly used for high-resolution point cloud generation in short measurement times, which leads to the idea to use these for deformation analysis. A crucial part of this measurement strategy is the estimation of the trajectory (position and orientation) of the scanner, which allows a consistent registration of the single scan lines in a global coordinate system (georeferencing). The largest limitation to the accuracy of the resulting point cloud is the accuracy of the estimated trajectory. In most applications, the estimation of position and orientation are based on the fusion of GNSS (Global Navigation Satellite System) and IMU (Inertial Measurement Unit) measurements. Systematic errors, as they often appear in GNSS measurements, are directly transferred to the georeferenced point cloud and therefor limit the potential for deformation analysis. With this paper we address the questions, if the trajectory estimation can be improved by the integration of known landmarks into the trajectory estimation procedure. Using a point cloud generated with an initial GNSS/IMU based trajectory, landmark targets can be observed in the point cloud and integrated into an updated estimate, using a factor graph-based approach. For the evaluation of a potential accuracy increase due to landmark observations, we performed measurements, comparing GNSS/IMU based results with the ones where landmarks are additionally integrated. The experiments show, that the accuracy increases especially in the heading angle, which is reflected in lower residuals to observed reference coordinates, but also in the trajectory covariances of the estimation results.","PeriodicalId":404487,"journal":{"name":"Proceedings of the 5th Joint International Symposium on Deformation Monitoring - JISDM 2022","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125707195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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