@inproceedings{MeyerBrunn, author = {Meyer, Theresa and Brunn, Ansgar}, title = {3D Point Clouds in PostgreSQL/PostGIS for Applications in GIS and Geodesy}, series = {Proceedings of the 5th International Conference on Geographical Information Systems Theory, Applications and Management}, booktitle = {Proceedings of the 5th International Conference on Geographical Information Systems Theory, Applications and Management}, publisher = {SCITEPRESS - Science and Technology Publications}, isbn = {978-989-758-371-1}, doi = {10.5220/0007840901540163}, pages = {154 -- 163}, abstract = {Besides the common approach of an exclusively file based management of 3D point clouds, meanwhile it is possible to store and process this special type of massive geodata within spatial database systems. Users benefit from the general advantages of database solutions and especially from the potentials of a combined analysis of original 3D point clouds, 2D rasters, 3D voxel stacks and 2D and 3D vector data in order to gain valuable geo- information. This paper describes the integration of 3D point clouds into an open source PostgreSQL/PostGIS database using the Pointcloud extension and functions of the Point Data Abstraction Library (PDAL). The focus is on performing three-dimensional spatial queries and the evaluation of different tiling methods for the organization of 3D point clouds into table rows, regarding memory space, performance of spatial queries and effects on interactions between point clouds and other GIS features within the database. A new approach for an optimized point cloud tiling, considering the individual geometric characteristic of a 3D point cloud, is presented. The results show that an individually selected storage structure for a point cloud is crucial for low memory consumption and high-performance 3D queries in PostGIS applications, taking account of its three-dimensional spatial extent and point density.}, language = {en} } @inproceedings{MeyerBrunnStilla, author = {Meyer, Theresa and Brunn, Ansgar and Stilla, Uwe}, title = {Genauigkeitsbetrachtung voxelbasierter {\"A}nderungsdetektion im Geb{\"a}udeinnenbereich zur automatisierten Baufortschritts{\"u}berwachung}, series = {Publikationen der Deutschen Gesellschaft f{\"u}r Photogrammetrie, Fernerkundung und Geoinformation e.V.}, volume = {30}, booktitle = {Publikationen der Deutschen Gesellschaft f{\"u}r Photogrammetrie, Fernerkundung und Geoinformation e.V.}, doi = {10.24407/KXP:1796028584}, abstract = {Dieser Beitrag handelt von einer Methode zur {\"A}nderungsdetektion im Geb{\"a}udeinneren, die auf der Diskretisierung des Objektraums durch Voxel basiert. Die Belegung des Voxelraums wird anhand von Punktwolken aus terrestrischem Laserscanning zu verschiedenen Bauphasen ermittelt. Durch die Aufdeckung von Belegungskonflikten zwischen zwei Messepochen wird ermittelt, ob {\"A}nderungen an einer bestimmten Stelle aufgetreten sind. Es wird gezeigt, wie sich der Diskretisierungsfehler als Resultat der Voxelisierung auf die noch erreichbare r{\"a}umliche Aufl{\"o}sung einer {\"A}nderungsaussage auswirkt. Am Beispiel von Abbrucharbeiten bei einem Innenumbauprojekt werden die wechselseitigen Auswirkungen von Aufnahmegeometrie, Scanaufl{\"o}sung und Voxelgr{\"o}ße diskutiert. Die Ergebnisse zeigen, dass die Aufl{\"o}sung von 3D-Punktwolken unter Beachtung einiger Anforderungen an die Aufnahmegeometrie bei Innenraum-Messungen ausreicht, um bei g{\"a}ngigen Genauigkeitsanforderungen auf Voxelebene automatisiert strukturelle {\"A}nderungen zu beschreiben.}, language = {de} } @inproceedings{MeyerBrunn, author = {Meyer, Theresa and Brunn, Ansgar}, title = {3D-Punktwolken-Management mit PostgreSQL/PostGIS f{\"u}r praktische Anwendungen in Geoinformationssystemen}, series = {Dreil{\"a}ndertagung der DGPF, der OVG und der SGPF in Wien, {\"O}sterreich - Publikationen der DGPF}, booktitle = {Dreil{\"a}ndertagung der DGPF, der OVG und der SGPF in Wien, {\"O}sterreich - Publikationen der DGPF}, number = {28}, abstract = {Neben dem dateibasierten Management von 3D-Punktwolken besteht seit einigen Jahren auch die M{\"o}glichkeit, diese gemeinsam mit anderen Geodaten in r{\"a}umlichen Datenbanksystemen vorzuhalten und dabei von den Vorteilen der kombinierten Analyse von georeferenzierten Punktwolken-, Raster- und Vektordaten zu profitieren. In diesem Beitrag wird vorgestellt, wie die Punktwolkenerweiterung „Pointcloud" f{\"u}r die PosgreSQL/PostGIS Datenbank mit ihren speziellen Methoden und der Integration von PostGIS-Funktionen genutzt werden kann, um auch r{\"a}umliche Abfragen in 3D zu realisieren. Im Besonderen werden erweiterte M{\"o}glichkeiten zur Punktwolkenkachelung durch Kombinationen von Funktionen der Point Data Abstraction Library (PDAL) aufgezeigt und dahingehend untersucht, in wie weit sich unterschiedliche Kachelmethoden und -konfigurationen auf Speicherplatzbedarf, Abfrageperformance und Interaktionen zwischen Punktwolken und anderen 2D und 3D Geoobjekten in der Datenbank auswirken. Die Ergebnisse zeigen, dass eine individuell gew{\"a}hlte Speicherstruktur f{\"u}r eine Punktwolke unter Ber{\"u}cksichtigung ihrer dreidimensionalen r{\"a}umlichen Ausdehnung und Punktdichte ausschlaggebend f{\"u}r einen geringen Speicherverbrauch und performante Abfragen in PostGIS-Anwendungen ist.}, language = {de} } @article{MeyerBrunnStilla, author = {Meyer, Theresa and Brunn, Ansgar and Stilla, Uwe}, title = {Change detection for indoor construction progress monitoring based on BIM, point clouds and uncertainties}, series = {Automation in Construction}, volume = {141}, journal = {Automation in Construction}, issn = {0926-5805}, doi = {doi.org/10.1016/j.autcon.2022.104442}, abstract = {Automatic construction progress documentation and metric evaluation of execution work in confined building interiors requires particularly reliable geometric evaluation and interpretation of statistically uncertain as-built point clouds. This paper presents a method for high-resolution change detection based on dense 3D point clouds from terrestrial laser scanning (TLS) and the discretization of space by voxels. In order to evaluate the metric accuracy of a BIM according to the Level of Accuracy (LOA) specification, the effects of laser range measurements on the occupancy of space are modeled with belief functions and evaluated using Dempster and Shafer's theory of evidence. The application is demonstrated on the point cloud data of multi temporal scanning campaigns of real indoor reconstructions. The results show that TLS point clouds are suitable to verify a given BIM up to LOA 40 if special attention is paid to the scanning geometry during the acquisition. The proposed method can be used to document construction progress, verify and even update the LOA status of a given BIM, confirming valid and BIM-compliant as-built models for further planning.}, language = {en} } @article{MeyerBrunnStilla, author = {Meyer, Theresa and Brunn, Ansgar and Stilla, Uwe}, title = {Geometric BIM verification of indoor construction sites by photogrammetric point clouds and evidence theory}, series = {ISPRS Journal of Photogrammetry and Remote Sensing}, volume = {195}, journal = {ISPRS Journal of Photogrammetry and Remote Sensing}, pages = {432 -- 445}, abstract = {Photogrammetric point clouds offer immense potential for various applications, especially for the AEC industry and "as-built" BIM. However, despite many advantages such as time and cost efficiency, image based point clouds of indoor environments mostly suffer from inhomogeneous and strongly fluctuating point-wise uncertainties. This lack of area-filling geometric reliability represents a strong barrier for innovations and further development of image based applications for as-built BIM, regarding both software and hardware. Therefore, this paper presents a method for the geometric verification of indoor BIMs by images and uncertainty management in order to unleash the potential of photogrammetry in context of professional building documentation heading towards "digital twinning". Individual 3D point accuracies, object's surface characteristics and BIM related uncertainties according to the Level of Accuracy (LOA) specification are assessed and taken into account. The final decision of whether or not a photogrammetric point cloud confirms a given model within its associated level of accuracy results from a combined reasoning pipeline based on Dempster-Shafer evidence theory. The novel Pho-to-BIM verification method is demonstrated on three real indoor construction sites, each 3D mapped with different image sensors. Based on the experiments it is shown how to set up belief functions for evidence based reasoning individually, depending on the measurement and site characteristics.}, language = {en} } @inproceedings{MeyerBrunn, author = {Meyer, Theresa and Brunn, Ansgar}, title = {Digitale Photogrammetrie und Bildverarbeitung f{\"u}r kleine und mittlere Unternehmen durch "Blended Learning"}, series = {Dreil{\"a}nder-Tagung 2016, Bern}, booktitle = {Dreil{\"a}nder-Tagung 2016, Bern}, abstract = {Um Unternehmen bei der Integration aktuell stark im Fokus stehender, ber{\"u}hrungsloser Messverfahren zu unterst{\"u}tzen, wird in einem Projekt der Hochschule f{\"u}r angewandte Wissenschaften W{\"u}rzburg-Schweinfurt (FHWS), das hybride Bildungskonzept „Blended Learning" verfolgt. Ziel ist es, den Teilnehmern grundlegende Fachkenntnisse in digitaler Photogrammetrie und Bildverarbeitung zu vermitteln. Die Lehr- und Lernstrategien beruhen dabei auf einer Kombination von multimedialen online Lerneinheiten und „klassischen" Pr{\"a}senzveranstaltungen, weshalb sie sich besonders f{\"u}r eine Zielgruppe im t{\"a}glichen Arbeitsleben eignen. Eine stetig wachsende Projektteilnehmerzahl und deren stets große Beteiligung an den Aktivit{\"a}ten im Projekt, zeigen bisher eine positive Resonanz auf das spezielle Informationsangebot.}, language = {de} } @article{BrunnMeyer, author = {Brunn, Ansgar and Meyer, Theresa}, title = {Calibration of a Multi-Camera Rover}, series = {The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences}, journal = {The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences}, doi = {10.5194/isprs-archives-XLI-B5-445-2016}, pages = {445 -- 452}, abstract = {Multi-Camera-Rover are recently coming up for usual terrestrical surveying tasks. This technique is new for the surveyors. Although photogrammetric specialists realize the benefits of such systems immediately, surveyors have difficulties to find efficient usages. To approach this new measurement systems the technique has to be understood and the confidence on the accuray has to grow. In this paper we analyze the accuracy of a Multi-Camera-Rover using an indoor testfield by photogrammetric algorithms. The results show that the knowledge of the interior orientation parameter of the cameras and the relative orientation of the cameras is essential for precise geometric reconstructions. Knowing these additional data, high accurate results become possible.}, language = {en} } @article{MeyerBrunnStilla, author = {Meyer, Theresa and Brunn, Ansgar and Stilla, Uwe}, title = {Accuracy investigation on image-based change detection for BIM compliant indoor models}, series = {ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences}, volume = {4}, journal = {ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences}, pages = {105 -- 112}, language = {en} }