Daniel Wujanz

Daniel Wujanz
technet GmbH Berlin

13.75
 · 
Dr.-Ing.
About
66
Research items
10,688
Reads
204
Citations
Introduction
Daniel Wujanz works at technet, a company that is specialized in Parameter Estimation within large and heterogeneous datasets. Daniel does research in terrestrial laser scanning with a focus on deformation monitoring. That includes the issue of registration, construction site progress monitoring and modelling the stochastic characteristics of laser scanners.
Research Experience
Feb 2010
Technische Universität Berlin
Position
  • Research Assistant & group leader 3D-data acquisition
Feb 2009 - Jan 2010
Jan 2007 - Oct 2008
Network
Cited By
Followers
Following
Projects
Projects (7)
Project
The aim of this project is a) to automatically detect changes on construction sites that occurred over time and b) to automatically derive BIM-compatible construction components from terrestrial laser scans. The basic concept of both algorithms is based on detected planes which allow to increase the error budget of TLS. An extended error budget considers various influences and hence allows to draw sound conclusions.
Project
The main goal of the Joint Summer School 2019 is to provide participants with innovative practical and methodological skills to characterize complex terrain and object features using close- and near range remote sensing techniques. The Summer School will be the third edition after two successful implementations in 2015 and 2017.
Research
Research items (66)
Article
Full-text available
Current research questions in the field of geomorphology focus on the impact of climate change on several processes subsequently causing natural hazards. Geodetic deformation measurements are a suitable tool to document such geomorphic mechanisms, e.g. by capturing a region of interest with terrestrial laser scanners which results in a so-called 3-...
Article
Up until now no appropriate models have been proposed that are capable to describe the stochastic characteristics of reflectorless rangefinders - the key component of terrestrial laser scanners. This state has to be rated as unsatisfactory especially from the perception of Geodesy where comprehensive knowledge about the precision of measurements is...
Preprint
Recent advances in stochastic modelling of reflectorless rangefinders revealed an inherent relationship among raw intensity values and the corresponding precision of observed distances. In order to derive the stochastic properties of a terrestrial laser scanner’s (TLS) rangefinder, distances have to be observed repeatedly. For this, the TLS of inte...
Article
A current aim of ongoing research in the field of deformation measurement is to automatically determine geometric changes between several epochs with data captured by terrestrial laser scanners. A critical component within the process chain of deformation measurement is the transformation of captured point clouds into a reference coordinate system....
Conference Paper
Full-text available
Despite the enormous popularity of terrestrial laser scanners in the field of Geodesy, economic aspects in the context of data acquisition are mostly considered intuitively. In contrast to established acquisition techniques, such as tacheometry and photogrammetry, optimisation of the acquisition configuration cannot be conducted based on assumed ob...
Conference Paper
Full-text available
This contribution deals with the detection of load-induced arch displacements on a bridge by means of 3D point clouds acquired by terrestrial laser scanning (TLS). TLS has proved to be a suitable technique for geodetic monitoring of structures such as bridges as it allows determining object changes with high precision in the low millimeter level at...
Article
Full-text available
Das terrestrische Laserscanning (TLS) kann als etablierte Methode für die quasi-flächenhafte Messung von Deformationen angesehen werden. Basierend auf mindestens zwei gemessenen Epochen gilt es zunächst alle Datensätze in ein gemeinsames Koordinatensystem zu überführen. Anschließend kann eine Deformationsberechnung erfolgen, die numerische Abweichu...
Conference Paper
Full-text available
Bei der Bestandsaufnahme von Gebäuden oder zur Baufortschrittsdokumentation bieten Terrestrische Laserscanner (TLS) einige Vorteile. Zum einen hat man keinen hohen Personalbedarf im Außendienst und man erhält immer eine umfangreiche Erfassung der Situation vor Ort zum Aufnahmezeitpunkt. Der Nachteil ist die Menge an anfallenden Daten, die den per-s...
Presentation
Full-text available
This presentation shows a new algorithm of a plane-based construction site monitoring algorithm. An English article is currently in the making.
Conference Paper
Full-text available
Ein allgegenwärtiges Problem bei der Umsetzung von Bauvorhaben sind zum einen Über-schreitungen der während der Planungsphase geschätzten Bauzeit sowie erhebliche Kosten-steigerungen gegenüber dem veranschlagten Budget. Ein wesentlicher Grund hierfür ist die zumeist mangelhafte Überwachung des Baufortschritts-zum einen im Sinne der Erbringung einer...
Article
Full-text available
A critical task in every terrestrial laser scanning project is the transformation (addressed to as registration or alignment) of multiple point clouds into a common reference system. Even though this operation appears to be a solved and well-understood problem, the vast majority of available techniques still lack meaningful quality measures that al...
Article
Terrestrial laser scanning (TLS) can be regarded as an established method for the quasi-laminar measurement of deformations. Based on at least two measured epochs, all data sets must first be transformed into a common coordinate system. Subsequently, deformation measurement can be performed, which displays numerical deviations from the subsequent t...
Article
Full-text available
Recent advances in stochastic modelling of reflectorless rangefinders revealed an inherent relationship among raw intensity values and the corresponding precision of observed distances. In order to derive the stochastic properties of a terrestrial laser scanner's (TLS) rangefinder, distances have to be observed repeatedly. For this, the TLS of inte...
Article
Full-text available
Recent advances in stochastic modelling of reflectorless rangefinders revealed an inherent relationship among raw intensity values and the corresponding precision of observed distances. In order to derive the stochastic properties of a terrestrial laser scanner’s (TLS) rangefinder, distances have to be observed repeatedly. For this, the TLS of inte...
Answer
Dear Wenpeng,
I suggest that you have a look at HELIOS:
All the best
Daniel
Answer
Dear Sahar,
we have developed an event-based procedure for temporal calibration between a TLS and several total stations (for kinematic laser scanning) and in a second try we reapplied the approach to synchronise a TLS and pair of cameras. If that is of interest for you please let me know.
All the best from Berlin
Daniel
Presentation
Full-text available
Registration of a large set of terrestrial laser scans using a plane-based approach.
Article
Full-text available
The automatic registration of terrestrial laser scans appears to be a solved problem in science as well as in practice. However, this assumption is questionable especially in the context of large projects where an object of interest is described by several thousand scans. A critical issue inherently linked to this task is memory management especial...
Article
Full-text available
The 2nd international summer school “Close-range sensing techniques in Alpine terrain” was held in July 2017 in Obergurgl, Austria. Participants were trained in selected close-range sensing methods, such as photogrammetry, laser scanning and thermography. The program included keynotes, lectures and hands-on assignments combining field project plann...
Article
Full-text available
LiDAR is a consolidated technology for topographic mapping and 3D reconstruction, which is implemented in several platforms On the other hand, the exploitation of the geometric information has been coupled by the use of laser intensity, which may provide additional data for multiple purposes. This option has been emphasized by the availability of s...
Article
Full-text available
Current research questions in the field of geomorphology focus on the impact of climate change on several processes subsequently causing natural hazards. Geodetic deformation measurements are a suitable tool to document such geomorphic mechanisms, e.g. by capturing a region of interest with terrestrial laser scanners which results in a so-called 3-...
Chapter
Full-text available
Zusammenfassung Dieser Beitrag fokussiert auf die Überwachung einer historischen Brücke mittels terrestrischem Laserscanning während eines Belastungsversuchs. Dabei wurde ein Belastungsregime von etwa 1 bis 6 MN durchfahren. Zur Erfassung der statischen Haltephasen wurden 3-D-Laserscanner eingesetzt, welche die Verformung der Brücke infolge des Las...
Chapter
Full-text available
Aus aktueller Sicht werden Methoden zur zerstörungsfreien Prüfung von Brückenbauwerken in der Zukunft eine wichtige Rolle spielen, um den Zustand der etlichen in die Jahre gekommenen Bauwerke zu beurteilen. Forschungsschwerpunkte in der Ingenieurgeodäsie und anderen Disziplinen sind hierbei flächenhafte Verfahren zur Erfassung und Analyse von Defor...
Conference Paper
Full-text available
In diesem Beitrag wird ein neues Verfahren zur gemeinsamen Segmentierung und Registrierung von Punktwolken vorgestellt, das die vorhandene Topologie von Einzel- scans zur Segmentierung nutzt und die daraus extrahierten Merkmale in Form von Ebenen als korrespondierende Informationen für eine Registrierung verwendet, wo- durch die Segmentierung ergän...
Conference Paper
Full-text available
Das terrestrische Laserscanning (TLS) kann als etablierte Methode für die quasi-flächenhafte Messung von Deformationen angesehen werden. Basierend auf mindestens zwei gemessenen Epochen gilt es zunächst alle Datensätze in ein gemeinsames Koordinatensystem zu überführen. Anschließend kann eine Deformationsberechnung erfolgen, die numerische Abweichu...
Conference Paper
Full-text available
Aktuelle Forschungsergebnisse zeigen für terrestrische Laserscanner (TLS) mit Strecken-messung nach dem Phasenvergleichsverfahren einen inhärenten Zusammenhang zwischen Signalstärke und Messrauschen. Diese Tatsache eignet sich somit zur Aufstellung von intensitätsbasierten stochastischen Modellen für TLS. Stochastische Modelle haben eine zentrale B...
Conference Paper
Full-text available
Dieser Beitrag thematisiert die Nutzung von 3D-Punktwolken zum Monitoring von Infrastrukturbauwerken am Beispiel einer historischen Gewölbebrücke bei Verden (Aller). Zur Erfassung von 3D-Punktwolken kommen in diesem Projekt terrestrische Laserscanner zum Einsatz, die sich seit mehr als einer Dekade als effizientes Messsystem zur schnellen Erfassung...
Presentation
Full-text available
The presentation shows first results generated by an algorithm that automatically identifies modifications on construction sites based on multi-temporal laser scans.
Conference Paper
Full-text available
Zusammenfassung: Bis zum heutigen Tage liegen keine aussagekräftigen Modelle vor, die das stochastische Verhalten von reflektorlos-arbeitenden Entfernungsmessern zutreffend beschreiben. Da diese jedoch die Schlüsselkomponente von terrestrischen Laserscannern (TLS) sind, ergibt sich die dringende Notwendigkeit, dieser Forschungsfrage nachzugehen. Di...
Conference Paper
Full-text available
Zusammenfassung Aktuelle Forschungsfragen in der Glaziologie befassen sich mit den Auswirkungen des Klimawandels, die sich unter anderem durch den Rückzug von Gletschern zeigen und in Folge dessen Naturgefahren begünstigen. Um derartige Mechanismen besser verstehen zu können, eignet sich die geodätische Deformationsmessung, insbesondere unter Verwe...
Conference Paper
Full-text available
In diesem Beitrag wird ein neues Verfahren zur Segmentierung von Punktwolken vorgestellt, das sich die durch die regelmäßige Abtastung eines terrestrischen Laserscanners resultierende Rasterdatenstruktur für die Ableitung von geometrischen und radiometrischen Eigenschaften zu Nutze macht. Der Segmentierungsalgorithmus ist durch die Anwendung effizi...
Conference Paper
Full-text available
Trotz der enormen Popularität von terrestrischen Laserscannern findet die Standpunktwahl bisher zumeist intuitiv statt. In diesem Beitrag wird gezeigt, wie eine Standpunktwahl beim terrestrischen Laserscanning unter ökonomischen Gesichtspunkten und im Kontext der Ingenieurgeodäsie erfolgen kann. Die dazu erforderliche Simulation von TLS-Beobachtung...
Article
Full-text available
Terrestrial laser scanning today is frequently applied in practice for areal determination of structural deformations. However, approaches to rigorous deformation analysis and tests of significance are rare. Here we present the reasons and possible strategies to improve the situation. At first we examine the conditions where and when areal deformat...
Answer
Dear Lorcan,
you should check if you're looking at the originally observed intensity values. A lot of manufacturers perform some sort of normalisation or stretching in oder to enhance the visual appearance of the intensity image. Thus, you may not find what you're looking for. Two manufacturers definitely allow to export raw intensity values: Zoller + Fröhlich and Riegl.
cheers
Daniel Wujanz
Presentation
Full-text available
Slides based on the following article: Model based viewpoint planning for terrestrial laser scanning from an economic perspective
Conference Paper
Full-text available
Early career researchers such as PhD students are a main driving force of scientific research and are for a large part responsible for research innovation. They work on specialized topics within focused research groups that have a limited number of members, but might also have limited capacity in terms of lab equipment. This poses a serious challen...
Article
Full-text available
Early career researchers such as PhD students are a main driving force of scientific research and are for a large part responsible for research innovation. They work on specialized topics within focused research groups that have a limited number of members, but might also have limited capacity in terms of lab equipment. This poses a serious challen...
Article
Full-text available
Abstract: Despite the enormous popularity of terrestrial laser scanners in the field of Geodesy and related sciences the vital task of viewpoint planning is mostly considered intuitively. In contrast to established acquisition techniques, such as tacheometry and classical photogrammetry, optimisation of the acquisition configuration cannot be condu...
Conference Paper
Full-text available
Jeder ingenieurgeodätischen Messkampagne geht in der Regel eine ausführliche Standpunktplanung voraus, die einerseits Aspekte der Wirtschaftlichkeit berücksichtigt und anderseits versucht, geforderte Genauigkeitskriterien zu erfüllen. Obwohl terrestrische Laserscanner (TLS)1 mittlerweile etablierte geodätische Instrumente sind, wurden die beiden zu...
Thesis
Full-text available
The determination of geometric changes within an area or object of interest by means of repetitive surveys at different points in time is referred to as geodetic deformation monitoring. Despite its development in the early years of the twentieth century the original processing chain remained identical in essence until now. It contains the choice of...
Conference Paper
Full-text available
Trotz der enormen Popularität von terrestrischen Laserscannern in den meisten Anwendungsgebieten der Geodäsie finden ökonomische Belange lediglich durch rein intuitive Überlegungen Berücksichtigung. Anders als bei den etablierten Messverfahren Tachymetrie und Photogrammetrie kann eine Optimierung der Aufnahmekonfiguration nicht auf Grundlage von Ob...
Conference Paper
The paper presents evaluation of the possibility to utilize laser scanning results for determination of water dam concrete construction outer surfaces conditions. In particular changes in porosity and resistance of concrete. Results of experiments, which have been based on scans of downstream faces of Besko (Poland) and Ecker (Germany) concrete dam...
Conference Paper
Full-text available
Beginning in 2000 annual terrestrial laser scanning has been applied at the very active rock glacier Hin-teres Langtalkar annually collecting the longest record of laser scanning in periglacial studies, at least in Europe. Despite the fact that independently measured 3D-movement reach magnitudes of up to 3.40 ma-1, inherent measurement uncertaintie...
Article
Full-text available
Das Ziel aktueller Forschungen zur Deformationsanalyse unter Verwendung terrestrischer Laserscanner (TLS) besteht darin, geometrische Veränderungen zwischen verschiedenen Messepochen automatisch zu erkennen. Als Schlüsselproblematik erweist sich dabei die Verknüpfung einzelner Punktwolken in ein gemeinsames Koordinatensystem, was bisher unter Verwe...
Conference Paper
Full-text available
Deformation analysis based on multi-temporal Terrestrial Laser Scanning (TLS) surveys has been applied for many years in commercial and academic problem domains. Downsides of this technique are the sequential data acquisition as well as its limited accuracy compared to terrestrial InSAR or InRAR based technologies that are currently gaining attenti...
Conference Paper
Full-text available
Terrestrial laser scanning (TLS) can be seen as an established method for geodetic data acquisition. Advantageous is its high achievable accuracy as well as its rapid, active and laminar sampling of the object space. However, problems occur if an object, the scanner itself or both are moving which is referred to as kinematic TLS (k-TLS). The cause...
Article
Full-text available
Das terrestrische Laserscanning (TLS) hat sich als Messverfahren für geodätische Aufgabenstellungen etabliert. Vorteilhaft an dieser Technik sind die hohe erreichbare Genauigkeit sowie die schnelle, aktive und flächenhafte Abtastung des Objektraums. Probleme treten jedoch auf, wenn ein zu erfassendes Objekt oder der Scanner in Bewegung ist, was als...
Article
Full-text available
One aim of this project was the determination of sensor positions on a ship by applying terrestrial laser scanning. Furthermore the outer shell of the vessel has been captured by digital imagery and processed to a 3D point cloud by using multi view stereo software namely Visual SfM and 123Dcatch. Finally the captured interior and exterior point clo...
Conference Paper
Full-text available
Im Zuge einer gemeinsamen Arbeit wurden in einem Steinbruch Verformungsmessungen mit einem terrestrischen Laserscanner und einem terrestrischen Radarscanner durchgeführt. Anhand der Auswerteergebnisse werden die Vorteile und Grenzen der einzelnen Messsysteme aufgezeigt und eine Möglichkeit vorgestellt, die charakteristischen Eigenschaften beider Sy...
Conference Paper
Full-text available
A current aim of ongoing research is to automatically determine geometric changes between several epochs captured by terrestrial laser scanning. A critical component within the process chain of deformation monitoring is the transformation of subsequently captured point clouds into a reference respectively superior coordinate system. This step has u...
Conference Paper
Full-text available
Terrestrial Laser Scanners have been widely accepted as a surveying instrument in research as well as in commercial applications. While aspects of scanner accuracy and other influential impacts onto the measured values have been extensively analysed, the impact of registration methods and especially the assessment of transformation parameters remai...
Conference Paper
Full-text available
The detection of deviations plays a crucial role in quality assurance as well as in manufacturing processes where for instance differences between a CAD and the current state of an object have to be determined. Hence a problem that arises is the interpretation of the outcome which is displayed on a monitor in 2D. By combining a projector and 3D-mea...
Conference Paper
Full-text available
Zusammenfassung Mobiles 3D-Indoor Mapping stellt eine neue Herausforderung insbesondere in den Berei-chen Robotik, Building Information Modelling (BIM) oder etwa der sicherheitstechnischen Überwachung von Gebäuden dar. Besonders die Positionierung und Orientierung der Sen-sorplattform während der dynamischen Messung birgt eine Vielzahl an Problemen...
Article
Full-text available
A calibration method for intensity values from a 3D laser scanner (Leica HDS 3000) is presented in this paper. Different influences on the returning laser beam by objects were inspected by using different measurement setups whereby subsequent established variances were compensated. In order to assess the quality of the determined design models for...