scholarly journals A Quadratic Model with Nonpolynomial Terms for Remote Colorimetric Calibration of 3D Laser Scanner Data Based on Piecewise Cubic Hermite Polynomials

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Alessandro Danielis ◽  
Massimiliano Guarneri ◽  
Massimo Francucci ◽  
Mario Ferri De Collibus ◽  
Giorgio Fornetti ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Hermite Polynomials ◽  
Laser Scanner ◽  
Calibration Method ◽  
Added Value ◽  
Quadratic Model ◽  
Laser Scanners ◽  
Colorimetric Data ◽  
Heritage Area ◽  
Lambertian Model

The processing of intensity data from terrestrial laser scanners has attracted considerable attention in recent years. Accurate calibrated intensity could give added value for laser scanning campaigns, for example, in producing faithful 3D colour models of real targets and classifying easier and more reliable automatic tools. In cultural heritage area, the purely geometric information provided by the vast majority of currently available scanners is not enough for most applications, where indeed accurate colorimetric data is needed. This paper presents a remote calibration method for self-registered RGB colour data provided by a 3D tristimulus laser scanner prototype. Such distinguishing colour information opens new scenarios and problems for remote colorimetry. Using piecewise cubic Hermite polynomials, a quadratic model with nonpolynomial terms for reducing inaccuracies occurring in remote colour measurement is implemented. Colorimetric data recorded by the prototype on certified diffusive targets is processed for generating a remote Lambertian model used for assessing the accuracy of the proposed algorithm. Results concerning laser scanner digitizations of artworks are reported to confirm the effectiveness of the method.

scholarly journals FINE REGISTRATION OF KILO-STATION NETWORKS - A MODERN PROCEDURE FOR TERRESTRIAL LASER SCANNING DATA SETS

2016 ◽  
Vol XLI-B5 ◽  
pp. 485-492
Author(s):  
J.-F. Hullo
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Data Sets ◽  
Data Set ◽  
Information Models ◽  
3D Network ◽  
Laser Scanners ◽  
Building Information ◽  
Set Up ◽  
Fine Registration

We propose a complete methodology for the fine registration and referencing of kilo-station networks of terrestrial laser scanner data currently used for many valuable purposes such as 3D as-built reconstruction of Building Information Models (BIM) or industrial asbuilt mock-ups. This comprehensive target-based process aims to achieve the global tolerance below a few centimetres across a 3D network including more than 1,000 laser stations spread over 10 floors. This procedure is particularly valuable for 3D networks of indoor congested environments. In situ, the use of terrestrial laser scanners, the layout of the targets and the set-up of a topographic control network should comply with the expert methods specific to surveyors. Using parametric and reduced Gauss-Helmert models, the network is expressed as a set of functional constraints with a related stochastic model. During the post-processing phase inspired by geodesy methods, a robust cost function is minimised. At the scale of such a data set, the complexity of the 3D network is beyond comprehension. The surveyor, even an expert, must be supported, in his analysis, by digital and visual indicators. In addition to the standard indicators used for the adjustment methods, including Baarda’s reliability, we introduce spectral analysis tools of graph theory for identifying different types of errors or a lack of robustness of the system as well as <i>in fine</i> documenting the quality of the registration.

scholarly journals The Development of Terrestrial Laser Scanning Technology And Its Applications in Mine Shafts in Poland

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
TOMASZ Lipecki ◽  
Kim THI THU HUONG
Keyword(s):  
Laser Scanning ◽  
Full Range ◽  
Laser Scanner ◽  
Mining Industry ◽  
Terrestrial Laser Scanning ◽  
Mechanical Tests ◽  
Scanning Method ◽  
Laser Scanners ◽  
Data Capturing ◽  
Proper Operation

Laser scanners are used more and more as surveying instruments for various applications. With the advance of high precisions systems, laser scanner devices can work in most real-world environments under many different conditions. In the field of mining surveying open up a new method with data capturing. Mining industry requires precise data in order to be able to have a as-built documentation of the facility. Nowadays, the mines are increasingly deepened. For the safe operation of the underground mine, special attention is paid to vertical transport and a set of devices supporting it, mounted in mining shafts. All components must meet stringent criteria for proper operation. The classic geodetic measurements and mechanical tests are long-lasting and do not always provide the full range of information needed about the condition of the object. This paper reports about terrestrial laser scanning method and system mobile terrestrial laser scanning, which has been applied at many vertical shafts in mines of Poland for determining geometric deformation of vertical shaft elements. This system gives high precision 1-3 mm in every horizontal cross – section. Processing time is very quickly and need only few staff to implement all system.

scholarly journals Reality Capture of Buildings Using 3D Laser Scanners

2021 ◽  
Author(s):  
Avar Almukhtar ◽  
Henry Abanda ◽  
Zaid O. Saeed ◽  
Joseph H.M. Tah
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Construction Project ◽  
Laser Scanner ◽  
Data File ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Laser Scanners ◽  
Project Data

The urgent need to improve performance in the construction industry has led to the adoption of many innovative technologies. 3D laser scanners are amongst the leading technologies being used to capture and process assets or construction project data for use in various applications. Due to its nascent nature, many questions are still unanswered about 3D laser scanning, which in turn contribute to the slow adaptation of the technology. Some of these include the role of 3D laser scanners in capturing and processing raw construction project data. How accurate is the 3D laser scanner or point cloud data? How does laser scanning fit with other wider emerging technologies such as Building Information Modelling (BIM)? This study adopts a proof-of-concept approach, which in addition to answering the afore-mentioned questions, illustrates the application of the technology in practice. The study finds that the quality of the data, commonly referred to as point cloud data is still a major issue as it depends on the distance between the target object and 3D laser scanner’s station. Additionally, the quality of the data is still very dependent on data file sizes and the computational power of the processing machine. Lastly, the connection between laser scanning and BIM approaches is still weak as what can be done with a point cloud data model in a BIM environment is still very limited. The aforementioned findings reinforce existing views on the use of 3D laser scanners in capturing and processing construction project data.

Use of Laser Scanner for Digital Surveying of the Sarnicli Inn and the Byzantine Cistern Underneath

2017 ◽  
pp. 227-254
Author(s):  
Gülhan Benli ◽  
Eylem Görmüş Ekizce
Keyword(s):  
Cultural Heritage ◽  
Protected Areas ◽  
Laser Scanning ◽  
Laser Scanner ◽  
3D Scanning ◽  
Measurement Methods ◽  
Advanced Technology ◽  
Laser Scanners ◽  
Close Range ◽  
Photogrammetric Measurement

Measurement methods including traditional measurement methods, topographic and photogrammetric measurement methods, measurements via laser scanning devices and aerial photogrammetric measurement methods obtained using model airplane or model helicopters are used in documentation of the cultural heritage and protected areas in our country. Although data obtained by Aerial Lidar technology accepted as advanced technology over the past decade, enables faster data comparing to others as data obtained by terrestrial laser scanners provide millimetre level accuracy close-range scanning methods are preferred in architectural facades scanning during the process of surveying of a single building. Inclusion process of a Byzantine cistern in Istanbul, Turkey, which was undiscovered for centuries, in our cultural heritage as well as surveying stages of the cistern along with the inn structure built over, using 3D scanning technology shall be described within this study.

scholarly journals COMPARISON WITH ACCURACY OF TERRESTRIAL LASER SCANNER BY USING POINT CLOUD ALIGNED WITH SHAPE MATCHING AND BEST FITTING METHODS

2019 ◽  
Vol XLII-2/W9 ◽  
pp. 535-541 ◽  
Author(s):  
T. Ogawa ◽  
Y. Hori
Keyword(s):  
Laser Scanning ◽  
Shape Matching ◽  
Laser Scanner ◽  
Point Clouds ◽  
Random Errors ◽  
Laser Scanners ◽  
Error Distributions ◽  
Best Fitting ◽  
Scan Data ◽  
Fitting In

<p><strong>Abstract.</strong> Recently operation systems of laser scanning have been obviously improved; for instance shape matching has been equipped with software on a post processing stage so measurement without any targets is a prerequisite condition of field surveying with laser scanners. Moreover a shape matching method enables us to easily register a pair of point clouds with some errors even if those data are scanned by several type scanners. Those slightly errors can influence accuracy of alignments if the object is large to require a lot of scans. Laser scanning data has random errors and accuracy of alignments can be improved by matching error distributions of pairs of point clouds to natural distributions. This method is called “best fitting” in contrast “shape matching” in a software, PolyWorks |Inspector. In this paper, accuracy of alignments between shape matching and best fitting is discussed. The scan data of three phaseshift laser scanners (FARO Focus 3D MS120, FARO Focus 3D X330 and Z+F Imager 5016) and two time-of-flight scanners (Leica BLK 360 and Leica Scan station C5) are used for analyses. Accuracy of alignments by using shape matching and best fitting methods is demonstrated by showing points of scan data with histograms of error distributions.</p>

scholarly journals FINE REGISTRATION OF KILO-STATION NETWORKS - A MODERN PROCEDURE FOR TERRESTRIAL LASER SCANNING DATA SETS

2016 ◽  
Vol XLI-B5 ◽  
pp. 485-492
Author(s):  
J.-F. Hullo
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Data Sets ◽  
Data Set ◽  
Information Models ◽  
3D Network ◽  
Laser Scanners ◽  
Building Information ◽  
Set Up ◽  
Fine Registration

We propose a complete methodology for the fine registration and referencing of kilo-station networks of terrestrial laser scanner data currently used for many valuable purposes such as 3D as-built reconstruction of Building Information Models (BIM) or industrial asbuilt mock-ups. This comprehensive target-based process aims to achieve the global tolerance below a few centimetres across a 3D network including more than 1,000 laser stations spread over 10 floors. This procedure is particularly valuable for 3D networks of indoor congested environments. In situ, the use of terrestrial laser scanners, the layout of the targets and the set-up of a topographic control network should comply with the expert methods specific to surveyors. Using parametric and reduced Gauss-Helmert models, the network is expressed as a set of functional constraints with a related stochastic model. During the post-processing phase inspired by geodesy methods, a robust cost function is minimised. At the scale of such a data set, the complexity of the 3D network is beyond comprehension. The surveyor, even an expert, must be supported, in his analysis, by digital and visual indicators. In addition to the standard indicators used for the adjustment methods, including Baarda’s reliability, we introduce spectral analysis tools of graph theory for identifying different types of errors or a lack of robustness of the system as well as &lt;i&gt;in fine&lt;/i&gt; documenting the quality of the registration.

scholarly journals Post-mission misalignment angle calibration for airborne laser scanners

2021 ◽  
Author(s):  
Wendy Anne Dillane
Keyword(s):  
Laser Pulse ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Laser Pulses ◽  
Angular Misalignment ◽  
Data Set ◽  
Point Matching ◽  
Airborne Laser ◽  
Laser Scanners ◽  
Least Squares Adjustment

An Airborne Laser Scanning (ALS) system operates by locating returned laser pulses independently from all others. Locating the returned laser pulses requires knowing precisely for each laser pulse, the aircraft position (e.g. GPS), the attitude of the aircraft (e.g. IMU), the scanner angle when the laser pulse left the sensor, and the slant range to the terrain surface for that pulse. One of the most critical errors in ALS systems is the angular misalignment between the scanner and the IMU, which is called the misalignment or boresight error. This error must be addressed before an ALS system can accurately produce data. The purpose of this thesis was to develop and test a method of estimating the small misalignment angles between the laser scanner and the combined GPS/IMU solution for position and attitude. This method is semi-automated, requires no ground control and does not re-sample the ALS data in order to match the overlapping strips of data. A computer program called Misalignment Estimator was developed to estimate the misalignment angles using a least squares adjustment. The method was tested using a data set located at the Oshawa airport and provided by Optech. The misalignment angles were estimated to be -0.0178 degrees, -0.0829 degrees and 0.0320 degrees, for roll, pitch and heading respectively. The estimation of the misalignment angles was considered to be successful. Further research into automated point matching is recommended.

scholarly journals 3D RECONSTRUCTION OF THE <i>ROMAN DOMUS</i> IN THE ARCHAEOLOGICAL SITE OF <i>LYLIBAEUM</i> (MARSALA, ITALY)

2019 ◽  
Vol XLII-2/W15 ◽  
pp. 437-442
Author(s):  
D. Ebolese ◽  
M. Lo Brutto ◽  
G. Dardanelli
Keyword(s):  
3D Reconstruction ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Archaeological Site ◽  
Technological Evolution ◽  
Laser Scanners ◽  
Scan Registration ◽  
High Level ◽  
Data Acquisition Strategy

<p><strong>Abstract.</strong> Generally, terrestrial laser scanning surveys involve a rather large number of scans to ensure a high percentage of overlap required for the scan registration phase (target-based or point-based registration, cloud-to-cloud registration). These approaches result in data redundancy that could slow down both the acquisition and post-processing phases. In recent years, the technological evolution in the field of laser scanners has been directed to the development of devices that are able to perform an onsite pre-registration, to optimize the survey procedures and the reliability of the registration of the scan. The paper presents the results achieved during a terrestrial laser scanning survey carried out for the documentation and 3D reconstruction of the large and complex archaeological remains of the so-called Roman <i>Domus</i> in the archaeological site of <i>Lylibaeum</i> (Marsala, Italy). The survey was also conducted using a terrestrial laser scanner capable of pre-registering scans using a topographic approach. The pre-registration procedure and the data acquisition strategy have allowed to optimize the workflow and to obtain a 3D model of the Roman <i>Domus</i> with a high level of detail and area coverage.</p>

Use of Laser Scanner for Digital Surveying of the Sarnicli Inn and the Byzantine Cistern Underneath

2019 ◽  
pp. 275-303
Author(s):  
Gülhan Benli ◽  
Eylem Görmüş Ekizce
Keyword(s):  
Cultural Heritage ◽  
Protected Areas ◽  
Laser Scanning ◽  
Laser Scanner ◽  
3D Scanning ◽  
Measurement Methods ◽  
Advanced Technology ◽  
Laser Scanners ◽  
Close Range ◽  
Photogrammetric Measurement

Measurement methods including traditional measurement methods, topographic and photogrammetric measurement methods, measurements via laser scanning devices and aerial photogrammetric measurement methods obtained using model airplane or model helicopters are used in documentation of the cultural heritage and protected areas in our country. Although data obtained by Aerial Lidar technology accepted as advanced technology over the past decade, enables faster data comparing to others as data obtained by terrestrial laser scanners provide millimetre level accuracy close-range scanning methods are preferred in architectural facades scanning during the process of surveying of a single building. Inclusion process of a Byzantine cistern in Istanbul, Turkey, which was undiscovered for centuries, in our cultural heritage as well as surveying stages of the cistern along with the inn structure built over, using 3D scanning technology shall be described within this study.

Improved area-based deformation analysis of a radio telescope’s main reflector based on terrestrial laser scanning

2015 ◽  
Vol 9 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Christoph Holst ◽  
Axel Nothnagel ◽  
Martin Blome ◽  
Philip Becker ◽  
Malwin Eichborn ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Focal Length ◽  
Elevation Angle ◽  
Laser Scanner ◽  
Deformation Analysis ◽  
Laser Scanners ◽  
Measurement Concept ◽  
Main Reflector ◽  
Best Fit ◽  
Scanner Calibration

AbstractThe main reflectors of radio telescopes deform due to gravitation when changing their elevation angle. This can be analyzed by scanning the paraboloid surface with a terrestrial laser scanner and by determining focal length variations and local deformations from best-fit approximations.For the Effelsberg radio telescope, both groups of deformations are estimated from seven points clouds measured at different elevation angles of the telescope: the focal length decreases by 22.7 mm when tilting the telescope from 90 deg to 7.5 deg elevation angle. Variable deformations of ± 2 mm are detected as well at certain areas. Furthermore, a few surface panels seem to be misaligned.Apart from these results, the present study highlights the need for an appropriate measurement concept and for preprocessing stepswhen using laser scanners for area-based deformation analyses. Especially, data reduction, object segmentation and laser scanner calibration are discussed in more detail. An omission of these steps would significantly degrade the deformation analysis and the significance of its results. This holds for all sorts of laser scanner based analyses.

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