ANALYSIS OF FILTERING TECHNIQUES FOR INVESTIGATING LANDSLIDE-INDUCED TOPOGRAPHIC CHANGES IN THE OETZ VALLEY (TYROL, AUSTRIA)

Abstract. Landslides endanger settlements and infrastructure in mountain areas across the world. Monitoring of landslides is therefore essential in order to understand and possibly predict their behavior and potential danger. Terrestrial laser scanning has proven to be a successful tool in the assessment of changes on landslide surfaces due to its high resolution and accuracy. However, it is necessary to classify the 3D point clouds into vegetation and bare-earth points using filtering algorithms so that changes caused by landslide activity can be quantified. For this study, three classification algorithms are compared on an exemplary landslide study site in the Oetz valley in Tyrol, Austria. An optimal set of parameters is derived for each algorithm and their performances are evaluated using different metrics. The volume changes on the study site between the years 2017 and 2019 are compared after the application of each algorithm. The results show that (i) the tested filter techniques perform differently, (ii) their performance depends on their parameterization and (iii) the best-performing parameterization found over the vegetated test area will yield misclassifications on non-vegetated rough terrain. In particular, if only small changes have occurred the choice of the filtering technique and its parameterization play an important role in estimating volume changes.

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Special Issue on “Terrestrial Laser Scanning”: Editors’ Notes

Sensors ◽

10.3390/s19204569 ◽

2019 ◽

Vol 19 (20) ◽

pp. 4569

Author(s):

Joan R. Rosell-Polo ◽

Eduard Gregorio ◽

Jordi Llorens

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Terrestrial Laser Scanning ◽

Point Clouds ◽

Special Issue ◽

Alternative Technologies ◽

Cloud Processing ◽

3D Point Clouds ◽

Point Cloud Processing

In this editorial, we provide an overview of the content of the special issue on “Terrestrial Laser Scanning”. The aim of this Special Issue is to bring together innovative developments and applications of terrestrial laser scanning (TLS), understood in a broad sense. Thus, although most contributions mainly involve the use of laser-based systems, other alternative technologies that also allow for obtaining 3D point clouds for the measurement and the 3D characterization of terrestrial targets, such as photogrammetry, are also considered. The 15 published contributions are mainly focused on the applications of TLS to the following three topics: TLS performance and point cloud processing, applications to civil engineering, and applications to plant characterization.

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Comparing Machine and Deep Learning Methods for Large 3D Heritage Semantic Segmentation

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi9090535 ◽

2020 ◽

Vol 9 (9) ◽

pp. 535

Author(s):

Francesca Matrone ◽

Eleonora Grilli ◽

Massimo Martini ◽

Marina Paolanti ◽

Roberto Pierdicca ◽

...

Keyword(s):

Deep Learning ◽

Cultural Heritage ◽

Laser Scanning ◽

Semantic Segmentation ◽

Point Clouds ◽

Classification Algorithms ◽

Learning Methods ◽

3D Point Clouds ◽

The Subject

In recent years semantic segmentation of 3D point clouds has been an argument that involves different fields of application. Cultural heritage scenarios have become the subject of this study mainly thanks to the development of photogrammetry and laser scanning techniques. Classification algorithms based on machine and deep learning methods allow to process huge amounts of data as 3D point clouds. In this context, the aim of this paper is to make a comparison between machine and deep learning methods for large 3D cultural heritage classification. Then, considering the best performances of both techniques, it proposes an architecture named DGCNN-Mod+3Dfeat that combines the positive aspects and advantages of these two methodologies for semantic segmentation of cultural heritage point clouds. To demonstrate the validity of our idea, several experiments from the ArCH benchmark are reported and commented.

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A sensor skid for precise 3D modeling of production lines

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsannals-ii-5-117-2014 ◽

2014 ◽

Vol II-5 ◽

pp. 117-122 ◽

Cited By ~ 3

Author(s):

J. Elseberg ◽

D. Borrmann ◽

J. Schauer ◽

A. Nüchter ◽

D. Koriath ◽

...

Keyword(s):

3D Modeling ◽

Production Line ◽

Laser Scanning ◽

Terrestrial Laser Scanning ◽

Point Clouds ◽

Production Lines ◽

3D Point Clouds ◽

Laser Scanners ◽

Rapid Characterization

Motivated by the increasing need of rapid characterization of environments in 3D, we designed and built a sensor skid that automates the work of an operator of terrestrial laser scanners. The system combines terrestrial laser scanning with kinematic laser scanning and uses a novel semi-rigid SLAMmethod. It enables us to digitize factory environments without the need to stop production. The acquired 3D point clouds are precise and suitable to detect objects that collide with items moved along the production line.

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Multitemporal Terrestrial Laser Scanning for Marble Extraction Assessment in an Underground Quarry of the Apuan Alps (Italy)

Sensors ◽

10.3390/s19030450 ◽

2019 ◽

Vol 19 (3) ◽

pp. 450 ◽

Cited By ~ 6

Author(s):

Silvia Di Bartolo ◽

Riccardo Salvini

Keyword(s):

Laser Scanning ◽

Morphological Changes ◽

Terrestrial Laser Scanning ◽

Point Clouds ◽

Satellite System ◽

General Purpose ◽

Raw Material ◽

3D Point Clouds ◽

Apuan Alps ◽

Material Extraction

This article focuses on the use of Terrestrial Laser Scanning (TLS) for change detection analysis of multitemporal point clouds datasets. Two topographic surveys were carried out during the years 2016 and 2017 in an underground marble quarry of the Apuan Alps (Italy) combining TLS with Global Navigation Satellite System (GNSS) and Total Station (TS) studies. Multitemporal 3D point clouds were processed and compared with the aim of identifying areas subjected to significant material extraction. Point clouds representing changed areas were converted into triangular meshes in order to compute the volume of extracted material over one year of quarrying activities. General purpose of this work is to show a valid method to examine the morphological changes due to raw material extraction with the focus of highlighting benefits, accuracies and drawbacks. The purpose of the executed survey was that of supporting the planning of quarrying activities in respect of regional rules, safety and commercial reasons.

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MORPHOLOGICAL CHANGES ALONG A DIKE LANDSIDE SLOPE SAMPLED BY 4D HIGH RESOLUTION TERRESTRIAL LASER SCANNING

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xli-b3-227-2016 ◽

2016 ◽

Vol XLI-B3 ◽

pp. 227-232 ◽

Cited By ~ 1

Author(s):

Mónica Herrero-Huertaa ◽

Roderik Lindenbergh ◽

Luc Ponsioen ◽

Myron van Damme

Keyword(s):

High Resolution ◽

Laser Scanning ◽

Morphological Changes ◽

Terrestrial Laser Scanning ◽

Emergency Situation ◽

Point Clouds ◽

Data Sampling ◽

Wave Overtopping ◽

3D Point Clouds ◽

The Impact

Emergence of light detection and ranging (LiDAR) technology provides new tools for geomorphologic studies improving spatial and temporal resolution of data sampling hydrogeological instability phenomena. Specifically, terrestrial laser scanning (TLS) collects high resolution 3D point clouds allowing more accurate monitoring of erosion rates and processes, and thus, quantify the geomorphologic change on vertical landforms like dike landside slopes. Even so, TLS captures observations rapidly and automatically but unselectively. In this research, we demonstrate the potential of TLS for morphological change detection, profile creation and time series analysis in an emergency simulation for characterizing and monitoring slope movements in a dike. The experiment was performed near Schellebelle (Belgium) in November 2015, using a Leica Scan Station C10. Wave overtopping and overflow over a dike were simulated whereby the loading conditions were incrementally increased and 14 successful scans were performed. The aim of the present study is to analyse short-term morphological dynamic processes and the spatial distribution of erosion and deposition areas along a dike landside slope. As a result, we are able to quantify the eroded material coming from the impact on the terrain induced by wave overtopping which caused the dike failure in a few minutes in normal storm scenarios (Q = 25 l/s/m) as 1.24 m3. As this shows that the amount of erosion is measurable using close range techniques; the amount and rate of erosion could be monitored to predict dike collapse in emergency situation. The results confirm the feasibility of the proposed methodology, providing scalability to a comprehensive analysis over a large extension of a dike (tens of meters).

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TERRESTRIAL LASER SCANNING AND SATELLITE DATA IN CULTURAL HERITAGE BUILDING DOCUMENTATION

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlvi-m-1-2021-361-2021 ◽

2021 ◽

Vol XLVI-M-1-2021 ◽

pp. 361-366

Author(s):

A. Karagianni

Keyword(s):

Cultural Heritage ◽

Satellite Imagery ◽

Laser Scanning ◽

Large Scale ◽

Cultural Landscapes ◽

Terrestrial Laser Scanning ◽

Point Clouds ◽

Physical Contact ◽

Surrounding Area ◽

3D Point Clouds

Abstract. Technological advances in the field of information acquisition have led to the development of various techniques regarding building documentation. Among the proposed methods, acquisition of data without being in direct physical contact with the features under investigation could provide valuable information especially in the case of buildings or areas presenting a high cultural value. Satellite or ground-based remote sensing techniques could contribute to the protection, conservation and restoration of cultural heritage buildings, as well as in the interpretation and monitoring of their surrounding area. The increasing interest in the generation of 3D facade models for documentation of the built environment has made laser scanning a valuable tool for 3D data collection. Through the generation of dense 3D point clouds, digitization of building facades could be achieved, offering data that could be used for further processing. Satellite imagery could also contribute to this direction, extending the monitoring possibilities of the buildings’ surrounding area or even providing information regarding change detection in large-scale cultural landscapes. This paper presents the study of a mansion house built in the middle of the 18th century in northwestern Greece, using terrestrial laser scanning techniques for facade documentation, as well as satellite imagery for monitoring and interpretation purposes. The scanning process included multiple external scans of the main facade of the building which were registered using artificial targets in order to form a single colored 3D model. Further process resulted in a model that offers measurement possibilities valuable to future plans and designs for preservation and restoration. Digital processing of satellite imagery provided the extraction of additional enhanced data regarding the physiognomy of the surrounding area.

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Arrangement of terrestrial laser scanner positions for area-wide stem mapping of natural forests

Canadian Journal of Forest Research ◽

10.1139/cjfr-2012-0347 ◽

2013 ◽

Vol 43 (4) ◽

pp. 355-363 ◽

Cited By ~ 23

Author(s):

Jan Trochta ◽

Kamil Král ◽

David Janík ◽

Dušan Adam

Keyword(s):

Laser Scanning ◽

Quantitative Assessment ◽

Recognition Rate ◽

Laser Scanner ◽

Terrestrial Laser Scanning ◽

Point Clouds ◽

Laser Beams ◽

Rough Terrain ◽

Terrestrial Laser Scanner ◽

Natural Forests

With the development of terrestrial laser scanning (TLS) and its applications in forestry, the question arises as to how the scanners should be ideally placed for the best possible data acquisition. We searched for an optimal scanning distance for recognition of stems in natural beech-dominated forests, focusing particularly on the shading effect of tree stems and terrain. Recognised tree stems in TLS point clouds were compared with reference stem maps. A GIS-based visibility simulation was carried out to enhance the quantitative assessment and generalizability of results. The analyses also include the additive effect of multiple scanning positions. Single scans only have a tree recognition rate above 80% up to a distance of 15 m from the scanner; using at least three scanning positions a comparable recognition rate was attained up to 20–25 m. A simulated coverage of a beech-dominated natural forest by laser beams using a 40 m square grid of scanning positions captured at least half of the stem perimeter for more than 90% of trees with a DBH ≥ 10 cm. In sites with rough terrain, the relief configuration has a more significant effect of occlusion than present tree stems.

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MONITORING OF FLUVIAL TRANSPORT IN THE MOUNTAIN RIVER BED USING TERRESTRIAL LASER SCANNING

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xli-b7-523-2016 ◽

2016 ◽

Vol XLI-B7 ◽

pp. 523-528

Author(s):

G. Jozkow ◽

A. Borkowski ◽

M. Kasprzak

Keyword(s):

Laser Scanning ◽

River Flow ◽

Terrestrial Laser Scanning ◽

Point Clouds ◽

Major Axis ◽

Strong Impact ◽

Mountain River ◽

Mountain Areas ◽

Fluvial Transport ◽

River Bed

The fluvial transport is the surface process that has a strong impact on the topography changes, especially in mountain areas. Traditional hydrological measurements usually give a good understanding of the river flow, however, the information of the bedload movement in the rivers is still insufficient. In particular, there is limited knowledge about the movement of the largest clasts, i.e. boulders. This investigation addresses mentioned issues by employing Terrestrial Laser Scanning (TLS) to monitor annual changes of the mountain river bed. The vertical changes were estimated based on the Digital Elevation Model (DEM) of difference (DoD) while transported boulders were identified based on the distances between point clouds and RGB-coloured points. Combined RGB point clouds allowed also to measure 3D displacements of boulders. The results showed that the highest dynamic of the fluvial process occurred between years 2012-2013. Obtained DoD clearly indicated alternating zones of erosion and deposition of the sediment finer fractions in the local sedimentary traps. The horizontal displacement of the rock material in the river bed showed high complexity resulting in the displacement of large boulders (major axis about 0.8 m) for the distance up to 2.3 m.

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