| Bollmann, E., Sailer, R., Briese, C., Stötter, J. & Fritzmann, P. (2011), "Potential of airborne laser scanning for geomorphologic feature and process detection and quantifications in high alpine mountains", Zeitschrift für Geomorphologie. Vol. 55(Suppl. 2), pp. 83-104. |
BibTeX:
@article{Bollmann2011,
author = {Erik Bollmann and Rudolf Sailer and Christian Briese and Johann Stötter and Patrick Fritzmann},
title = {Potential of airborne laser scanning for geomorphologic feature and process detection and quantifications in high alpine mountains},
journal = {Zeitschrift für Geomorphologie},
year = {2011},
volume = {55},
number = {Suppl. 2},
pages = {83--104}
}
|
| Bremer, M., Jochem, A. & Rutzinger, M. (2011), "Comparison of branch extraction for deciduous single trees in leaf-on and leaf-off conditions - An eigenvector based approach for terrestrial laser scanning point clouds", In 1st EARSeL SIG Forestry Workshop: Operational Remote Sensing in Forest Management. Prague, Czech Republic. |
| Abstract: Terrestrial Laser Scanning (TLS) is well suited to acquire high resolution point clouds, which can be used to derive single tree attributes for forestry applications. The processing of TLS point clouds requires the implementation of automated processing chains allowing operational data analysis in 3D. In order to obtain detailed information such as, canopy structure, biomass and leaf area index and their respective changes over time the extracted branch structure of the tree is of particular interest. By separating branches from leafs a more precise estimation of leaf area and wood biomass can be obtained. However, - particularly under leaf-on conditions - the structuring and extraction of branch elements in TLS point clouds is a difficult task. The presented work aims to characterize an experimental framework for an automated processing chain for structuring and classifying TLS point cloud data. The approach allows a detailed derivation of botanic parameters such as branching morphology, timber volume estimates, and leaf area indices. Thereby, a detailed comparison between leaf-off and leaf-on conditions is performed. Branch structure information is derived from a deciduous tree for an example data set, which was acquired in summer (leaf-on) and winter (leaf-off) conditions respectively. We performed a segmentation of tree components inside of the TLS point cloud. For each derived segment the corresponding eigenvectors and eigenvalues were computed. Applying a form-index describing the eigenvalue relationship for each segment a classification into segment shapes has been done. Thereby, elongated segments on branches could be separated from more compact or platy leaf segments. The quality of the extraction results depends on the the relationship between data resolution and tree structure complexity. Additionally the density of leafage is of importance. Therefore, derived branch structures were analysed comparing leaf-off and leaf-on conditions. Considering varying point densities on the one hand and tree structure complexities on the other, the robustness of the presented approach was assessed. It can be shown that major branch structures are derivable in both leaf-on and leaf-off conditions whereby small branches are more difficult to extract under leaf-on conditions. Furthermore, basic morphological differences between leaf-on and leaf-off conditions could be observed for the test data set. |
BibTeX:
@inproceedings{bremer_etal_2011_earsel,
author = {Bremer, M. and Jochem, A. and Rutzinger, M.},
title = {Comparison of branch extraction for deciduous single trees in leaf-on and leaf-off conditions - An eigenvector based approach for terrestrial laser scanning point clouds},
booktitle = {1st EARSeL SIG Forestry Workshop: Operational Remote Sensing in Forest Management},
year = {2011}
}
|
| Fritzmann, P., Bremer, M. & Rutzinger, M. (2011), "Detektion von Waldflächen und Siedlungsstrukturen im alpinen Raum mittels kombinierter Fernerkundungstechnologien", In AGIT Symposium und Fachmesse angewandte Geoinformatik. Salzburg, Austria., pp. accepted. |
BibTeX:
@inproceedings{fritzmann_etal_2011_agit,
author = {Fritzmann, P. and Bremer, M. and Rutzinger, M.},
title = {Detektion von Waldflächen und Siedlungsstrukturen im alpinen Raum mittels kombinierter Fernerkundungstechnologien},
booktitle = {AGIT Symposium und Fachmesse angewandte Geoinformatik},
year = {2011},
pages = {accepted}
}
|
| Fritzmann, P., Höfle, B., Vetter, M., Sailer, R., Stötter, J. & Bollmann, E. (2011), "Surface classification based on multi-temporal airborne LiDAR intensity data in high mountain environments. A case study from Hintereisferner, Austria", Zeitschrift für Geomorphologie. Vol. 55(2), pp. 105-126. |
BibTeX:
@article{Fritzmann2011,
author = {Patrick Fritzmann and Bernhard Höfle and Michael Vetter and Rudolf Sailer and J. Stötter and Erik Bollmann},
title = {Surface classification based on multi-temporal airborne LiDAR intensity data in high mountain environments. A case study from Hintereisferner, Austria},
journal = {Zeitschrift für Geomorphologie},
year = {2011},
volume = {55},
number = {2},
pages = {105--126}
}
|
| Geist, T., Höfle, B., Rutzinger, M., Pfeifer, N. & Stötter, J. (2009), "Laser Scanning - a paradigm change in topographic data acquisition for natural hazard management. In Sustainable Natural Hazard Management in Alpine Environments" , pp. 309-339. Springer. |
BibTeX:
@inbook{geist_etal_2009_springer,
author = {Geist, T. and Höfle, B. and Rutzinger, M. and Pfeifer, N. and Stötter, J.},
title = {Laser Scanning - a paradigm change in topographic data acquisition for natural hazard management. In Sustainable Natural Hazard Management in Alpine Environments},
publisher = {Springer},
year = {2009},
pages = {309-339},
url = {http://www.springer.com/earth+sciences/book/978-3-642-03228-8}
}
|
| Geist, T., Höfle, B., Rutzinger, M. & Stötter, J. (2005), "Der Einsatz von flugzeuggestützten Laserscanner Daten für geowissenschaftliche Untersuchungen in Gebirgsräumen", Photogrammetrie, Fernerkundung, Geoinformation. Vol. 3, pp. 183-190. |
BibTeX:
@article{geist_etal_2005_pfg,
author = {Geist, T. and Höfle, B. and Rutzinger, M. and Stötter, J.},
title = {Der Einsatz von flugzeuggestützten Laserscanner Daten für geowissenschaftliche Untersuchungen in Gebirgsräumen},
journal = {Photogrammetrie, Fernerkundung, Geoinformation},
year = {2005},
volume = {3},
pages = {183-190},
url = {http://www.borntraeger-cramer.de/pubs/books/es/photogramm-172200503-desc.html}
}
|
| Geist, T., Höfle, B., Rutzinger, M. & Stötter, J. (2004), "Analysis of laser scanner data with remote sensing techniques for determining surface characteristics", In International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. Freiburg, Germany. Volume 36(part 8/W2), pp. 297. |
| Abstract: The poster presented gives an overview on background, goals, methods, milestones and expected results of a recently started project at the alpS – Centre for Natural Hazard Management. The aim of the project is the determination of surface characteristics from laser scanner data. A pronounced emphasis is laid on the analysis of the laser signal intensity with modern remote sensing methods. Expected results like the quantification of surface roughness can be used e.g. in modelling of geomorphodynamic processes. |
BibTeX:
@inproceedings{geist_etal_2004_iaprs,
author = {Geist, T. and Höfle, B. and Rutzinger, M. and Stötter, J.},
title = {Analysis of laser scanner data with remote sensing techniques for determining surface characteristics},
booktitle = {International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2004},
volume = {36},
number = {part 8/W2},
pages = {297}
}
|
| Höfle, B., Geist, T., Rutzinger, M. & Pfeifer, N. (2007), "Glacier surface segmentation using airborne laser scanning point cloud and intensity data", In International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. Espoo, Finland. Volume 36(part 3/W52), pp. 195-200. |
| Abstract: As glaciers are good indicators for the regional climate, most of them presently undergo dramatic changes due to climate change. Remote sensing techniques have been widely used to identify glacier surfaces and quantify their change in time. This paper introduces a new method for glacier surface segmentation using solely Airborne Laser Scanning data and outlines an object-based surface classification approach. The segmentation algorithm utilizes both, spatial (x,y,z) and brightness information (signal intensity) of the unstructured point cloud. The observation intensity is used to compute a value proportional to the surface property reflectance – the corrected intensity – by applying the laser range equation. The target classes ice, firn, snow and surface irregularities (mainly crevasses) show a good separability in terms of geometry and reflectance. Region growing is used to divide the point cloud into homogeneous areas. Seed points are selected by variation of corrected intensity in a local neighborhood, i.e. growing starts in regions with lowest variation. Most important features for growing are (i) the local predominant corrected intensity (i.e. the mode) and (ii) the local surface normal. Homogeneity is defined by a maximum deviation of ±5% to the reflectance feature of the segment starting seed point and by a maximum angle of 20° between surface normals of current seed and candidate point. Two-dimensional alpha shapes are used to derive the boundary of each segment. Building and cleaning of segment polygons is performed in the Geographic Information System GRASS. To force spatially near polygons to become neighbors in sense of GIS topology, i.e. share a common boundary, small gaps (<2 m) between polygons are closed. An object-based classification approach is applied to the segments using a rule-based, supervised classification. With the application of the obtained intensity class limits, for ice <49% (of maximum observed reflectance), firn 49-74% and snow ?74%, the glacier surface classification reaches an overall accuracy of 91%. |
BibTeX:
@inproceedings{hoefle_etal_2007_iaprs,
author = {Höfle, B. and Geist, T. and Rutzinger, M. and Pfeifer, N.},
title = {Glacier surface segmentation using airborne laser scanning point cloud and intensity data},
booktitle = {International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2007},
volume = {36},
number = {part 3/W52},
pages = {195-200}
}
|
| Höfle, B., Mücke, W., Dutter, M., Rutzinger, M. & Dorninger, P. (2009), "Detection of building regions using airborne LiDAR : a new combination of raster and point cloud based GIS methods", In Geospatial crossroads @ GI_Forum '09 : proceedings of the geoinformatics forum Salzburg, : Geoinformatics on stage. Salzburg, Austria. July 2009., pp. 66-75. Wichmann. |
BibTeX:
@inproceedings{hoefle_etal_2009_giforum,
author = {Höfle, B. and Mücke, W. and Dutter, M. and Rutzinger, M. and Dorninger, P.},
title = {Detection of building regions using airborne LiDAR : a new combination of raster and point cloud based GIS methods},
booktitle = {Geospatial crossroads @ GI_Forum '09 : proceedings of the geoinformatics forum Salzburg, : Geoinformatics on stage},
publisher = {Wichmann},
year = {2009},
pages = {66-75}
}
|
| Höfle, B., Mandlburger, G., Pfeifer, N., Rutzinger, M. & Bell, R. (2009), "Potential of airborne LiDAR in geomorphology", In Geophysical Research Abstracts. Vienna, Austria. April 2009. Volume 11(EGU2009-4630) |
BibTeX:
@inproceedings{hoefle_etal_2009_egu2,
author = {Höfle, B. and Mandlburger, G. and Pfeifer, N. and Rutzinger, M., and Bell, R.},
title = {Potential of airborne LiDAR in geomorphology},
booktitle = {Geophysical Research Abstracts},
year = {2009},
volume = {11},
number = {EGU2009-4630}
}
|
| Höfle, B., Pfeifer, N., Ressl, C., Rutzinger, M. & Vetter, M. (2008), "Water surface mapping using airborne laser scanning elevation and signal amplitude data", In Geophysical Research Abstracts. Volume 10(EGU2008-A-06897) |
BibTeX:
@inproceedings{hoefle_etal_2008_egu,
author = {Höfle, B. and Pfeifer, N. and Ressl, C. and Rutzinger, M. and Vetter, M.},
title = {Water surface mapping using airborne laser scanning elevation and signal amplitude data},
booktitle = {Geophysical Research Abstracts},
year = {2008},
volume = {10},
number = {EGU2008-A-06897}
}
|
| Höfle, B. & Rutzinger, M. (2011), "Topographic airborne LiDAR in geomorphology: A technological perspective", Annals of Geomorphology. Vol. 55(2), pp. 1-29. |
| Abstract: Airborne LiDAR, also referred to as Airborne Laser Scanning, is widely used for high-resolution topographic data acquisition with sub-meter planimetric and vertical accuracy. This contribution gives a review of recent developments of LiDAR systems (e.g. full-waveform LiDAR) and advances in data processing and analysis for geomorphological applications. An overview of applications in geomorphology and related fields using different LiDAR data products (e.g. Digital Terrain Model and 3D point cloud) is given, indicating a great variety of fields of applications and data analysis approaches. These applications range from visual interpretation of LiDAR derivatives (e.g. shaded relief map) to semi-automatic geomorphological mapping and fully automatic object detection (e.g. surface discontinuities). A quantitative analysis of the temporal trend of peer-reviewed journal publications confirms the increased consideration of airborne LiDAR data for mapping, modeling and exploiting Earth surface processes and landforms. Almost 50% of the papers of the last 15 years were published in the last two years 2008 and 2009. Airborne LiDAR technology is developing rapidly leading to both a great opportunity and challenge for integrating new technological developments into existing workflows and stimulating new innovative approaches. |
BibTeX:
@article{hoefle_rutzinger_2011,
author = {Höfle, B. and Rutzinger, M.},
title = {Topographic airborne LiDAR in geomorphology: A technological perspective},
journal = {Annals of Geomorphology},
year = {2011},
volume = {55},
number = {2},
pages = {1-29}
}
|
| Höfle, B. & Rutzinger, M. (2011), "Topographic airborne LiDAR in geomorphology: A technological perspective", Annals of Geomorphology. , pp. accepted. |
| Abstract: Airborne LiDAR, also referred to as Airborne Laser Scanning, is widely used for high-resolution topographic data acquisition with sub-meter planimetric and vertical accuracy. This contribution gives a review of recent developments of LiDAR systems (e.g. full-waveform LiDAR) and advances in data processing and analysis for geomorphological applications. An overview of applications in geomorphology and related fields using different LiDAR data products (e.g. Digital Terrain Model and 3D point cloud) is given, indicating a great variety of fields of applications and data analysis approaches. These applications range from visual interpretation of LiDAR derivatives (e.g. shaded relief map) to semi-automatic geomorphological mapping and fully automatic object detection (e.g. surface discontinuities). A quantitative analysis of the temporal trend of peer-reviewed journal publications confirms the increased consideration of airborne LiDAR data for mapping, modeling and exploiting Earth surface processes and landforms. Almost 50% of the papers of the last 15 years were published in the last two years 2008 and 2009. Airborne LiDAR technology is developing rapidly leading to both a great opportunity and challenge for integrating new technological developments into existing workflows and stimulating new innovative approaches. |
BibTeX:
@article{hoefle_rutzinger_2011,
author = {Höfle, B. and Rutzinger, M.},
title = {Topographic airborne LiDAR in geomorphology: A technological perspective},
journal = {Annals of Geomorphology},
year = {2011},
pages = {accepted}
}
|
| Höfle, B., Rutzinger, M., Geist, T. & Stötter, J. (2006), "Using airborne laser scanning data in urban data management - set up of a flexible information system with open source componentents", In Proceedings UDMS 2006: Urban Data Management Symposium. Aalborg, Denmark., pp. digital media. |
BibTeX:
@inproceedings{hoefle_etal_2006_udms,
author = {Höfle, B. and Rutzinger, M. and Geist, T. and Stötter, J.},
title = {Using airborne laser scanning data in urban data management - set up of a flexible information system with open source componentents},
booktitle = {Proceedings UDMS 2006: Urban Data Management Symposium},
year = {2006},
pages = {digital media}
}
|
| Höfle, B., Rutzinger, M. & Pfeifer, N. (2006), "Terrestrial Laser Scanner Optech ILRIS 3D - Experiment on the angle of incidence and recorded intensity". Institute of Geography, University of Innsbruck, 2006. |
BibTeX:
@techreport{hoefle_etal_2006_report,
author = {Höfle, B. and Rutzinger, M. and Pfeifer, N.},
title = {Terrestrial Laser Scanner Optech ILRIS 3D - Experiment on the angle of incidence and recorded intensity},
year = {2006}
}
|
| Höfle, B., Sailer, R., Vetter, M., Rutzigner, M. & Pfeifer, N. (2009), "Glacier surface feature detection and classification from airborne LiDAR data", In Geophysical research abstracts. April 2009. Volume 11(EGU2009-4665) |
BibTeX:
@inproceedings{hoefle_etal_2009_egu1,
author = {Höfle, B. and Sailer, R. and Vetter, M. and Rutzigner, M. and Pfeifer, N.},
title = {Glacier surface feature detection and classification from airborne LiDAR data},
booktitle = {Geophysical research abstracts},
year = {2009},
volume = {11},
number = {EGU2009-4665}
}
|
| Ivánová, I., Huisman, O., de By, R., Rutzinger, M., Bakker, W. & Feringa, W. (2010), "Developing a distance education programming skills course for geo-information science and Earth observation students", In International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. Enschede, The Netherlands. June 2010. Volume 38(part 6), pp. 62-67. |
| Abstract: This paper describes the development of a distance education course on programming skills. The purpose of this course is twofold: first, it supports ITC’s Joint- Education Projects (JEPs) currently underway in several developing countries, and secondly, it broadens the target market for our educational services. One of the key aims in teaching programming skills using any programming language is to teach students how to approach computational problem-solving in a structured and logical way. The challenge in doing so is how to develop adequate learning resources on the programming fundamentals, which are both intuitive and functional. Drawing upon several years of experience of teaching programming skills at the Faculty of Geo-Information Science and Earth Observation of the University of Twente (ITC, The Netherlands), we designed a course based on an interactive learning environment, developed for a previous distance education course (Ivánová et al. 2008), but significantly extended to support new content. The programming language taught is Python, which is a general-purpose, open-source computer language well-suited for use in the hybrid context of databases, Geographic Information Systems, image processing, and web applications. It is well-known for its lean syntax, which allows the novice student to devote more time to algorithmic and programming fundamentals. The course is designed around an interactive learning infrastructure. It is built in an environment that seamlessly integrates the Python environment (= program scripting and command line) and the teaching environment (= lecture material, exercise environment, and a textbook). The course material is developed for plug-and-play deployment on a student’s PC, reducing the initial requirements on installation and optimization of the work environment. Although the nature of studying a programming language is intrinsically selfstudy, this plug-and-play solution also allows components of the course to be deployed in a face-to-face set-up, as well as in distance education mode. This type of integrated learning environment currently does not exist anywhere; existing solutions are mostly in the form of isolated tutorials or books. From a didactic perspective, the course presented here is a system of self-instructional learning objects, allowing students to proceed in their own location, in their own time, and at their own pace, with an extensive direct feedback embedded in the course materials. Most of the course content is based upon open-source materials – the textbook and some of the exercises. However, we are extending these materials to tailor the course better to geoinformation science students by adding material (in the form of lessons, as well as adding a chapter to the book itself). By doing so, we release the new chapter into the open-source realm through creative commons licensing. |
BibTeX:
@inproceedings{ivanova_etal_2010,
author = {Ivánová, I. and Huisman, O. and de By, R. and Rutzinger, M. and Bakker, W. and Feringa, W.},
title = {Developing a distance education programming skills course for geo-information science and Earth observation students},
booktitle = {International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2010},
volume = {38},
number = {part 6},
pages = {62-67}
}
|
| Jörg, P., Fromm, R., Sailer, R. & Schaffhauser, A. (2006), "Measuring snow depth with a Terrestrial Laser Ranging System", ISSW 2006, Telluride, Colorado, USA. , pp. 452-460. |
BibTeX:
@article{Joerg2006,
author = {P. Jörg and R. Fromm and R. Sailer and A. Schaffhauser},
title = {Measuring snow depth with a Terrestrial Laser Ranging System},
journal = {ISSW 2006, Telluride, Colorado, USA},
year = {2006},
pages = {452--460}
}
|
| Jochem, A., Höfle, B., Hollaus, M. & Rutzinger, M. (2009), "Object detection in airborne LIDAR data for improved solar radiation modeling in urban areas", In International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. Paris, France. September 2009. Volume 38(part 3/W8), pp. 1-6. |
| Abstract: In times of higher market prices of fossil fuels and to meet the increasingly environmental and economic threads of climate change renewable energy must play a major role for global energy supply. This paper focuses on a new method for fully automated solar potential assessment of roof planes from airborne LiDAR data and uses the full 3D information for both, roof plane detection and solar potential analysis. An image based candidate region detection algorithm reduces the data volume of the point cloud and identifies potential areas containing buildings with high completeness (97%). Three dimensional roof planes are extracted from the building candidate regions and their aspect and slope are calculated. The horizon of each roof plane is calculated within the 3D point cloud and thus shadowing effects of nearby objects such as vegetation, roofs, chimneys, dormers etc. are respected in a proper way. In contrast to other objects such as walls or buildings vegetation is characterized by transparent properties. Thus, in a further step vegetation is detected within the remaining non-roof points and transparent shadow values are introduced by calculating a local transparency measure averaged per tree segment. The following solar potential analysis is performed for regularly distributed roof points and results in both, (i) the annual sum of the direct and diffuse radiation for each roof plane and (ii) in a detailed information about the distribution of radiation within one roof. By calculating a clear sky index, cloud cover effects are considered using data from a nearby meteorological ground station. |
BibTeX:
@inproceedings{jochem_etal_2009_aiprs,
author = {Jochem, A. and Höfle, B. and Hollaus, M. and Rutzinger,M.},
title = {Object detection in airborne LIDAR data for improved solar radiation modeling in urban areas},
booktitle = {International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2009},
volume = {38},
number = {part 3/W8},
pages = {1-6}
}
|
| Jochem, A., Höfle, B., Rutzinger, M. & Pfeifer, N. (2009), "Automatic roof plane detection and analysis in airborne LIDAR point clouds for solar potential assessment", Sensors. Vol. 9(7), pp. 5241-5262. |
| Abstract: A relative height threshold is defined to separate potential roof points from the point cloud, followed by a segmentation of these points into homogeneous areas fulfilling the defined constraints of roof planes. The normal vector of each laser point is an excellent feature to decompose the point cloud into segments describing planar patches. An objectbased error assessment is performed to determine the accuracy of the presented classification. It results in 94.4% completeness and 88.4% correctness. Once all roof planes are detected in the 3D point cloud, solar potential analysis is performed for each point. Shadowing effects of nearby objects are taken into account by calculating the horizon of each point within the point cloud. Effects of cloud cover are also considered by using data from a nearby meteorological station. As a result the annual sum of the direct and diffuse radiation for each roof plane is derived. The presented method uses the full 3D information for both feature extraction and solar potential analysis, which offers a number of new applications in fields where natural processes are influenced by the incoming solar radiation (e.g., evapotranspiration, distribution of permafrost). The presented method detected fully automatically a subset of 809 out of 1,071 roof planes where the arithmetic mean of the annual incoming solar radiation is more than 700 kWh/m2. |
BibTeX:
@article{jochem_etal_2009_sensors,
author = {Jochem, A. and Höfle, B. and Rutzinger, M. and Pfeifer, N.},
title = {Automatic roof plane detection and analysis in airborne LIDAR point clouds for solar potential assessment},
journal = {Sensors},
year = {2009},
volume = {9},
number = {7},
pages = {5241-5262},
doi = {http://dx.doi.org/10.3390/s90705241}
}
|
| Jochem, A., Hollaus, M., Rutzinger, M. & Höfle, B. (2011), "Estimation of aboveground biomass in alpine forests: a semi-empirical approach considering canopy transparency derived from airborne LiDAR data", Sensors. Vol. 11(1), pp. 278-295. |
| Abstract: In this study, a semi-empirical model that was originally developed for stem volume estimation is used for aboveground biomass (AGB) estimation of a spruce dominated alpine forest. The reference AGB of the available sample plots is calculated from forest inventory data by means of biomass expansion factors. Furthermore, the semi-empirical model is extended by three different canopy transparency parameters derived from airborne LiDAR data. These parameters have not been considered for stem volume estimation until now and are introduced in order to investigate the behavior of the model concerning AGB estimation. The developed additional input parameters are based on the assumption that transparency of vegetation can be measured by determining the penetration of the laser beams through the canopy. These parameters are calculated for every single point within the 3D point cloud in order to consider the varying properties of the vegetation in an appropriate way. Exploratory Data Analysis (EDA) is performed to evaluate the influence of the additional LiDAR derived canopy transparency parameters for AGB estimation. The study is carried out in a 560 km2 alpine area in Austria, where reference forest inventory data and LiDAR data are available. The investigations show that the introduction of the canopy transparency parameters does not change the results significantly according to R2 (R2 = 0.70 to R2 = 0.71) in comparison to the results derived from, the semi-empirical model, which was originally developed for stem volume estimation. |
BibTeX:
@article{jochem_etal_2011_sensors,
author = {Jochem, A. and Hollaus, M. and Rutzinger, M. and Höfle, B.},
title = {Estimation of aboveground biomass in alpine forests: a semi-empirical approach considering canopy transparency derived from airborne LiDAR data},
journal = {Sensors},
year = {2011},
volume = {11},
number = {1},
pages = {278-295},
doi = {http://dx.doi.org/10.3390/s110100278}
}
|
| Jochem, A., Hollaus, M., Rutzinger, M., Höfle, B., Schadauer, K. & Maier, B. (2010), "Estimation of aboveground biomass using airborne LiDAR data", In Proceedings of Silvilaser 2010, the 10th International Conference on LiDAR Applications for Assessing Forest Ecosystems. Freiburg, Germany. September 2010., pp. digital media. |
| Abstract: In this study a semi-empirical model that was originally developed for stem volume estimation is used for aboveground biomass (AGB) estimation. The semi-empirical model is based on the relative heights of first echo LiDAR point cloud data and assumes a linear relationship between AGB and canopy volume. However, the usage of point cloud data leads to a computationally demanding task when processing large point cloud datasets for the generation of area-wide AGB maps. In the presented study the effects of using rasterized LiDAR data as input for the AGB model are investigated in order to speed up processing and to make use of the model on large spatial datasets. The canopy volumes are calculated from a Canopy Height Model (CHM). The optimum resolution of the CHM is determined by analyzing the effects of varying cell sizes (1.0 m, 1.5 m, 2.0 m, 3.0 m) on the achievable accuracies. Calibrating the model with rasterized input data having a spatial resolution of 2.0 m instead of using first echo point cloud data leads to a slight increase of the coefficient of determination (R2 = 0.70 to R2 = 0.72) and a slight decrease of the standard deviation of the prediction errors. For calibrating the model reference AGB is calculated per sample plot from local forest inventory data by means of averaged weighted (according to tree species and age class composition) extension factors. The influence of using rasterized LiDAR input data on the achievable accuracy of the assessed AGB is investigated for a coniferous dominated study area in Vorarlberg, Austria. |
BibTeX:
@inproceedings{jochem_2010,
author = {Jochem, A. and Hollaus, M. and Rutzinger, M. and Höfle, B. and Schadauer, K. and Maier, B.},
title = {Estimation of aboveground biomass using airborne LiDAR data},
booktitle = {Proceedings of Silvilaser 2010, the 10th International Conference on LiDAR Applications for Assessing Forest Ecosystems},
year = {2010},
pages = {digital media}
}
|
| Jochem, A., Höfle, B. & Rutzigner, M. (2011), "Extraction of vertical walls from mobile laser scanning data for solar potential assessment", Remote Sensing. Vol. 3, pp. 650-667. |
| Abstract: In recent years there has been an increasing demand among home owners for cost effective sustainable energy production such as solar energy to provide heating and electricity. A lot of research has focused on the assessment of the incoming solar radiation on roof planes acquired by, e.g., Airborne Laser Scanning (ALS). However, solar panels can also be mounted on building facades in order to increase renewable energy supply. Due to limited reflections of points from vertical walls, ALS data is not suitable to perform solar potential assessment of vertical building facades. This paper focuses on a new method for automatic solar radiation modeling of facades acquired by Mobile Laser Scanning (MLS) and uses the full 3D information of the point cloud for both the extraction of vertical walls covered by the survey and solar potential analysis. Furthermore, a new method is introduced determining the interior and exterior face, respectively, of each detected wall in order to calculate its slope and aspect angles that are of crucial importance for solar potential assessment. Shadowing effects of nearby objects are considered by computing the 3D horizon of each point of a facade segment within the 3D point cloud. |
BibTeX:
@article{jochem_etal_2011_rs,
author = {Jochem, A. and Höfle, B. and Rutzigner, M.},
title = {Extraction of vertical walls from mobile laser scanning data for solar potential assessment},
journal = {Remote Sensing},
year = {2011},
volume = {3},
pages = {650-667},
doi = {Quality analysis on 3D building models reconstructed from airborne laser scanning data}
}
|
| Jochem, A., Höfle, B., Wichmann, V., Rutzinger, M. & Zipf, A. (2011), "Area-wide roof plane segmentation in airborne LiDAR point clouds", Computers, Environment and Urban Systems. , pp. in press. |
| Abstract: Most algorithms performing segmentation of 3D point cloud data acquired by, e.g. Airborne Laser Scanning (ALS) systems are not suitable for large study areas because the huge amount of point cloud data cannot be processed in the computer’s main memory. In this study a new workflow for seamless automated roof plane detection from ALS data is presented and applied to a large study area. The design of the workflow allows area-wide segmentation of roof planes on common computer hardware but leaves the option open to be combined with distributed computing (e.g. cluster and grid environments). The workflow that is fully implemented in a Geographical Information System (GIS) uses the geometrical information of the 3D point cloud and involves four major steps: (i) The whole dataset is divided into several overlapping subareas, i.e. tiles. (ii) A raster based candidate region detection algorithm is performed for each tile that identifies potential areas containing buildings. (iii) The resulting building candidate regions of all tiles are merged and those areas overlapping one another from adjacent tiles are united to a single building area. (iv) Finally, three dimensional roof planes are extracted from the building candidate regions and each region is treated separately. The presented workflow reduces the data volume of the point cloud that has to be analyzed significantly and leads to the main advantage that seamless area-wide point cloud based segmentation can be performed without requiring a computationally intensive algorithm detecting and combining segments being part of several subareas (i.e. processing tiles). A reduction of 85% of the input data volume for point cloud segmentation in the presented study area could be achieved, which directly decreases computation time. |
BibTeX:
@article{jochem_2011_ceus,
author = {Jochem, A. and Höfle, B. and Wichmann, V. and Rutzinger, M. and Zipf, A.},
title = {Area-wide roof plane segmentation in airborne LiDAR point clouds},
journal = {Computers, Environment and Urban Systems},
year = {2011},
pages = {in press}
}
|
| Kringer, K., Tusch, M., Geitner, C., Meißl, G. & Rutzinger, M. (2009), "Analysis of airborne LiDAR as a basis for digital soil mapping in Alpine areas", In Geophysical Reseach Abstracts. Vienna, Austria. April 2009. Volume 11(EGU2009-10967) |
BibTeX:
@inproceedings{kringer_etal_2009_egu,
author = {Kringer, K. and Tusch, M. and Geitner, C. and Meißl, G. and Rutzinger, M.},
title = {Analysis of airborne LiDAR as a basis for digital soil mapping in Alpine areas},
booktitle = {Geophysical Reseach Abstracts},
year = {2009},
volume = {11},
number = {EGU2009-10967}
}
|
| Kringer, K., Tusch, M., Geitner, C., Rutzinger, M., Wiegand, C. & Meißl, G. (2009), "Geomorphometric Analyses of LiDAR Digital Terrain Models as Input for Digital Soil Mapping", In Proceedings of Geomorphometry 2009. Zürich, Switzerland. September 2009., pp. 74-81. |
BibTeX:
@inproceedings{kringer_etal_2009_geomorphometry,
author = {Kringer, K. and Tusch, M. and Geitner, C. and Rutzinger, M. and Wiegand, C. and Meißl, G.},
title = {Geomorphometric Analyses of LiDAR Digital Terrain Models as Input for Digital Soil Mapping},
booktitle = {Proceedings of Geomorphometry 2009},
year = {2009},
pages = {74-81}
}
|
| Luzi, G., Pieraccini, M., Noferini, L., Mecatti, D., Macaluso, G., Atzeni, C., Jörg, P. & Sailer, R. (2007), "Microwave Interferometric Measurements Over a Snow Covered Slope: An Experimental data Collection in Tyrol (Austria)", Proceedings of IGARSS 2007 Barcelona, Spain.. , pp. 1452 - 1455. |
BibTeX:
@article{Luzi2007,
author = {G. Luzi and M. Pieraccini and L. Noferini and D. Mecatti and G. Macaluso and C. Atzeni and P. Jörg and R. Sailer},
title = {Microwave Interferometric Measurements Over a Snow Covered Slope: An Experimental data Collection in Tyrol (Austria)},
journal = {Proceedings of IGARSS 2007 Barcelona, Spain.},
year = {2007},
pages = {1452 -- 1455},
doi = {http://dx.doi.org/10.1109/IGARSS.2007.4423081}
}
|
| Maukisch, M., Petrini-Monteferri, F., Stötter, J. & Rutzinger, M. (2007), "Algorithms for the extraction of geologic lineaments from airborne laser scanning data", In Proceedings of the International Conference 'Managing Alpine Future'. Innsbruck, Austria. October 2007. |
| Abstract: Linear structures on the earth’s surface, that differ in a well defined small range from a straight line are called lineaments. The basis for lineament mapping is a digital terrain model derived on the basis of airborne laser scanning data. Laser scanning is an operational method for collecting high resolution and accurate height and reflection information of the earth surface. Tree and scrub vegetation is partly penetrated by the laser beam, so that surface structures covered by vegetation can be mapped. For the purpose of lineament extraction from laser scanning data different concepts have already been developed and implemented using e.g. the Software GRASS GIS. Enhancements of this concept will allow multi-scale analysis. This means that changing scales will be considered for the lineament extraction so that the resulting line structures can be classified. |
BibTeX:
@inproceedings{maukisch_etal_2007_maf,
author = {Maukisch, M. and Petrini-Monteferri, F. and Stötter, J. and Rutzinger, M.},
title = {Algorithms for the extraction of geologic lineaments from airborne laser scanning data},
booktitle = {Proceedings of the International Conference 'Managing Alpine Future'},
year = {2007}
}
|
| Pfeifer, N., Höfle, B., Briese, C., Rutzinger, M. & Haring, A. (2008), "Analysis of the backscattered energy in terrestrial laser scanning data", In International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. Beijing, China. July 2008. Volume 37, pp. 1045-1051. |
| Abstract: Terrestrial laser scanning provides a point cloud, but usually also the “intensity” values are available. These values are mainly influenced by the distance from sensor to object and by the object’s reflection properties. We demonstrate that it is possible to retrieve these reflection properties from the observed range and the intensity value. An experiment with targets of known reflectivity behaviour is described. Retrieving object reflectivity is also demonstrated for these targets in another experiment, which was not used to determine the functional relationship between range, reflectivity, and intensity. The Lidar equation describes the received optical power in terms of the emitted power, range, and target properties. Nonetheless, the intensity values do not follow this prescribed behaviour. Therefore, data driven approaches are used, allowing a better prediction of the observed intensity from the range and reflectivity of the targets. For a Riegl LMS-Z420i and an Optech ILRIS 3D these experiments were performed. Both scanners measure range by the travel time of a pulse. In our experiments, the reflectivity can be estimated from the laser scanning data with a standard deviation of 6% or better. This demonstrates the potential for retrieving material properties of natural surfaces, too. |
BibTeX:
@inproceedings{pfeifer_etal_2008_iaprs,
author = {Pfeifer, N. and Höfle, B. and Briese, C. and Rutzinger, M. and Haring, A.},
title = {Analysis of the backscattered energy in terrestrial laser scanning data},
booktitle = {International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2008},
volume = {37},
pages = {1045-1051}
}
|
| Pfeifer, N., Rutzinger, M., Rottensteiner, F., Mücke, W. & Hollaus, M. (2007), "Extraction of building footprints from airborne laser scanning: Comparison and validation techniques", In Joint IEEE-GRSS/ISPRS Workshop on Remote Sensing and Data Fusion over Urban Areas, Urban 2007. Paris, France., pp. digital media. |
| Abstract: Many applications in urban planning and analysis require the position and extent of buildings, the so-called building footprint. Cadastral maps acquired by ground based surveying are often not up-to-date or may not be available at all. Airborne laser scanning, on the other hand, offers the possibility to detect the roof outlines in an automated manner. This subject has been researched in the previous years, but a final comparison of the quality of these algorithms has not been performed. Additionally, the methods for assessing the quality of building footprint extraction should consider the special characteristics of airborne laser scanning data. This paper gives an overview of the algorithms developed for the task of house detection from airborne laser scanning and evaluates two algorithms experimentally. The methods of quality assessment are discussed and next to the standard method of pixel based comparison the object based comparison is studied, providing more insight. |
BibTeX:
@inproceedings{pfeifer_etal_2007_urban,
author = {Pfeifer, N. and Rutzinger, M. and Rottensteiner, F. and Mücke, W. and Hollaus, M.},
title = {Extraction of building footprints from airborne laser scanning: Comparison and validation techniques},
booktitle = {Joint IEEE-GRSS/ISPRS Workshop on Remote Sensing and Data Fusion over Urban Areas, Urban 2007},
year = {2007},
pages = {digital media},
note = {Invited paper},
doi = {http://dx.doi.org/10.1109/URS.2007.371854}
}
|
| Rutzigner, M., Höfle, B., Vetter, M. & Pfeifer, N. (2011), "Digital terrain models from airborne laser scanning for the automatic extraction of natural and anthropogenic linear structures In: Geomorphological Mapping: a professional handbook of techniques and applications" , pp. accepted. Elsevier. |
| Abstract: Digital Terrain Models (DTMs) acquired from Airborne Laser Scanning (ALS) are available for many mountainous regions. ALS has the capability to penetrate high vegetation, hence, high resolution DTMs can be derived even in forested areas. This terrain information can be used in various geo-related applications such as hydrology, natural hazard process modelling, and geomorphological mapping. The high resolution of ALS DTMs shows both natural and anthropogenic terrain features such as erosion scarps, geological lineaments, walking paths, and roads. Anthropogenic structure lines often subdivide the terrain into artificial units, therefore, to be able to describe the natural geomorphologic feature as a unit in its original appearance, anthropogenic and natural features have to be separated. Without this modelling, several applications suffer from using ALS data. Standard algorithms previously developed for coarser DTMs are not adapted to the implicit feature representation in the highly detailed terrain description. The classification approach presented here separates road features from geomorphologic line structures based on their slope, curvature and shape properties in three different test sites in the Austrian Alps highlighting different geomorphological situations. The comparison to a road reference map shows the feasibility of the developed workflow. The importance of detecting anthropogenic structures for geomorphological investigations is demonstrated by calculating a line density map, which indicates geomorphological activity on sloped terrain. |
BibTeX:
@inbook{rutzinger_etal_2011,
author = {Rutzigner, M. and Höfle, B. and Vetter, M. and Pfeifer, N.},
title = {Digital terrain models from airborne laser scanning for the automatic extraction of natural and anthropogenic linear structures In: Geomorphological Mapping: a professional handbook of techniques and applications},
publisher = {Elsevier},
year = {2011},
pages = {accepted}
}
|
| Rutzinger, M. (2009), "Topographic laser ranging and scanning : principles and processing / J. Shan and C.K. Toth, London : Taylor and Francis, 2008. ISBN 978-1-4200-5142-1 : book review", International journal of applied earth observation and geoinformation. Vol. 11(5), pp. 368-369. |
BibTeX:
@article{rutzinger_2009_jag,
author = {Rutzinger, M.},
title = {Topographic laser ranging and scanning : principles and processing / J. Shan and C.K. Toth, London : Taylor and Francis, 2008. ISBN 978-1-4200-5142-1 : book review},
journal = {International journal of applied earth observation and geoinformation},
year = {2009},
volume = {11},
number = {5},
pages = {368-369},
doi = {http://dx.doi.org/10.1016/j.jag.2009.05.001}
}
|
| Rutzinger, M. (2008), "Object detection in airborne laser scanning data in urban environments". School: Institute of Geography, University of Innsbruck. Innsbruck, Austria, August, 2008. |
| Abstract: In the 1990s airborne laser scanning (ALS) became the operational method for areawide high resolution digital terrain model (DTM) generation. To expose the potential of the data for further applications such as urban planning, process modelling, and visualization, the acquired data have to be grouped to classes representing objects of interest. In this thesis object-based algorithms are developed using open source tools to segment and classify objects in urban environments with focus on buildings and high vegetation. The algorithms work in both, raster and 3D point cloud domain without using ancillary data such as multi-spectral imagery or preprocessed data such as DTMs. The methods are developed for data from discrete return recording systems but especially for vegetation analysis also additional attributes from full waveform recording systems are considered. The developed object-based approaches – working in the raster, on a point cloud, or using a combination of both – overcome several limitations of conventional classification concepts. On the one hand object-based approaches reduce the ambiguity if classifying the single entities (i.e. the raster cell and the laser echo) directly, by segmenting the input data to object-primitives. Segments represent parts of real world objects, which are grouped to the object of interest in the final classification step. On the other hand the amount of data to be classified is reduced by either (i) the sequent combination of segmentation and classification or (ii) the combined usage of OBIA (object-based image analysis) and OBPA (object-based point cloud analysis). As a first part of this thesis, approaches for the detection of building footprints using digital surface models (DSMs) are introduced. A vegetation mask is required and calculated from the difference of the first and last reflection of the laser beam. Then building segments are delineated and classified in order to derive building footprints. The developed OBIA building classification method is compared to a Dempster-Shafer detection method fusing ALS and multi-spectral data. The developed object-based error measures are compared to pixel-based measures in order to critically reflect the possibilities of describing detection success using object-based classification methods. Further building analysis by a combined approach of OBIA and OBPA first derives building footprints in the raster domain and then delineates rooftops from the 3D point cloud. Parameters of roof faces, such as the mean slope, are calculated from the point cloud directly. This is a basic information for further applications, such as the planning of photovoltaic locations and snow capacity modelling. The further potential of 3D point cloud analysis for urban object classification is investigated by calculating roughness and point density measures, which are found to be suitable to segment and characterize high vegetation. Finally, these findings are used to classify high vegetation using full-waveform ALS data. It can be shown that segments from 3D region growing using echo width are suitable object primitives to separate trees and shrubs from buildings and terrain echoes. Furthermore it is possible to distinguish buildings covered or connected to trees. It can be shown in this thesis that ALS data have a high potential for 3D land cover classification in urban areas. The thesis contributes to object detection with focus on point cloud classification by introducing the OBPA concept, which allows an accurate delineation of objects as well as fast and efficient classification. This will improve DTM generation and closes the gap between the ALS point cloud and its integration into 3D applications. |
BibTeX:
@phdthesis{rutzinger_2008_phd,
author = {Rutzinger, M.},
title = {Object detection in airborne laser scanning data in urban environments},
school = {Institute of Geography, University of Innsbruck},
year = {2008}
}
|
| Rutzinger, M. (2005), "Identifikation und Klassifikation von Objekten und Oberflächeneigenschaften aus Laserscannerdaten Auswertestrategien mit eCognition für forstliche Fragestellungen". School: Institute of Geography, University of Innsbruck. Innsbruck, Austria, February, 2005. |
BibTeX:
@mastersthesis{rutzinger_2005_msc,
author = {Rutzinger, M.},
title = {Identifikation und Klassifikation von Objekten und Oberflächeneigenschaften aus Laserscannerdaten Auswertestrategien mit eCognition für forstliche Fragestellungen},
school = {Institute of Geography, University of Innsbruck},
year = {2005}
}
|
| Rutzinger, M., Geist, T., Heller, A. & Stötter, J. (2005), "Methoden zur Waldmaskenerstellung aus Laserscannerdaten mit eCognition", In Angewandte Geoinformatik 2005, Beiträge zum 17. AGIT-Symposium Salzburg. Salzburg, Austria., pp. 596-604. |
BibTeX:
@inproceedings{rutzinger_etal_2005_agit,
author = {Rutzinger, M. and Geist, T. and Heller, A. and Stötter, J.},
title = {Methoden zur Waldmaskenerstellung aus Laserscannerdaten mit eCognition},
booktitle = {Angewandte Geoinformatik 2005, Beiträge zum 17. AGIT-Symposium Salzburg},
year = {2005},
pages = {596-604}
}
|
| Rutzinger, M., Höfle, B., Geist, T. & Stötter, J. (2006), "Object-based building detection based on airborne laser scanning data within GRASS GIS environment", In Proceedings UDMS 2006: Urban Data Management Symposium. Aalborg, Denmark., pp. digital media. |
BibTeX:
@inproceedings{rutzinger_etal_2006_udms,
author = {Rutzinger, M. and Höfle, B. and Geist, T. and Stötter, J.},
title = {Object-based building detection based on airborne laser scanning data within GRASS GIS environment},
booktitle = {Proceedings UDMS 2006: Urban Data Management Symposium},
year = {2006},
pages = {digital media}
}
|
| Rutzinger, M., Höfle, B., Hollaus, M. & Pfeifer, N. (2008), "Object-Based Point Cloud Analysis of Full-Waveform Airborne Laser Scanning Data for Urban Vegetation Classification", Sensors. Vol. 8(8), pp. 4505-4528. |
| Abstract: Airborne laser scanning (ALS) is a remote sensing technique well-suited for 3D vegetation mapping and structure characterization because the emitted laser pulses are able to penetrate small gaps in the vegetation canopy. The backscattered echoes from the foliage, woody vegetation, the terrain, and other objects are detected, leading to a cloud of points. Higher echo densities (> 20 echoes/m2) and additional classification variables from full-waveform (FWF) ALS data, namely echo amplitude, echo width and information on multiple echoes from one shot, offer new possibilities in classifying the ALS point cloud. Currently FWF sensor information is hardly used for classification purposes. This contribution presents an object-based point cloud analysis (OBPA) approach, combining segmentation and classification of the 3D FWF ALS points designed to detect tall vegetation in urban environments. The definition tall vegetation includes trees and shrubs, but excludes grassland and herbage. In the applied procedure FWF ALS echoes are segmented by a seeded region growing procedure. All echoes sorted descending by their surface roughness are used as seed points. Segments are grown based on echo width homogeneity. Next, segment statistics (mean, standard deviation, and coefficient of variation) are calculated by aggregating echo features such as amplitude and surface roughness. For classification a rule base is derived automatically from a training area using a statistical classification tree. To demonstrate our method we present data of three sites with around 500,000 echoes each. The accuracy of the classified vegetation segments is evaluated for two independent validation sites. In a point-wise error assessment, where the classification is compared with manually classified 3D points, completeness and correctness better than 90% are reached for the validation sites. In comparison to many other algorithms the proposed 3D point classification works on the original measurements directly, i.e. the acquired points. Gridding of the data is not necessary, a process which is inherently coupled to loss of data and precision. The 3D properties provide especially a good separability of buildings and terrain points respectively, if they are occluded by vegetation. |
BibTeX:
@article{rutzinger_etal_2008_sensors,
author = {Rutzinger, M. and Höfle, B. and Hollaus, M. and Pfeifer, N.},
title = {Object-Based Point Cloud Analysis of Full-Waveform Airborne Laser Scanning Data for Urban Vegetation Classification},
journal = {Sensors},
year = {2008},
volume = {8},
number = {8},
pages = {4505-4528},
doi = {http://dx.doi.org/10.3390/s8084505}
}
|
| Rutzinger, M., Höfle, B. & Korbinian, K. (2011), "Quality of geomorphological breaklines extracted from airborne laser scanning", In Geophysical Research Abstracts. Volume 13(EGU2011-8673) |
BibTeX:
@inproceedings{rutzinger_etal_2011_egu,
author = {Rutzinger, M. and Höfle, B. and Korbinian, K.},
title = {Quality of geomorphological breaklines extracted from airborne laser scanning},
booktitle = {Geophysical Research Abstracts},
year = {2011},
volume = {13},
number = {EGU2011-8673}
}
|
| Rutzinger, M., Höfle, B. & Pfeifer, N. (2008), "Object detection in airborne laser scanning data - an integrative approach on object-based image and point cloud analysis. In Object-based image analysis – spatial concepts for knowledge-driven remote sensing applications" Springer. |
| Abstract: In recent years object-based image analysis of digital elevation models acquired by airborne laser scanning gained in importance. Various applications for land cover classification (e.g. building and tree detection) already show promising results. Additionally to elevation rasters the original airborne laser scanning point cloud contains highly detailed 3D information. This paper introduces an integrative approach combining object-based image analysis and object-based point cloud analysis. This integrative concept is applied to building detection in the raster domain followed by a 3D roof facet delineation and classification in the point cloud. The building detection algorithm consists of a segmentation task, which is based on a fill sinks algorithm applied to the inverted digital surface model, and a rule-based classification task. The 340 buildings of the test site could be derived with 85% user’s accuracy and 92% producer’s accuracy. For each building object the original laser points are further investigated by a 3D segmentation (region growing) searching for planar roof patches. The finally delineated roof facets and their descriptive attributes (e.g. slope, 3D area) represent a useful input for a multitude of applications, such as positioning of solar-thermal panels and photovoltaics or snow load capacity modeling. |
BibTeX:
@inbook{rutzinger_etal_2008_springer,
author = {Rutzinger, M. and Höfle, B. and Pfeifer, N.},
title = {Object detection in airborne laser scanning data - an integrative approach on object-based image and point cloud analysis. In Object-based image analysis – spatial concepts for knowledge-driven remote sensing applications},
publisher = {Springer},
year = {2008}
}
|
| Rutzinger, M., Höfle, B. & Pfeifer, N. (2007), "Detection of high urban vegetation with airborne laser scanning data", In Proceedings forestsat 2007. Montpellier, France. November 2007., pp. digital media. |
| Abstract: Airborne laser scanning (ALS) is known as an operational tool for collecting high resolution elevation information (> 4 pt/m²). The characteristics of the emitted pulses, i.e. their spatial extent, allow the detection of multiple echoes, which occur especially in areas covered with high vegetation. In the case of forested areas this means that not only the first reflection on the canopy but also reflections on or near the ground surface are recorded. The detection of high vegetation in urban areas (single trees, groups, and small forests next to residential areas) is needed for several applications. Classified vegetation and derived parameters, such as height, volume and density, are used in urban planning, urban ecology and 3D city modeling. The here presented algorithm follows the principle of object-based point cloud analysis (OBPA), which consists of (i) segmentation of the original ALS point cloud, (ii) feature calculation for the delineated segments and (iii) classification to label the objects of interest. The segmentation is based on an intelligent seed point selection by surface roughness, initializing a region growing process. Point features for the segmentation and classification, respectively, are e.g. roughness, the ratio between 3D and 2D point density, or statistics on first an last echo occurrence within the segments. The advantage of the developed algorithm is that no calculation of a digital terrain model is needed and that it solely works in the original point cloud, maintaining the maximal achievable accuracy. For the evaluation of the method a flight campaign of the city of Innsbruck/Austria is used as test site. |
BibTeX:
@inproceedings{rutzinger_etal_2007_forestsat,
author = {Rutzinger, M. and Höfle, B. and Pfeifer, N.},
title = {Detection of high urban vegetation with airborne laser scanning data},
booktitle = {Proceedings forestsat 2007},
year = {2007},
pages = {digital media}
}
|
| Rutzinger, M., Höfle, B., Pfeifer, N., Geist, T. & Stötter, J. (2006), "Object-based analysis of airborne laser scanning data for natural hazard purposes using open source components", In International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. Salzburg, Austria. Volume 36(part 4/C42), pp. digital media. |
BibTeX:
@inproceedings{rutzinger_etal_2006_iaprs,
author = {Rutzinger, M. and Höfle, B. and Pfeifer, N. and Geist, T. and Stötter, J.},
title = {Object-based analysis of airborne laser scanning data for natural hazard purposes using open source components},
booktitle = {International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2006},
volume = {36},
number = {part 4/C42},
pages = {digital media}
}
|
| Rutzinger, M., Höfle, B., Vetter, M., Stötter, J. & Pfeifer, N. (2010), "Classification of breaklines derived from airborne LiDAR data for geomorphological activity mapping", In Geophysical Research Abstracts. Volume 12(EGU2010-2246-2) |
BibTeX:
@inproceedings{rutzinger_etal_2010a,
author = {Rutzinger, M. and Höfle, B. and Vetter, M. and Stötter, J. and Pfeifer, N.},
title = {Classification of breaklines derived from airborne LiDAR data for geomorphological activity mapping},
booktitle = {Geophysical Research Abstracts},
year = {2010},
volume = {12},
number = {EGU2010-2246-2}
}
|
| Rutzinger, M., Höfle, B., Oude Elberink, S. & Vosselman, G. (2011), "Feasibility of facade footprint extraction from mobile laser scanning data", Photogrammetrie, Fernerkundung, Geoinformation. Vol. 3, pp. 97-107. |
| Abstract: Terrestrial laser scanning provides valuable information for building outlining, facade detection and building reconstruction. Especially mobile laser scanning (MLS) is considered as well suited to collect 3D point clouds from building facades along road corridors for large areas. However, the completeness of facade representation in MLS has to be investigated in order to be able to draw conclusions about the usability of this kind of data sets for further applications such as building facade modelling. We investigate the detection rates of a fully automatic point cloud processing method for extracting building facades from MLS. The point cloud is segmented into planar regions, from which vertical structures are extracted. The detection rate is assessed by comparing the detected facade footprints with visible building outlines extracted from a digital cadastre map. The completeness of the extraction is investigated regarding the facade structure, length and the distance of the facades to the vehicle trajectory. It was found that the representation of facades extracted from MLS and the cadastral map might differ if very short facade parts (< 2 m) representing jutties are present on the ground level floor. This leads to an underestimation of completeness. Moreover, it can be shown that there is a direct relationship between further characteristics, e.g. that long facades and facades near to the vehicle are more likely to be detected than others. Facades with a length between 10 m and 20 m reach a completeness of 74%. Most facades are found in a distance of 10-20 m from the vehicle where the completeness ranges from 71% to 50%. The low completeness can be explained by occlusions from moving objects and vegetation, the facade structure, orientation and its complexity. The comparison with digital cadastral data shows that MLS is not that well suited for the detection of building facades as one might expect. |
BibTeX:
@article{rutzinger_etal_2011_pfg,
author = {Rutzinger, M. and Höfle, B. and Oude Elberink, S. and Vosselman, G.},
title = {Feasibility of facade footprint extraction from mobile laser scanning data},
journal = {Photogrammetrie, Fernerkundung, Geoinformation},
year = {2011},
volume = {3},
pages = {97-107},
doi = {http://dx.doi.org/10.1127/1432-8364/2011/0075}
}
|
| Rutzinger, M., Maukisch, M., Petrini-Monteferri, F. & Stötter, J. (2007), "Development of algorithms for the extraction of linear patterns lineaments from airborne laser scanning data", In Proceedings Geomorphology for the Future, Obergurgl. Obergurgl, Austria., pp. 161-168. Innsbruck University Press. |
| Abstract: The focus of this paper is the detection of surface discontinuities in laser scanning data. Lineaments represent linear surface structures like faults or fractures as well as geomorphologic features such as ridges or torrents. The detection and mapping of linear surface structures has high relevance in natural hazard assessment and spatial planning applications. In the surroundings of Innsbruck (Tyrol), lineaments were modelled by an algorithm especially developed for using laser scanning data. This algorithm detects areas with high surface curvature and linear slope discontinuities by applying geometric analysis and mathematical-statistical filters. The results are implemented into an information system for the management and analysis of laser scanning data. |
BibTeX:
@inproceedings{rutzinger_etal_2007_gfo,
author = {Rutzinger, M. and Maukisch, M. and Petrini-Monteferri, F. and Stötter, J.},
title = {Development of algorithms for the extraction of linear patterns lineaments from airborne laser scanning data},
booktitle = {Proceedings Geomorphology for the Future, Obergurgl},
publisher = {Innsbruck University Press},
year = {2007},
pages = {161-168}
}
|
| Rutzinger, M., Oude Elberink, S., Pu, S. & Vosselman, G. (2009), "Automatic extraction of vertical walls from mobile and airborne laser scanning data", In International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. Paris, France. September 2009. Volume 38(part 3/W8), pp. 7-11. |
| Abstract: Building outlines in cadastral maps are often created from different sources such as terrestrial surveying and photogrammetric analyses. In the latter case the position of the building wall cannot be estimated correctly if a roof overhang is present. This causes an inconsistent representation of the building outlines in cadastral map data. Laser scanning can be used to correct for such estimation inconsistencies and additional occurring changes in the building shape. Nowadays, airborne (ALS) and mobile laser scanning (MLS) data for overlapping areas are available. The object representation in ALS and MLS point clouds is rather different regarding point density, representation of object details (scale), and completeness, which is caused by the different platform position i.e. distance to the object and scan direction. These differences are analysed by developing a workflow for automatic extraction of vertical building walls from 3D laser scanning point clouds. A region growing segmentation using Hough transform derives the initial segments. These are then classified based on planarity, inclination, wall height and width. The planar position accuracy of corresponding walls and completeness of the automatically extracted vertical walls are investigated. If corresponding vertical wall segments are defined by a maximum distance of 0.1 m and maximum angle of 3º then 24 matches with a planimetric accuracy of 0.05 m RMS and 0.04 m standard deviation of the X- and Y-coordinates could be found. Finally the extracted walls are compared to building outlines of a cadastral map for map updating. The completeness of building walls in both ALS and MLS depends strongly on the relative position between sensor and object. A visibility analysis for the building façades is performed to estimate the potential completeness in the MLS data. Vertical walls in ALS data are represented as less detailed façades caused by lower point densities, which is enforced by large incidence angles. This can be compensated by the denser MLS data if the façade is covered by the survey. |
BibTeX:
@inproceedings{rutzinger_etal_2009_iaprs,
author = {Rutzinger, M. and Oude Elberink, S., and Pu, S. and Vosselman, G.},
title = {Automatic extraction of vertical walls from mobile and airborne laser scanning data},
booktitle = {International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2009},
volume = {38},
number = {part 3/W8},
pages = {7-11}
}
|
| Rutzinger, M., Pratihast, A., K., Oude Elberink, S. & Vosselman, G. (2010), "Detection and modelling of 3D trees from mobile laser scanning data", In International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Newcastle, United Kingdom. June 2010. Volume 38(part 5/ICWG V/I), pp. 520-525. |
| Abstract: Mobile laser scanning acquires massive point clouds in urban areas to provide high resolution data for 3D city modelling. A workflow for detecting and modelling trees from point clouds is presented. Emphasis lies on data reduction using an alpha shape approach. From the reduced point cloud the parameters are extracted to model the 3D trees using the Weber and Penn (1995) approach. The workflow is applied on two different sample data sets which were acquired with different mobile mapping systems and thus vary in quality and point density. The applied data reduction approach reduces the amount of data to process by about 95%. The tree models generated are consisting of a realistic trunk and branch structure of the tree crown. However, the inner branch structure of the tree crown is parameterised. Only the outer shape of the tree matches with the reality, which is sufficient for the requirements of visualization applications. For the tested areas the tree detection reaches a quality rate of 85% and 78% respectively. The comparison of the generated tree models against photographs and the original point cloud shows that the level of abstraction is sufficient for the integration of the tree models into 3D city models. |
BibTeX:
@inproceedings{rutzinger_etal_2010b,
author = {Rutzinger, M. and Pratihast, A., K. and Oude Elberink, S. and Vosselman, G.},
title = {Detection and modelling of 3D trees from mobile laser scanning data},
booktitle = {International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2010},
volume = {38},
number = {part 5/ICWG V/I},
pages = {520-525}
}
|
| Rutzinger, M., Pratihast, A., K., Oude Elberink, S. & Vosselman, G. (2011), "Tree modelling from mobile laser scanning datasets", The Photogrammetric Record. Vol. 26(134), pp. 1-12. |
| Abstract: In recent times mobile laser scanning (MLS) has been used to acquire massive 3D point clouds in urban areas and along road corridors for the collection of detailed data for 3D city modelling, building façade reconstruction and capture of vegetation and road features for inventories. The objectives of this paper are the extraction of tree features from such data-sets and the modelling of trees for the purpose of visualisation in 3D city models. After the detection of high vegetation the point cloud is reduced using a 3D alpha shape approach. Then the required model parameters such as crown and stem height, crown and stem diameter, and crown shape are derived and the trees are modelled individually in a realistic manner. The tree model so generated correctly represents the overall appearance of the tree. However, the inner structure such as the branching of the tree crown is parameterised. The workflow reduces the point cloud by means of a step-by-step process, which eases the handling of the massive MLS data-sets. The thinning using 3D alpha shapes reduces the amount of data to be processed by about 95%. It is shown that the model parameters are not influenced by the thinning procedure employed. This proves the robustness of the data reduction method and the tree modelling approach. |
BibTeX:
@article{rutzinger_etal_2011_pr,
author = {Rutzinger, M. and Pratihast, A., K. and Oude Elberink, S. and Vosselman, G.},
title = {Tree modelling from mobile laser scanning datasets},
journal = {The Photogrammetric Record},
year = {2011},
volume = {26},
number = {134},
pages = {1-12},
doi = {http://dx.doi.org/10.1111/j.1477-9730.2011.00635.x}
}
|
| Rutzinger, M., Rüf, B., Vetter, M. & Höfle, B. (2010), "Change detection of building footprints from airborne laser scanning acquired in short time intervals", In International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. Vienna, Austria. July 2010. Volume 38(part 7b), pp. 475-480. |
| Abstract: Several recent studies have shown that airborne laser scanning (ALS) of urban areas delivers valuable information for 3D city modelling and map updating. Building footprint detection from multi-temporal ALS lacks in comparability because of changing ALS flight parameters, flying season, interpolation settings if digital elevation models are used, and the ability of the used building detection method to deal with these influences. So far, less attention has been paid to change detection of buildings within a short time span (approx. three months), where major problems are the high variability of vegetation over time and to distinguish temporary objects from small changes of buildings, which are currently under construction and demolition, respectively. We introduce an object-based workflow to investigate how unchanged objects can be defined, which variability in the object appearance is allowed to define an object as unchanged, and at which threshold a change can be indicated. The test site is situated in the city of Innsbruck (Austria) where ALS data is available from summer and autumn in 2005. In an initial step building footprints are derived by an object-based image analysis (OBIA) detection method for each flight independently. The parameters for building detection are derived for a training site in order to automatically derive the rules of the classification tree. Then the object features of buildings derived from the different flights are compared to each other and separated into the classes unchanged building, new building, demolished building, new building part, and demolished building part. The results are verified by a reference, which was created manually by visual inspection of the elevation difference image of both epochs. For new buildings and building parts 90% and for demolished buildings and building parts 32% were detected correctly. The detection of demolished buildings is strongly influenced by the appearance of high vegetation, which is caused by the decreasing heights of trees by comparing summer (leaf-on) and autumn (leaf-off) ALS data. |
BibTeX:
@inproceedings{rutzinger_etal_2010c,
author = {Rutzinger, M. and Rüf, B. and Vetter, M. and Höfle, B.},
title = {Change detection of building footprints from airborne laser scanning acquired in short time intervals},
booktitle = {International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences},
year = {2010},
volume = {38},
number = {part 7b},
pages = {475-480}
}
|
| Rutzinger, M., Rottensteiner, F. & Pfeifer, N. (2009), "A comparison of evaluation techniques for building extraction from airborne laser scanning", IEEE journal of selected topics in applied earth observation and remote sensing. Vol. 2(1), pp. 11-20. |
| Abstract: In this paper, different methods for the evaluation of building detection algorithms are compared. Whereas pixel-based evaluation gives estimates of the area that is correctly classified, the results are distorted by errors at the building outlines. These distortions are potentially in an order of 30%. Object-based evaluation techniques are less affected by such errors. However, the performance metrics thus delivered are sometimes considered to be less objective, because the definition of a ldquocorrect detectionrdquo is not unique. Based on a critical review of existing performance metrics, selected methods for the evaluation of building detection results are presented. These methods are used to evaluate the results of two different building detection algorithms in two test sites. A comparison of the evaluation techniques shows that they highlight different properties of the building detection results. As a consequence, a comprehensive evaluation strategy involving quality metrics derived by different methods is proposed. |
BibTeX:
@article{rutzinger_etal_2009_jstar,
author = {Rutzinger, M. and Rottensteiner, F. and Pfeifer, N.},
title = {A comparison of evaluation techniques for building extraction from airborne laser scanning},
journal = {IEEE journal of selected topics in applied earth observation and remote sensing},
year = {2009},
volume = {2},
number = {1},
pages = {11-20},
doi = {http://dx.doi.org/10.1109/JSTARS.2009.2012488}
}
|
| Sailer, R., Bollmann, E., Hoinkes, S., Rieg, L., Stötter, J. & Sproß, M. (), "Quantification of geomorphodynamic processes in glaciated and recently deglaciated terrain based on airborne laser scanning data", Geografiska Annaler, Series A - Physical Geography. (submitted) |
BibTeX:
@article{Sailer,
author = {Rudolfs Sailer and Erik Bollmann and Susanna Hoinkes and Lorenzo Rieg and Johann Stötter and Maximilian Sproß},
title = {Quantification of geomorphodynamic processes in glaciated and recently deglaciated terrain based on airborne laser scanning data},
journal = {Geografiska Annaler, Series A - Physical Geography},
number = {submitted}
}
|
| Sailer, R., Fellin, W., Fromm, R., Jörg, P., Rammer, L., Sampl, P. & Schaffhauser, A. (2008), "Snow avalanche mass-balance calculation and simulation-model verification", Annals of Glaciology., June, 2008. Vol. 48, pp. 183-192. |
| Abstract: Two- or three-dimensional avalanche-simulation models offer a wide range of applications; however, a challenging model-verification process is demanded, accompanied by a reliable determination of model-input parameters. We show that a verification process can be arranged with remote-monitoring data from an artificially triggered avalanche, leading to the calculation of avalanche mass balance. Two numerical methods are applied to increase the quality of the parameter fit and to reduce the number of simulations. The quality of the parameter fit is verified by comparing measured and simulated run-out lengths. In addition, a cross-check is performed using velocities derived from Doppler radar measurements. |
BibTeX:
@article{Sailer2008a,
author = {Rudolf Sailer and Wolfgang Fellin and Reinhard Fromm and Philipp Jörg and Lambert Rammer and Peter Sampl and Andreas Schaffhauser},
title = {Snow avalanche mass-balance calculation and simulation-model verification},
journal = {Annals of Glaciology},
year = {2008},
volume = {48},
pages = {183--192},
url = {http://www.ingentaconnect.com/content/igsoc/agl/2008/00000048/00000001/art00025},
doi = {http://dx.doi.org/10.3189/172756408784700707}
}
|
| Sailer, R., Fromm, R., Jörg, P., Schaffhauser, A. & Adams, M. (2008), "Ground Based Remote Sensing of Snow Properties and Avalanche Simulation", Proceedings of Earch Conference 2008, Lesbos, Greece. |
BibTeX:
@article{Sailer2008,
author = {R. Sailer and R. Fromm and P. Jörg and A. Schaffhauser and Marc Adams},
title = {Ground Based Remote Sensing of Snow Properties and Avalanche Simulation},
journal = {Proceedings of Earch Conference 2008, Lesbos, Greece},
year = {2008}
}
|
| Sailer, R., Höfle, B., Bollman, E., Vetter, M., Stötter, J., Pfeifer, N., R.M. & Geist, T. (2009), "Multitemporal error analysis of LiDAR data for geomorphological feature detection", In Geophysical Research Abstracts. Vienna, Austria. Volume 11(EGU2009-4799-2) |
BibTeX:
@inproceedings{sailer_etal_egu,
author = {Sailer, R. and Höfle, B. and Bollman, E. and Vetter, M. and Stötter, J. and Pfeifer, N., Rutzinger, M. and Geist, T.},
title = {Multitemporal error analysis of LiDAR data for geomorphological feature detection},
booktitle = {Geophysical Research Abstracts},
year = {2009},
volume = {11},
number = {EGU2009-4799-2}
}
|
| Schaffhauser, A., Adams, M., Fromm, R., Jörg, P., Luzi, G., Noferini, L. & Sailer, R. (2008), "Remote sensing based retrieval of snow cover properties", Cold Regions Science and Technology., November, 2008. Vol. 54(3), pp. 164-175. |
| Abstract: In order to overcome the restrictions of conventional observation methods, novel remote monitoring techniques such as terrestrial laser scanning (TLS) and ground based interferometric synthetic aperture radar (GB SAR) are concurrently operated. Snow depth and snow water equivalent (SWE) or the snow mass on ground are some of the key parameters in the assessment of avalanche hazard, for snow, snow drift and avalanche modelling as well as model verification. While the TLS provides maps of the spatial snow depth distribution, the GB SAR can in principle be used to retrieve snow depth and SWE. Remote sensing results are compared to traditional field work, additionally advantages and limitations of the techniques are identified. Finally, the applicability of the remote sensing based retrieval of these snow cover properties for snow and snow avalanche applications is summarized. |
BibTeX:
@article{Schaffhauser2008,
author = {A. Schaffhauser and M. Adams and R. Fromm and P. Jörg and G. Luzi and L. Noferini and R. Sailer},
title = {Remote sensing based retrieval of snow cover properties},
journal = {Cold Regions Science and Technology},
year = {2008},
volume = {54},
number = {3},
pages = {164--175},
url = {http://www.sciencedirect.com/science/article/B6V86-4T4HP21-1/2/f764a3c462438b79718ffa4d973f0e22},
doi = {http://dx.doi.org/10.1016/j.coldregions.2008.07.007}
}
|
| Vetter, M., Höfle, B., Mandelburger, G. & Rutzinger, M. (2011), "Estimating changes of riverine landscapes and riverbeds by using airborne LiDAR data and river cross-sections", Annals of Geomorphology. , pp. accepted. |
| Abstract: Today, Airborne Laser Scanning (ALS), also referred to as airborne LiDAR, derived Digital Terrain Models (DTMs) and Digital Surface Models (DSMs) are used in different scientific disciplines, such as hydrology, geomorphology, forestry, archaeology and others. In geomorphology, ALS data are used for studies on landslides, soil erosion, mass movements, glacial geomorphology, river geomorphology, and many others. In the field of river geomorphology, ALS data sets provide information on riverine vegetation, the water level and water-land-boundaries, the elevation of the riparian foreland and their roughness. Small-footprint ALS systems used for topographic data acquisition operate mainly in the near-infrared wavelength. Thus, topographic ALS is not able to penetrate water but to provide a highly detailed representation of the dry land. Therefore, a method to derive Digital Bathymetric Models (DBMs) by using river cross-sections acquired by terrestrial field surveys is presented in this paper. The DBM, which is combined with the ALS-DTM to a DTM of the watercourse, is the basis for calculating changes of the riverbed and the riverine landscape between two ALS data epochs. The first step of the DBM delineation method is to separate water from land in the ALS data. A raster-based approach to derive the Water-Extent-Polygon (WEP) is presented which incorporates the signal strength of the ALS backscatter (referred to as intensity or amplitude), terrain slope and height differences between the DTM and DSM (i.e. the so-called normalized DSM, nDSM). In the second step, the river centerline is extracted by applying a shrinking algorithm to the WEP. Subsequently, a dense array of 2D-transects, perpendicular to the centerline, is defined. For these 2D-transects the heights are interpolated linearly from the measured river cross-sections. From the obtained 3D point cloud representing the riverbed a raster model can be calculated by applying a suitable interpolation technique. In the final step, the DTM and the DBM are combined to a DTM of the watercourse. For two available ALS-DTM data sets (years 2003 and 2006) the respective watercourse DTMs are calculated based on terrestrial measured river cross-section data sets. By computing difference-models changes in the water level between the two ALS-DTMs are calculated. To estimate the accumulation and erosion potential of the riverbed between the two periods, the difference-model of watercourse DTMs is used. The results show the potential of using ALS in combination with river cross-section data as input for DBM modeling, watercourse DTM generation, riverine landscape and riverbed change detection. The main objectives of the paper are on presenting an accurate WEP delineation approach and a workflow to model a watercourse DTM. |
BibTeX:
@article{vetter_etal_2011,
author = {Vetter, M. and Höfle, B. and Mandelburger, G. and Rutzinger, M.},
title = {Estimating changes of riverine landscapes and riverbeds by using airborne LiDAR data and river cross-sections},
journal = {Annals of Geomorphology},
year = {2011},
pages = {accepted}
}
|
| Vetter, M., Höfle, B., Mandlburger, G. & Rutzinger, M. (2008), "Ableitung von Flusssohlenmodellen aus Flussquerprofilen und Integration in Airborne Laserscanning Geländemodelle mit GRASS GIS", In Angewandte Geoinformatik 2008, Beiträge zum 20. AGIT-Symbosium Salzburg AGIT Symposium und Fachmesse Angewandte Geoinformatik. Salzburg, Austria. July 2008., pp. 382-391. |
BibTeX:
@inproceedings{vetter_etal_2008_agit,
author = {Vetter, M. and Höfle, B. and Mandlburger, G. and Rutzinger, M.},
title = {Ableitung von Flusssohlenmodellen aus Flussquerprofilen und Integration in Airborne Laserscanning Geländemodelle mit GRASS GIS},
booktitle = {Angewandte Geoinformatik 2008, Beiträge zum 20. AGIT-Symbosium Salzburg AGIT Symposium und Fachmesse Angewandte Geoinformatik},
year = {2008},
pages = {382-391}
}
|
| Vetter, M., Höfle, B., Mandlburger, G. & Rutzinger, M. (2010), "Change detection of riverbed movements using river cross-sections and LiDAR data", In Geophysical Research Abstracts. Volume 12(EGU2010-8169) |
BibTeX:
@inproceedings{vetter_etal_2010,
author = {Vetter, M. and Höfle, B. and Mandlburger, G. and Rutzinger, M.},
title = {Change detection of riverbed movements using river cross-sections and LiDAR data},
booktitle = {Geophysical Research Abstracts},
year = {2010},
volume = {12},
number = {EGU2010-8169}
}
|
| Vetter, M., Höfle, B., Pfeifer, N., Rutzinger, M. & Stötter, J. (2009), "On the use of airborne LiDAR for braided river monitoring and water surface delineation", In Geophysical Research Abstract. Vienna, Austria. April 2009. Volume 11(EGU2009-7524-2) |
BibTeX:
@inproceedings{vetter_etal_2009_egu2,
author = {Vetter, M. and Höfle, B. and Pfeifer, N. and Rutzinger, M. and Stötter, J.},
title = {On the use of airborne LiDAR for braided river monitoring and water surface delineation},
booktitle = {Geophysical Research Abstract},
year = {2009},
volume = {11},
number = {EGU2009-7524-2}
}
|
| Vetter, M., Höfle, B. & Rutzinger, M. (2009), "Water classification using 3D airborne laser scanning point clouds", Österreichische Zeitschrift für Vermessung und Geoinformation (VGI). Vol. 2, pp. 227-238. |
| Abstract: Airborne laser scanning (ALS), also referred to as airborne LiDAR (Light Detection And Ranging), provides highly accurate measurements of the Earth surface. In the last twenty years, ALS data has been established as a standard technique for delineating objects (e.g. buildings, trees, roads) and mapping changes. Studies on hydrology or geomorphology such as monitoring of braided river structures, calculation of erosion and accumulation potential in watercourses, or floodplain mapping all require the precise location of the water surface. This paper shows a 3D point cloud based method, which allows an automatic water surface classification by using geometric and radiometric ALS information and the location of modeled lost reflections, which are called laser shot dropouts. The classification result can be used to map the watercourse, improve DTM filtering routines or replace water points with river bed heights for hydraulic modeling etc. The method relies on a threshold based classification using geometry as well as radiometric information of the 3D point cloud. The method is divided into five major steps. First, we correct the amplitude values by reducing the atmospheric and geometric influences to the laser shots. A radiometric adjustment was applied to the amplitude values of the data sets, which allows a multi-temporal analysis of the amplitude values. The second step is the interpretation of the coordinates of the laser shot dropouts, which are the most important input to delineate water surfaces. In step three and four the two attributes (standard deviation of the height and the amplitude density ratio value) are calculated at a fixed distance to each reflection and dropout. These are used in step five to distinguish water and dry land points. The exploration of the attributes for the classification and the evaluation of the classification results are done by comparing them to a terrestrial orthophoto mosaic, which was taken simultaneously to the ALS campaign. One of the major tasks is the use of modeled laser shot dropouts within the threshold based classification method for distinguishing water and non-water echoes. The method is also suited to detect water under riverine vegetation, which is problematic by using data from sensors, which are not able to penetrate vegetation. The classification accuracy is about 95%. The amplitude correction and the radiometric adjustment makes the data sets comparable and allows to calculate changes in the channel flow paths over the different flights. |
BibTeX:
@article{vetter_etal_2009_vgi,
author = {Vetter, M. and Höfle, B. and Rutzinger, M.},
title = {Water classification using 3D airborne laser scanning point clouds},
journal = {Österreichische Zeitschrift für Vermessung und Geoinformation (VGI)},
year = {2009},
volume = {2},
pages = {227-238}
}
|
| Vetter, M., Hoefle, B., Pfeifer, N., Rutzinger, M., Sailer, R., Stötter, J. & Geist, T. (2009), "The Hintereisferner - eight years of experience in method development for glacier monitoring with airborne LiDAR", In Geophysical Research Abstracts. Vienna, Austria. April 2009. Volume 11(EGU2009-7405-3) |
BibTeX:
@inproceedings{vetter_etal_2009_egu1,
author = {Vetter, M. and Hoefle, B. and Pfeifer, N. and Rutzinger, M. and Sailer, R. and Stötter, J. and Geist, T.},
title = {The Hintereisferner - eight years of experience in method development for glacier monitoring with airborne LiDAR},
booktitle = {Geophysical Research Abstracts},
year = {2009},
volume = {11},
number = {EGU2009-7405-3}
}
|
| Wichmann, V., Rutzinger, M. & Vetter, M. (2008), "Digital terrain model generation from airborne laser scanning point data and the effect of grid-cell size on the simulation results of a debris flow model", In Hamburger Beiträge zur Physischen Geographie und Landschaftsökologie. Institut für Geographie der Universität Hamburg. Volume 19, pp. 103-113. |
| Abstract: Airborne laser scanning technology allows a rapid and cost-effective measurement of topography at high spatial resolutions over large areas. In this paper we present the generation of digital terrain models (DTMs) with different grid-cell sizes from a classified point cloud including several postprocessing steps such as morphological filtering and surface depression filling. A qualitative analysis is carried out to investigate the effect of grid-cell size on the simulation results of a debris flow model. Like most of the available debris flow models for natural hazard assessment, this model was originally developed for application on regional scales. So far, only few studies address possible consequences arising out of the application of such models on high-resolution DTMs. The results of this study suggest, that the debris flow model is only applicable at a certain range of scales and that flow path routing algorithms, not taking into account the local flow depth, have to be used with care on DTMs, which preserve a high level of topographic detail. |
BibTeX:
@inproceedings{wichmann_etal_2008_hbpgl,
author = {Wichmann, V. and Rutzinger, M. and Vetter, M.},
title = {Digital terrain model generation from airborne laser scanning point data and the effect of grid-cell size on the simulation results of a debris flow model},
booktitle = {Hamburger Beiträge zur Physischen Geographie und Landschaftsökologie},
year = {2008},
volume = {19},
pages = {103-113}
}
|
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