Magnus Bremer

Magnus Bremer
Austrian Academy of Sciences (OeAW) | ÖAW · Institute for Interdisciplinary Mountain Research

PhD

About

48
Publications
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589
Citations

Publications

Publications (48)
Article
Full-text available
Point clouds derived from UAV-borne laser scanning and UAV-borne photogrammetry provide new opportunities for 3D topographic monitoring in geographic research. The airborne acquisition strategy overcomes common challenges of ground-based techniques, such as limited spatial coverage or heterogeneous measurement distribution, and allows flexible repe...
Article
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Land Surface Temperature (LST) products from thermal infrared imaging rely on information about the spatial distribution of Land Surface Emissivity (LSE). For portable, broadband thermal cameras for drone- or ground-based measurements with camera to object distances up to a few kilometres and with meter-scale resolution, threshold-based retrieval o...
Chapter
Fernerkundungsdaten finden in zahlreichen Forschungsfeldern der Geographie Verwendung. In den letzten Jahrzehnten sind für den gesamten Globus flächendeckende zeiträumliche Datenarchive in unterschiedlichen Maßstäben entstanden, die ein digitales Labor darstellen und verschiedenste, auch in der Zeit zurückblickende Analysen, ermöglichen. Der Ableit...
Article
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New geospatial technologies and ubiquitous sensing allow new insights into people’s spatial practices and experiences of public spaces. These tools offer new data streams for analysis and interpretation of social phenomena. Mobile augmented reality tools such as smartphones and wearables merge the experience of entangled online and offline spaces i...
Article
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Optical satellite imagery with high temporal and spatial resolution, such as acquired by Sentinel-2, is increasingly becoming available and is used to derive maps of tree species. Such mapping products are required in the scope of operational and sustainable forest management. Existing studies that employ Sentinel-2 imagery have already evaluated d...
Article
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The 3rd edition of the international summer school “Close-range Sensing Techniques in Alpine terrain” took place in Obergurgl, Austria, in June 2019. This article reports on results from the training and seminar activities and the outcome of student questionnaire survey. Comparison between the recent edition and the past edition in 2017 shows no si...
Article
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Unmanned aerial vehicle laser scanning (ULS) has recently become available for operational mapping and monitoring (e.g. for forestry applications or erosion studies). It combines advantages of terrestrial and airborne laser scanning, but there is still little proof of ULS accuracy. For the detection and monitoring of small-magnitude surfaces change...
Article
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In complex mountainous terrain the mapping efficiency is a crucial factor. Unmanned aerial vehicle (UAV) based laser scanning (ULS) has the capability for efficient mapping, as it allows realizing higher flight velocities, higher flying altitude above ground level (AGL) and larger distances between neighbouring flight strips, compared to image base...
Article
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Slow moving deep-seated gravitational slope deformations are threatening infrastructure and economic wellbeing in mountainous areas. Accelerating landslides may end up in a catastrophic slope failure in terms of rapid rock avalanches. Continuous landslide monitoring enables the identification of critical acceleration thresholds, which are required...
Article
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Multi-temporal 3D point clouds acquired with a laser scanner can be efficiently used for an area-wide assessment of landslide-induced surface changes. In the present study, displacements of the Vögelsberg landslide (Tyrol, Austria) are assessed based on available data acquired with airborne laser scanning (ALS) in 2013 and data acquired with an unm...
Article
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With this contribution we assess the potential of unmanned aerial vehicle (UAV) based laser scanning for monitoring shallow erosion in Alpine grassland. A 3D point cloud has been acquired by unmanned aerial vehicle laser scanning (ULS) at a test site in the subalpine/alpine elevation zone of the Dolomites (South Tyrol, Italy). To assess its accurac...
Article
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Im Zuge der voranschreitenden Digitalisierung und der damit verbundenen steigenden Verfügbarkeit von digitalen Daten gewinnen geografische Informationssysteme zur Analyse und Verwaltung von Geodaten in vielen technisch-wissenschaftlichen Bereichen, einschließlich der Siedlungswasserwirtschaft, immer mehr an Bedeutung. Rund 90 % der weltweit verfügb...
Article
Full-text available
Deep-seated gravitational slope deformations (DSGSDs) endanger settlements and infrastructure in mountain areas all over the world. To prevent disastrous events, their activity needs to be continuously monitored. In this paper, the movement of the Reissenschuh DSGSD in the Schmirn valley (Tyrol, Austria) is quantified based on point clouds acquired...
Article
Recent improvements in topographic LiDAR technology allow the detailed characterization of individual trees at both branch and leaf scale, providing more accurate information to support phenological and ecological research. However, an effective methodology to map single leaves in 3-D is still missing. This letter presents a point cloud segmentatio...
Article
Full-text available
The 2nd international summer school “Close-range sensing techniques in Alpine terrain” was held in July 2017 in Obergurgl, Austria. Participants were trained in selected close-range sensing methods, such as photogrammetry, laser scanning and thermography. The program included keynotes, lectures and hands-on assignments combining field project plann...
Article
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Abstract The investigation of changes in spatial patterns of vegetation and identification of potential micro-refugia requires detailed topographic and terrain information. However, mapping alpine topography at very detailed scales is challenging due to limited accessibility of sites. Close-range sensing by photogrammetric dense matching approaches...
Article
Fine-scale architectural tree models serve as an effective representation of three-dimensional plant material distributions. They can help to quantify wood volume and biomass, to estimate leaf area distributions on a detailed scale, and can be exploited for physically based modelling approaches. If architectural tree models can be derived for multi...
Article
Terrestrial laser scanning (TLS) is often used to monitor landslides and other gravitational mass movements with high levels of geometric detail and accuracy. However, unstructured TLS point clouds lack semantic information, which is required to geomorphologically interpret the measured changes. Extracting meaningful objects in a complex and dynami...
Conference Paper
Full-text available
Light Detection and Ranging (LiDAR) especially the ground based LiDAR (Terrestrial Laser Scanning-TLS) is an operational used and widely available measurement tool supporting forest inventory updating and research in forest ecology. High resolution point clouds from TLS already represent single leaves which can be used for a more precise estimation...
Article
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Canopy density measures such as the Leaf Area Index (LAI) have become standardized mapping products derived from airborne and terrestrial Light Detection And Ranging (aLiDAR and tLiDAR, respectively) data. A specific application of LiDAR point clouds is their integration into radiative transfer models (RTM) of varying complexity. Using, e.g., ray t...
Conference Paper
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Shallow landslides are gravitational mass movements of unconsolidated material on hillslopes with a maximum depth of about two meters. These dynamic processes are usually triggered by hydro-meteorological events, such as heavy rainfall events or rapid snowmelt. Shallow landslides affect infrastructure, cause a loss of soil and degrade agricultural...
Article
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Collecting comprehensive knowledge about spectral signals in areas composed by complex structured objects is a challenging task in remote sensing. In the case of vegetation, shadow effects on reflectance are especially difficult to determine. This work analyzes a larch forest stand (Larix decidua MILL.) in Pinnis Valley (Tyrol, Austria). The main g...
Article
Full-text available
Collecting comprehensive knowledge about spectral signals in areas composed by complex structured objects is a challenging task in remote sensing. In the case of vegetation, shadow effects on reflectance are especially difficult to determine. This work analyzes a larch forest stand ( Larix decidua MILL.) in Pinnis Valley (Tyrol, Austria). The main...
Article
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In the Alps as well as in other mountain regions steep grassland is frequently affected by shallow erosion. Often small landslides or snow movements displace the vegetation together with soil and/or unconsolidated material. This results in bare earth surface patches within the grass covered slope. Close-range and remote sensing techniques are promi...
Article
Full-text available
In the Alps as well as in other mountain regions steep grassland is frequently affected by shallow erosion. Often small landslides or snow movements displace the vegetation together with soil and/or unconsolidated material. This results in bare earth surface patches within the grass covered slope. Close-range and remote sensing techniques are promi...
Conference Paper
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Recently multispectral LiDAR became a promising research field for enhanced LiDAR classification workflows and e.g. the assessment of vegetation health. Current analyses on multispectral LiDAR are mainly based on experimental setups, which are often limited transferable to operational tasks. In late 2014 Optech Inc. announced the first commercially...
Article
Information on geometries and kinematics of landslides are necessary to establish geological slope deformation models. We present two complementary geospatial methods to analyze landslide surface changes even in areas affected by strong surface pattern changes, making use of airborne laser scanning (ALS) data. An image correlation method based on s...
Conference Paper
Full-text available
The mapping of road environments is an important task, providing important input data for a broad range of scientific disciplines. Pole-like objects, their visibility and their influence onto local light and traffic noise conditions are of particular interest for traffic safety, public health and ecological issues. Detailed knowledge can support th...
Article
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The architecture of trees is of particular interest for 3D model creation in forestry and ecolocical applications. Terrestrial (TLS) and mobile laser scanning (MLS) systems are used to acquire detailed geometrical data of trees. Since 3D point clouds from laser scanning consist of large data amounts representing uninterpreted topographical informat...
Conference Paper
Full-text available
Recently, terrestrial laser scanning (TLS) and matching of images acquired by unmanned arial vehicles (UAV) are operationally used for 3D geodata acquisition in Geoscience applications. However, the two systems cover different application domains in terms of acquisition conditions and data properties i.e. accuracy and line of sight. In this study w...
Conference Paper
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Change detection of dynamic surface elements is an important application in geomorphological analysis. In order to be able to investigate such changes, the high spatial resolution and accuracy of the laser scanning technology is exploited. Dealing with laser scanning data, most change detection approaches are aiming at the assessment of volumetric...
Article
As rockfall can cause a great deal of damage, it is essential to know its spatial propagation. Rockfall models are sensitive to the resolution of input data, i.e. the Digital Terrain Model (DTM) used. Nowadays, high resolution elevation data are available area-wide from airborne laser scanning (ALS). However, rockfall models are designed for analys...
Conference Paper
Full-text available
Erosion by shallow landslides is a widespread and growing phenomenon in mountainous areas. The major consequences are loss of soil and regolith as well as damages on infrastructure and provision of unconsolidated material for secondary processes such as mudflows. In this study we present a concept for extracting morphometry parameters from terrestr...
Article
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In summer 2007 at the "Bliggspitze" (Eastern Alps, 3453 m.a.s.l.), rock and ice fall events testify to increasing slope activities. At the northern slope of the summit a 400 m by 200 m glacier-covered rock mass slab initiated to move downward. The movement causes strong fragmentation of the glacier and the paragneisic rock mass. This process is doc...
Article
Sass, O., Haas, F., Schimmer, C., Heel, M., Bremer, M., Stöger, F. and Wetzel, K.-F. 2012. Impact of forest fires on geomorphic processes in the Tyrolean Limestone Alps. Geografiska Annaler: Series A, Physical Geography, 94, 117–133. doi:10.1111/j.1468-0459.2012.00452.x We investigated geomorphic processes on two slopes (Arnspitze and Bettelwurf) b...
Article
We quantified the sediment volume transported by a major debris flow event in the Halltal, Austrian Alps, using a combination of terrestrial (TLS) and airborne laser scanning (ALS) which has rarely been carried out before. A digital terrain model (DTM) derived from ALS data (pre-event surface) was combined with a DTM derived from TLS data (post-eve...
Conference Paper
Full-text available
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...
Conference Paper
Full-text available
Country-wide ALS datasets of high resolution become more and more available and can provide a solid basis for geomorphological research. On the other hand, terrain changes after geomorphological extreme events can be quickly and flexibly documented by TLS and be compared to the pre-existing ALS datasets. For quantifying net-erosion, net-sedimentati...

Projects

Projects (4)
Project
Innsbruck Summer School of Alpine Research - Close Range Sensing Techniques in Alpine Terrain https://www.uibk.ac.at/geographie/summerschool/2022/
Project
[http://4dlamb.mountainresearch.at/]
Archived project
The aim of the project 4D-FORMAT is to develop an area-wide applicable mapping product for forest soil moisture conditions considering species compositions. The mapping products will combine microwave remote sensing data (Sentinel-1) with multispectral data (Sentinel-2) and will additionally integrate high resolution digital surface models from airborne laser scanning and photogrammetry in order to define homogeneous forest topographic units for multi-temporal analysis. The latter will allow an innovative object based analysis on homogeneous forest units addressing the forest structure and topography in relation to moisture and species composition. [ http://4dformat.mountainresearch.at/ ]