UAV platforms are nowadays a valuable source of data for inspection, surveillance, mapping and 3D modeling issues. New applications in the short- and close-range domain are introduced, being the UAVs a low-cost alternatives to the classical manned a erial photogrammetry. Rotary or fixed wing UAVs, capable of performing the photogrammetric data acquisition with amateur or SLR digital cameras, can fly in manual, semi-automated and autonomous modes. With a typical photogrammetric pipeline, 3D results like DSM/DTM, contour lines, textured 3D models, vector data, etc. can be produced, in a reasonable automated way. The paper reports the latest developments of UAV image processing methods for photogrammetric applications, mapping and 3D modeling issues. Automation is nowadays necessary and feasible at the image orientation, DSM generation and orthophoto production stages, while accurate feature extraction is still an interactive procedure. New perspectives are also addressed.

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Uav photogrammetry for mapping and 3d modeling - current status and future perspectives -

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Permafrost and climate in Europe: Monitoring and modelling thermal, geomorphological and geotechnical responses

This review paper examines thermal conditions (active layer and permafrost), internal composition (rock and ice components), kinematics and rheology of creeping perennially frozen slopes in cold mountain areas. The aim is to assemble current information about creep in permafrost and rock glaciers from diverse published sources into a single paper that will be useful in studies of the flow and deformation of subsurface ice and their surface manifestations not only on Earth, but also on Mars. Emphasis is placed on quantitative information from drilling, borehole measurements, geophysical soundings, photogrammetry, laboratory experiments, etc. It is evident that quantitative holistic treatment of permafrost creep and rock glaciers requires consideration of: (a) rock weathering, snow avalanches and rockfall, with grain-size sorting on scree slopes; (b) freezing processes and ice formation in scree at sub-zero temperatures containing abundant fine material as well as coarse-grained blocks; (c) coupled thermohydro-mechanical aspects of creep and failure processes in frozen rock debris; (d) kinematics of non-isotropic, heterogeneous and layered, ice-rich permafrost on slopes with long transport paths for coarse surface material from the headwall to the front and, in some cases, subsequent re-incorporation into an advancing rock glacier causing corresponding age inversion at

Permafrost creep and rock glacier dynamics

https://www.uibk.ac.at/geographie/personal/kerschner/larstig-qsr.pdf

Latest Pleistocene and Holocene glacier variations in the European Alps

. The mountain cryosphere of mainland Europe is recognized to have important impacts on a range of environmental processes. In this paper, we provide an overview on the current knowledge on snow, glacier, and permafrost processes, as well as their past, current, and future evolution. We additionally provide an assessment of current cryosphere research in Europe and point to the different domains requiring further research. Emphasis is given to our understanding of climate–cryosphere interactions, cryosphere controls on physical and biological mountain systems, and related impacts. By the end of the century, Europe's mountain cryosphere will have changed to an extent that will impact the landscape, the hydrological regimes, the water resources, and the infrastructure. The impacts will not remain confined to the mountain area but also affect the downstream lowlands, entailing a wide range of socioeconomical consequences. European mountains will have a completely different visual appearance, in which low- and mid-range-altitude glaciers will have disappeared and even large valley glaciers will have experienced significant retreat and mass loss. Due to increased air temperatures and related shifts from solid to liquid precipitation, seasonal snow lines will be found at much higher altitudes, and the snow season will be much shorter than today. These changes in snow and ice melt will cause a shift in the timing of discharge maxima, as well as a transition of runoff regimes from glacial to nival and from nival to pluvial. This will entail significant impacts on the seasonality of high-altitude water availability, with consequences for water storage and management in reservoirs for drinking water, irrigation, and hydropower production. Whereas an upward shift of the tree line and expansion of vegetation can be expected into current periglacial areas, the disappearance of permafrost at lower altitudes and its warming at higher elevations will likely result in mass movements and process chains beyond historical experience. Future cryospheric research has the responsibility not only to foster awareness of these expected changes and to develop targeted strategies to precisely quantify their magnitude and rate of occurrence but also to help in the development of approaches to adapt to these changes and to mitigate their consequences. Major joint efforts are required in the domain of cryospheric monitoring, which will require coordination in terms of data availability and quality. In particular, we recognize the quantification of high-altitude precipitation as a key source of uncertainty in projections of future changes. Improvements in numerical modeling and a better understanding of process chains affecting high-altitude mass movements are the two further fields that – in our view – future cryospheric research should focus on.

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The European mountain cryosphere: a review of its current state, trends, and future challenges

This paper presents a special method of measuring surface deformation and flow velocity of creeping rock glaciers based on digital photogrammetry. The underlying concept of automatic measurement of 3-D surface displacement vectors in time-series of multi-year digital aerial photographs is explained. In contrast to standard photogrammetric procedures, image matching is not carried out in the space of the original photos but in quasi-orthophotos derived from the use of rough and preliminary digital terrain models. A software package called ADVM (Automatic Displacement Vector Measurement), written in Visual C for running on a Windowsbased PC, has been developed. The software has been tested within the framework of two case studies which comprise the spatio-temporal analysis of the kinematic behavior of three active rock glaciers in the Austrian Alps. The adjacent Inneres and Aeusseres Hochebenkar rock glaciers in the Oetztal Alps and the Hinteres Langtalkar rock glacier located in the Schober group, Hohe Tauern range, are investigated. Selected results of the photogrammetric evaluation are presented numerically and graphically. Permafrost, Phillips, Springman & Arenson (eds) © 2003 Swets & Zeitlinger, Lisse, ISBN 90 5809 582 7

Quantitative analysis of rock glacier creep by means of digital photogrammetry using multi-temporal aerial photographs: two case studies in the Austrian Alps

The detection and quantification of surface deformation of an active rock glacier using the differential synthetic aperture radar (SAR) interferometry (D-InSAR) technique is presented. An average deformation rate of -6 mm/35 days in the radar line of ight was estimated for the summer of 1992. The maximum deformation rate, -18 mm/35 days, was identified at the upper part of the rock glacier, whereas the deformation rate at the snout of the rock glacier was about -10 mm/35 days. The spatial distribution of the surface deformation in the D-InSAR displacement map is smooth and supports the idea that ice is the stress-transferring medium in rock glaciers.

Estimation of rock glacier surface deformation using SAR interferometry data

We argue that the future of remote sensing will see a diversification of sensors and sensor platforms. We argue further that remote sensing will also benefit from recent advances in computing technology to employ new algorithms previously too complex to apply. In this paper we support this argument by three demonstrations. First, we show that an unmanned aerial vehicle (UAV) equipped with digital cameras can provide valuable visual information about the Earth’s surface rapidly and at low cost from nearly any viewpoint. Second, we demonstrate an end-to-end workflow to process a sizeable block of such imagery in a fully automated manner. Thirdly, we build this workflow on a novel computing system taking advantage of the invention of the Graphics Processing Unit (GPU) that is capable of performing complex algorithms in an acceptable elapsed time. The transition to diverse imaging sensors and platforms results in a requirement to deal with unordered sets of images, such as typically collected from a UAV, and to match and orientate these images automatically. Our approach is fully automated and capable of addressing large datasets in reasonable time and at low costs on a standard desktop PC. We compare our method to a semi-automatic orientation approach based on the PhotoModeler software and demonstrate superior performance in terms of automation, accuracy and processing time.

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Viktor Kaufmann

Papers

Permafrost creep and rock glacier dynamics

Quantitative analysis of rock glacier creep by means of digital photogrammetry using multi-temporal aerial photographs: two case studies in the Austrian Alps

Estimation of rock glacier surface deformation using SAR interferometry data

Towards fully automatic photogrammetric reconstruction using digital images taken from uavs

Rock glacier dynamics: implications from high-resolution measurements of surface velocity fields