Philipp Glira

• PhD
• Researcher at Austrian Institute of Technology

Airborne LiDAR (Light Detection And Ranging) and airborne photogrammetry are both proven and widely used techniques for the 3D topographic mapping of extended areas. Although both techniques are based on different reconstruction principles (polar measurement vs. ray triangulation), they ultimately serve the same purpose, the 3D reconstruction of th...

Recent developments in the field of rail vehicles increased the demand for accurate and up-to-date 3D maps of rail track networks. Collision avoidance systems, semi-automated, or fully autonomous rail vehicles strongly benefit from such high quality maps. In this work, we present a fully automatic, photogrammetric method for the 3D reconstruction o...

Airborne Laser Scanning (ALS) is an efficient method for the acquisition of dense and accurate point clouds over extended areas. To ensure a gapless coverage of the area, point clouds are collected strip wise with a considerable overlap. The redundant information contained in these overlap areas can be used, together with ground-truth data, to re-c...

In order to minimize discrepancies within the overlap area of airborne laser scanning (ALS) strips, strip adjustment can be performed. Apart from the transformation model, the quality of strip adjustment is strongly affected by the observations used in this process. In order to exploit the full resolution of the data, correspondences should be esta...

Several advancements are going with Unmanned Aerial Systems (UAS) with the addition of multiple sensors and simultaneous data acquisition to obtain detailed geo-data for various applications. However, simultaneous data acquisition with multiple sensors, namely camera, and LiDAR, will also result in possible discrepancies associated with them, and t...

Nonrigid registration presents a significant challenge in the domain of point cloud processing. The general objective is to model complex nonrigid deformations between two or more overlapping point clouds. Applications are diverse and span multiple research fields, including registration of topographic data, scene flow estimation, and dynamic shape...

Non-rigid registration presents a significant challenge in the domain of point cloud processing. The general objective is to model complex non-rigid deformations between two or more overlapping point clouds. Applications are diverse and span multiple research fields, including registration of topographic data, scene flow estimation, and dynamic sha...

Mobile robotic applications need precise information about the geometric position of the individual sensors on the platform. This information is given by the extrinsic calibration parameters which define how the sensor is rotated and translated with respect to a fixed reference coordinate system. Erroneous calibration parameters have a negative imp...

Rapid Mapping • UAV • Disaster Response • Densification • Stereo reconstruction using GPU • Fully georeferenced dense cloud • Surface Generation • 2.5D elevation grid map • Orthorectification

UAVs have become an indispensable tool for a variety of mapping applications. Not only in the area of surveying, infrastructure planning and environmental monitoring tasks but also in time-critical applications, such as emergency and disaster response. Although UAVs enable rapid data acquisition per se, data processing usually relies on offline wor...

This paper presents a study on the potential of ultra-high accurate UAV-based 3D data capture by combining both imagery and LiDAR data. Our work is motivated by a project aiming at the monitoring of subsidence in an area of mixed use. Thus, it covers built-up regions in a village with a ship lock as the main object of interest as well as regions of...

Environmental perception is one of the core requirements in autonomous vehicle navigation. If exposed to harsh conditions, commonly deployed sensors like cameras or lidars deliver poor sensing performance. Millimeter wave radars enable robust sensing of the environment, but suffer from specular reflections and large beamwidths. To incorporate the s...

This chapter presents the sediment budget of the Upper Kaunertal (Kauner valley, Ötztal Alps, Austria) for the years 2012–2014 as obtained in the framework of the PROSA (high-resolution measurements of morphodynamics in rapidly changing PROglacial Systems of the Alps) research project. An important methodological basis of this high-mountain sedimen...

Diameter at breast height (DBH) is one of the most important parameter in forestry. With increasing use of terrestrial and airborne laser scanning in forestry, new exceeding possibilities to directly derive DBH emerge. In particular, high resolution point clouds from laser scanners on board unmanned aerial systems (UAS) are becoming available over...

Modern airborne sensors integrate laser scanners and digital cameras for capturing topographic data at high spatial resolution. The capability of penetrating vegetation through small openings in the foliage and the high ranging precision in the cm range have made airborne LiDAR the prime terrain acquisition technique. In the recent years dense imag...

Recent developments in satellite altimetry are leading to improved spatial resolution, allowing applications in the coastal zone and over inland waters. Validation of these sensors near the shore remains a challenge, since the process of upscaling from single point measurements (gauges or GPS buoys) to the radar altimetry footprint is a source of u...

Laserscanning ist eine polare Messmethode, die Daten flächenhaft aufnimmt und auswertet, also eine „polare Photogrammetrie“. Laserscanning liefert Punktwolken für die Modellierung unserer Umgebung, z. B. die topographische Situation oder Kulturgüter. Die aktive Messmethode einschließlich der Laser-Bathymetrie zur Flussgrundvermessung werden beschri...

A new generation of laser scanners mounted on Unmanned Aerial Vehicles ( UAVs ) have the potential to provide high- quality point clouds of comparatively small areas (a few hectares). The high maneuverability of the UAVs , a typically large field of view of the laser scanners, and a comparatively small measurement range lead to point clouds with ve...

The protected fossil oyster reef in Stetten, Austria is the world's largest excavated fossil oyster reef, formed by large sea shells. About 50.000 up to 60-cm-long shells cover a 459 m2 large area. The reef consists primarily of Crassostrea gryphoides shells. In this study, our motivation is to reconstruct the original shell positions with automati...

This study analyses the underestimation of tree and shrub heights for different airborne laser scanner systems and point cloud distribution within the vegetation column. Reference data was produced by a novel UAV-borne laser scanning (ULS) with a high point density in the complete vegetation column. With its physical parameters (e.g. footprint) and...

This study analyses the underestimation of tree and shrub heights for different airborne laser scanner systems and point cloud distribution within the vegetation column. Reference data was produced by a novel UAV-borne laser scanning (ULS) with a high point density in the complete vegetation column. With its physical parameters (e.g. footprint) and...

Laserscanning ist eine polare Messmethode, die Daten flächenhaft aufnimmt und auswertet, also eine „polare Photogrammetrie“. Laserscanning liefert Punktwolken für die Modellierung unserer Umgebung, z. B. die topographische Situation oder Kulturgüter. Die aktive Messmethode einschließlich der Laser-Bathymetrie zur Flussgrundvermessung werden beschri...

Highlights: Very high point density UAS-based laser scanner point clouds of an alluvial forest acquired with the RIEGL VUX-SYS were analyzed w.r.t. forestry applications. With point densities >1500 points/m² and accuracies <2 cm the study shows that individual stems and branches, understory, lying deadwood, and the terrain are clearly represented i...

In this paper we report on a flight experiment employing airborne laser bathymetry (ALB) and unmanned aerial vehicle (UAV) based laser scanning (ULS) for capturing very high resolution topography of shallow water areas and the surrounding littoral zone at the pre-alpine Pielach River in Austria. The aim of the research is to assess how information...

In this article the principle of laser scanning is recapitulated starting from the LiDAR equation and the measurement possibilities, especially beyond the range measurement, are explained. This includes the radiometric measurement, bathymetric LiDAR, waveform capturing, new possibilities from UAV platforms, and single photon counting detection. It...

The development of lightweight, survey-grade Lidar sensors has made it possible to equip unmanned aerial systems (UASs) with very precise laser scanners, thus opening up new possibilities in the domain of close-range 3D mapping. To test the capabilities of UAS-borne laser scanning, a flight experiment was conducted using the RIEGL VUX full-waveform...

When it comes to transport capacity, debris flows are among the most efficient processes in high mountain areas. In addition, they constitute an important process for a coupling of slope and channel systems. If the contribution of episodic processes to the sediment budget of a catchment is to be quantified, the magnitude-frequency relationship of d...

Terrestrial laser scanning can provide high-resolution, two-dimensional sampling of soil surface roughness. While previous studies demonstrated the usefulness of these roughness measurements in geophysical applications, questions about the number of required scans and their resolution were not investigated thoroughly. Here, we suggest a method to g...

Muren zählen hinsichtlich ihrer Transportleistung zu den geomorphologisch wirksamsten Prozessen im Hochgebirge. Darüber hinaus stellen sie oft einen bedeutenden Prozess zur Kopplung von Hang- und Gerinnesystemen dar. Um den Beitrag dieser episodischen Prozesse zum Sedimenthaushalt eines Einzugsgebietes zu quantifizieren, muss die Magnitude-Frequenz...

The actual on-going and predicted climate change leads in sensitive areas like in high-mountain proglacial regions to significant geomorphodynamic processes (e.g. landslides). Within a short time period (even less than a year) these processes lead to a substantial change of the landscape. In order to study and analyse the recent changes in a progla...

Glacier melt and a consequential increased sediment transport (erosion, transportation and accumulation) in high mountain regions are causing a frequent occurrence of geomorphic processes such as landslides and other natural hazards. These effects are investigated at the Gepatschferner (Kaunertal, Oetztal Alps, Tyrol), the second largest glacier in...

For the georeferencing of point clouds acquired by a terrestrial laser scanner (TLS) targets with known coordinates (control points) can be used. The determination of the target positions in a global coordinate frame with a total station and/or with GNSS can be very time-consuming. For multi-temporal comparison of TLS data these targets can be perm...

Unmanned aerial vehicles (UAV) are a promising platform for close range airborne photogrammetry. Next to the possibility of carrying certain sensor equipment, different on board navigation components may be integrated. These devices are getting, due to recent developments in the field of electronics, smaller and smaller and are easily affordable. T...