Project structure and responsibilities
The research project Alpine Hydro Airborne Mapping (AAHM) focuses primarily on the research areas 1) data acquisition, 2) data processing and data management and 3) data evaluation (see figure below). The research areas are executed under the responsibility of a scientific project partners, partially with the support of the industrial project partners.
In the following, the scientific project partners are presented briefly as well as the planned results of the three research areas.
Unit of Hydraulic Engineering, Department of Infrastructure (Link)
The Unit of Hydraulic Engineering is the initiator and consortium leader and of AAHM. The Unit is primarily responsible for the execution of the research area 3, "Data Evaluation". Here, Prof. Dr. Markus Aufleger is research area leader as well as the project coordinator for the overall project.
Research Area 3, the data evaluation, is concerned with the application of laser data within the hydrological context of alpine river systems. An emphasis is placed on the use of high-resolution, digital terrain models for the numerical modelling of hydraulic and sediment transport-related processes. The AAHM data will allow a better understanding of dynamic processes, such as sediment transport and the development of fluvial structures in alpine gravel rivers. Furthermore, the rivers can be judged regarding their hazard potential in the case of floods and bed load relocations can be quantified with the multi-temporal aerial survey of the same river reach.
Additionally, the AAHM data are used to examine ecological aspects of pre-alpine to alpine rivers and delta systems. The classification of river reaches in the categories “river bed”, “vegetation” and where appropriate “anthropogenic structures”, together with the measured underwater geometries of the rivers allows an assessment of water-related habitats.
Another aspect is the water power-related assessment of rivers and reservoirs. Aggradations in the inlet structures of turbines and water deviation systems cause lower efficiency of power plants and hydraulic measures. These sediment bodies can be detected with AAHM data and, if necessary, removed. High input of sediments in reservoirs leads to the loss of storage capacity. The intersection of AAHM laser data with echo sounder data enables high-resolution measurement of the underwater geometry of reservoirs in alpine areas to great depths.
Department of Geodesy and Geoinformation, Vienna University of Technology (Link)
The Vienna University of Technology (TUW), Department for Geodesy and Geoinformation, research group Photogrammetry is responsible for the area "Data processing and Data Management" (Key Researcher: Prof. Dr. Norbert Pfeifer, Area Manager: Dr. Gottfried Mandlburger). The overall aim of this project area is the establishment of data processing and management facilities in the form of efficient methods and software tools, as well as comprehensive data analysis to understand and exploit the full potential of the captured data.
Processing of topo-bathymetric data raises additional research problems compared to traditional topographic laser scanning. These are: (i) the green laser signal gets reflected and refracted at the air-water-interface and the propagation speed is lower in water than in the atmosphere, (ii) the complex scattering of the laser beam in water poses additional problems for a reliable detection and description of distinct laser echoes, (iii) different types of water echoes (floor of water body, volume backscatter and water surface) need to be distinguished when classifying the point cloud, (iv) signal absorption within the water column needs to be taken into account for the radiometric calibration of the laser echoes, and (v) measuring in the two different media (water/air) poses additional questions for sensor orientation and geometric calibration. Solving these problems from a theoretical point of view as well as providing concrete algorithms, comprising best-practice processing work flows, and implementations of software components are the contribution of TUW within the AAHM-R2P project.
Unit of Surveying and Geoinformation, University of Innsbruck (Link)
The Unit of Surveying and Geoinformation, University of Innsbruck, is the scientific leader of the research area 1, "Data Acquisition". This includes both, the measurement with the bathymetric, airborne LIDAR system as well as all terrestrial and sonar measurements for subaquatic ground detection.
In addition, the team of Univ. Prof. Dr. Klaus Hanke and Dr. Thomas Weinold is responsible for terrestrial control measurements and the thoroughly evaluation of the LIDAR data from the research area 2, data processing and data management. Furthermore, in selected test areas, the surveying accuracy is verified, as well as the completeness of the recorded data.