When studying the development of different geomorphic processes, floods, glaciers or even cultural heritage through time, one cannot rely only on regular photogrammetrical procedures and metrical images. In a majority of cases the only available images are the archive images with unknown parameters of interior orientation showing the object of interest in oblique view. With the help of modern high resolution digital elevation models derived from aerial or terrestrial laser scanning (lidar) or from photogrammetric stereo-images by automatic image-matching techniques even single nonmetric high or low oblique image from the past can be applied in the monoplotting procedure to enable 3D-data extraction of changes through time. The first step of the monoplotting procedure is the orientation of an image in the space by the help of digital elevation model (DEM). When using oblique images tie points between an image and DEM are usually too sparse to enable automatic exterior orientation, still the manual interactive orientation using common features can resolve such shortages. The manual interactive orientation can be very time consuming. Therefore, before the start of the manual interactive orientation one should be certain if one can expect useful results from the chosen image. But how to decide which image has the highest mapping potential before we introduce a certain oblique image in orientation procedure? The test examples presented in this paper enable guidance for the use of monoplotting method for different geoscience applications. The most important factors are the resolution of digital elevation model (the best are the lidar derived ones), the presence of appropriate common features and the incidence angle of the oblique images (low oblique images or almost vertical aerial images are better). First the very oblique example of riverbank erosion on Dragonja river, Slovenija, is presented. Than the test example of September 2010 floods on Ljubljana moor is discussed. Finally, case study from November 2012 floods is presented. During November 2012 floods an initiative was launched to gather as much non-metrical images of floods as possible from casual observers (volunteered image gathering). From all gathered images the guidelines presented before helped to pick out 21 % images which were used for monoplotting.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 37331245In this doctoral dissertation, a new algorithm is proposed for the estimation of photovoltaic and wind potential over large area, which is represented with a topological grid structure that is constructed from high-resolution laser-scanned LiDAR data. At first, the position of the Sun relative to the geographic location is calculated, as well as shadowing and anisotropic irradiance, by considering multiannual measurements of direct and diffuse irradiance. Calculated instantaneous global irradiance is integrated with respect to time using the global irradiance-dependent nonlinear efficiency characteristics of a given photovoltaic system. In the second part of the dissertation, a new methodology is presented for the estimation of wind potential over the constructed topological grid, in which the computer simulation of wind flow represented as clusters of air molecules is performed by using the Lagrangian method of smoothed particle hydrodynamics and Reynolds averaged turbulence model. In order to implement the estimation of wind flow, multiannual meteorological measurements of the wind velocity and direction are also considered, which are then used for constructing logarithmic wind profile that defines the initial conditions of the wind particles. In order to calculate the output power the nonlinear characteristics of wind systems are used, which depend on the calculated wind velocities. The calculated power values can then be integrated with respect to time in order to forecast electrical energy production. Both methodologies are merged into the proposed algorithm, which we implement on a graphics processing unit using CUDA technology, in order to perform the calculations in an acceptable time. Within the experimental part of the doctoral thesis, the accuracy of the calculation based on the input data is evaluated by comparing the calculated values with independent measurements. The proposed algorithm was also applied over the large geographical area of Maribor, in order to estimate its photovoltaic and wind potentials. The estimated photovoltaic potential has an agreement of 97%, while the agreement of the estimated wind potential is 92%.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 285053696The achievements of the project have got an important impact also in the broad publicity. Namely, our algorithm for buildings recognition has been evaluated as the best algorithm in its category at the competition organised by the International Society for Photogrammetry and Remote Sensing. This success has gained a large attraction in Slovene media. We would like to stress very popular weekly public voting on the most popular Slovene radio station VAL 202, where our researcher Domen Mongus was convincingly elected for the personality of the week.
F.18 Transfer of new know-how to direct users (seminars, fora, conferences)
COBISS.SI-ID: 18425622gLiDAR software tool has been designed for object recognition in the LiDAR data, and supports creation of digital terrain models (DTM) and the classification of captured points into terrain, buildings and vegetation classes. In this way, gLiDAR achieves the essential steps in the preparation of content for geographic information systems and geospatial analysis of large geographical areas with extremely high accuracy. gLiDAR has been used for processing of the LiDAR data for the whole Republic of Slovenia.
F.06 Development of a new product
COBISS.SI-ID: 19366166Airborne laser scanning of Slovenia will for the first time allow the analysis of Slovenia's surface at high resolution, with height accuracy of LiDAR generated DTM 1 m × 1 m below 15 cm (RMSE) and postural error below 30 cm (RMSE). This is a significant improvement in comparison to the previously existing photogrammetric DTM 5 m × 5 m, with height accuracy of 1 m (RMSE) in the open field and 3 m (RMSE) in overgrown field. The article presents products of laser scanning of Slovenia as well as the quality control of products. Latter shall be obtained on the basis of laser scans with a density of 5 points / m2 or for critical areas and of 2 points / m2 for forested areas. The derived products include classified point-clouds, the terrain, DMR 1 m × 1 m, and the image of analytical shading of DMR at 1m resolution. In the paper, we also describe the possibilities and potentials of these products to study the surface and built-up areas in Slovenia.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 18646806