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Copyright of Geodetski Vestnik is the property of Sveza Geodetov Slovenije and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

True orthophoto is a better product than a classical orthophoto in urban areas, because buildings are depicted in the correct plane position, and the content around the building is also visible. The main goal of our research was to verify two approaches of a true orthophoto production: a) true orthophoto production based on digital terrain model and digital building model, and b) automatic true orthophoto production. We performed the research in two test areas within the Municipality of Ljubljana. We compared the both procedures and the produced true orthophotos with the classical orthophoto, and assessed the production time component as well. To produce true orthophoto, larger overlapping of aerial images is required, thus the time for aerial surveying is increased by approximately 25 percentage. The time of work, compared to classical orthophoto production, is lower by the factor 0.75 for automatically produced true orthophoto, and is greater by the factor 2.3 for the true orthophoto based on digital terrain model and digital building model. Aesthetic appearance of automatically produced orthophoto has only minor shortcomings on the buildings’ roof edges which are slightly serrated. Considering all the mentioned aspects, the automatically produced true orthophoto is competitive with the classical orthophoto. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles, equipped with various sensors and devices, are increasingly used to acquire geospatial data in geodesy, geoinformatics, and environmental studies. In this context, a new research and professional field has been developed – UAV photogrammetry – dealing with photogrammetry data acquisition and data processing, acquired by unmanned aerial vehicles. In this study, we analyse the selected factors that impact the quality of data provided using UAV photogrammetry, with the focus on positional accuracy; they are discussed in three groups: (a) factors related to the camera properties and the quality of images; (b) factors related to the mission planning and execution; and (c) factors related to the indirect geo referencing of images using ground control points. These selected factors are analysed based on the detailed review of relevant scientific publications. Additionally, the influence of the number of ground control points and their spatial distribution on point clouds' positional accuracy has been investigated for the case study. As the conclusion, key findings and recommendations for UAV photogrammetric projects are given; we have highlighted the importance of suitable lighting and weather conditions when performing UAV missions for spatial data acquisition, quality equipment, appropriate parameters of UAV data acquisition, and a sufficient number of ground control points, which should be determined with the appropriate positional accuracy and their correct distribution in the field. [ABSTRACT FROM AUTHOR]

Copyright of Geodetski Vestnik is the property of Sveza Geodetov Slovenije and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geodetski Vestnik is the property of Sveza Geodetov Slovenije and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geodetski Vestnik is the property of Sveza Geodetov Slovenije and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The results of our research are presented in which we tested the hypothesis that the quality (especially positional accuracy and semantic quality) of national orthophoto of the same territory in different time periods has being improved as a consequence of more quality input data. A review of orthophoto production and the methods of quality assessment in the observed time frame (1994-2012) are presented. Four orthophoto map sheets have been selected for the analysis, that were produced in 4 to 6 different years and where we can find also high relief. A great number of check points between 29 in 42) has been selected in each orthophoto map sheet, which were measured in the field and orthophoto. For each map sheet and the year we calculated a root mean square error (RMSE) from discrepancies between the field and orthophoto coordinates, we also produced tables and graphs. Numerical and graphical analyses of the results clearly show the trend of decreasing RMSE value from the older to the newer orthophoto issues, thus we can confirm our hypothesis. Planimetric accuracy, assessed with the RMSE value, has been significantly improved in the observed period roughly from 1.4 m to 0.4 m), which proves a positive impact of technological and other changes on the national orthophoto quality. [ABSTRACT FROM AUTHOR]

Copyright of Geodetski Vestnik is the property of Sveza Geodetov Slovenije and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geodetski Vestnik is the property of Sveza Geodetov Slovenije and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

When ordering LiDAR data, LiDAR point density per surface unit is important information with decisive influence on the price of the LiDAR survey. The paper first deals with the theoretical calculation of the minimum LiDAR point density, necessary for the acquisition of topographic data of the largest scales. For this purpose the sampling theorem is used. However, since topographic objects (roads, water bodies, etc.) and phenomena represented on topographic maps and in topographic bases are in many cases located under vegetation, also the rate of laser beam penetration through vegetation for the area where the topographic data are to be gathered has to be known. In a research on a test case conducted in the area of the town Nova Gorica we calculated the rate of laser beam penetration for four different vegetation types: scarce Mediterranean vegetation, thick thermophilic deciduous forest, mixed vegetation (meadows, orchards and forest) and built-up area. By connecting the theoretic minimum LiDAR point density with the rate of penetration, we defined the minimum LiDAR point density for the needs of data acquisition on topographic maps of the largest scales or in topographic bases of comparable detail (from 1 : 1000 to 1 : 10,000). [ABSTRACT FROM AUTHOR]

Copyright of Geodetski Vestnik is the property of Sveza Geodetov Slovenije and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The relatively rapid changes of the shape and volume of glaciers that have been recorded in the last few decades can be monitored and recorded in different ways. Photogrammetry, the science of obtaining metrical data about the environment from photographs, is especially appropriate for this task. Modern photogrammetric methods enable solutions for complex tasks such as the reconstruction of the spatial position of a glacier in previous time periods from non-technical (amateur, archive, etc.) photographs. A simpler way is to photograph a glacier with special photogrammetric cameras that have a known and stable construction. In the case study of Triglav glacier, a photogrammetric team coped with a major professional challenge: how to reconstruct the three-dimensional shape and surface of the glacier from archive photographs. These photographs have been taken regularly almost every month from two fixed standpoints over many years with a simple non-metrical Horizont camera. The solution of this task initially required the calibration of the Horizont camera to establish the geometrical features of the photographs. In addition, a helicopter survey and a terrestrial survey of the glacier using a stereo-technique were done during a major interdisciplinary expedition in September 1999. The archive photographs were linked to the new metrical photographs through selected tie points. Additionally, photographs from the cyclical aerial survey were used. Existing computer programs had to be augmented, and several new programs had to be developed since standard photogrammetric methods were not sufficient to solve the problem The final aim of this part of the project was the determination of a surface model of the glacier in different time sequences and the computation of the volume differences in different time sequences. Experts from other sciences could use these results for various studies, e. g., estimating correlations between climate changes and the shrinkage of the... [ABSTRACT FROM AUTHOR]

The article discusses the highlights of the second Summer School (SS) on laser scanning which was organized by the WG VI/5: Promotion of the Profession to Students and the Student Consortium (SC) and held in Ljubljana, Slovenia from July 1-7, 2007. The event, which was aimed at providing an intensive and educational week with training activities for students and young researchers, was hosted by the Faculty of Civil and Geodetic Engineering, University of Ljubljana. An overview of lecture sessions held at the university is presented.