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Traditional measurement methods are still widely used for recording cultural heritage objects. On the other hand, geodetic surveying and modern technologies such as 3D laser scanning can provide more accurate, geometrically consistent and extremely detailed data that can be used as a basis for detailed vector maps or 3D models. The main aim of our research was to investigate the complementary approach, using both traditional and modern methods, in order to produce detailed vector maps of the Romanesque church of St. Martin in Chapaize, France, which are essential for further unveiling its historic development. Geometrically, this church is rather extensive and has many irregularities in its shape. Our approach to the documentation process is presented and evaluated in this paper. We applied the Procrustes analysis for the ground floor map, which gave us an objective accuracy assessment. Point clouds of the bell tower acquired by two different laser instruments have also been compared.

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 manual work, compared to classical orthophoto production, is lower by the factor 0.27 for automatically produced true orthophoto, and is greater by the factor 2.75 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.

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 georeferencing 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.

Most cadastral systems today are coordinate-based and contain only a weak or no reference to measurements or the origin of the information. In some contexts, this is largely due to the transition of land data management and maintenance from an analogue to a digital environment. This study focuses on analysing the importance of the measurement-based cadastre and the digitisation process in North Macedonia and Slovenia. The survey-based boundary data and their integration into the digital environment were not considered in either case study. The positional differences between the survey-based boundary coordinates and the graphical coordinates of the boundaries are significant. The RMSE(2D) for Trebosh was 48 cm, and the RMSE(2D) for Ivanjševci was 56 cm. Consequently, the differences in location affected the areas of the cadastral parcels, resulting in an RMSE of 26 m2 and 23 m2 for Trebosh and Ivanjševci, respectively. These differences can be considered as differences within the cadastral boundary data. Therefore, before harmonising the data between the cadastre and the land register, the inconsistencies within the cadastral data should be eliminated first. The differences in the location of cadastral boundaries and parcel area create new challenges in cadastral procedures (formatting of parcels), conflicts in the relocation of boundaries, and impacts on the land market. The solution lies in the way data is maintained, avoiding duplication of attributes or eliminating inconsistencies (after duplication). Both solutions require further modifications of the legal framework for cadastral procedures related to boundary adjustments and data compliance. This study provides a basis for evaluating inconsistencies in cadastral data and highlights the importance of proper source data selection in the digitization process.

Aerial laser scanning provides information about the reflectivity of the surface from which the laser beam was reflected; this information is given as an intensity of a laser point. By comparing the average non-normalised intensity values for different tree species growing in Slovenia in laser scanning data sets acquired with different wavelengths, whether tree species can be separated based only on laser scanning intensity data was investigated. We studied 113 single trees (57 coniferous and 56 deciduous trees), identified in the field and in four laser data sets. The first two were acquired in the 1550 nm wavelength: the first set in spring (May 15, 2012), the second in late summer (September 18, 2012). The last two sets were acquired in the 1064 nm wavelength: the third in winter (March 5, 2013) and the fourth in summer (July 7, 2014). Among other things, we have determined, the same as researchers before us: (i) that the average intensities of deciduous trees in both wavelengths are higher in the leaf-on season, while it is the opposite in the leaf-off season; (ii) that the average intensities of the combined class of first and the only reflections is higher than the average intensities of all reflections in leaf-on season; during the leaf-off season it is the opposite. The behavior of tree species Juglans regia, Acer Pseudoplatanus, Fraxinus excelsior and Tilia cordata (or Tilia Platyphylolos) also implies that the differences in the average intensities in laser time series enable the determination of the phenological phase of deciduous trees in the spring.

The topic of this paper is the challenges of using remote sensing technologies as one of the potential data sources for the establishment of a 3D real property cadastre in Slovenia. More than a decade ago, the legal basis for the registration of property rights on the buildings and parts of buildings was provided in Slovenia, and for this purpose, the Building Cadastre was established. The analyses of the current data within the Land Cadastre and the Building Cadastre revealed that the 3D graphical representation of buildings, where the second level of detail (LoD 2) was discussed, requires additional data in which significant roof points should be additionally acquired. For this purpose, i.e. the creation of a graphical 3D-model of a building at the level LoD 2, we use the cadastral and national topographic data that covers the entire state territory, which are stereopairs of aerial photographs of the cyclic aerial survey (CAS) and airborne laser scanning data. Using a case study, we have analysed and discussed the appropriateness of the state airborne laser scanning data as an additional data source, along with the current cadastral data, for the creation of 3D-building model at the second level of detail, which is important from the cadastral as well as topographic perspective.

This paper provides the innovative approach of using a spatial extract, transform, load (ETL) solution for 3D building modelling, based on an unmanned aerial vehicle (UAV) photogrammetric point cloud. The main objective of the paper is to present the holistic workflow for 3D building modelling, emphasising the benefits of using spatial ETL solutions for this purpose. Namely, despite the increasing demands for 3D city models and their geospatial applications, the generation of 3D city models is still challenging in the geospatial domain. Advanced geospatial technologies provide various possibilities for the mass acquisition of geospatial data that is further used for 3D city modelling, but there is a huge difference in the cost and quality of input data. While aerial photogrammetry and airborne laser scanning involve high costs, UAV photogrammetry has brought new opportunities, including for small and medium-sized companies, by providing a more flexible and low-cost source of spatial data for 3D modelling. In our data-driven approach, we use a spatial ETL solution to reconstruct a 3D building model from a dense image matching point cloud which was obtained beforehand from UAV imagery. The results are 3D building models in a semantic vector format consistent with the OGC CityGML standard, Level of Detail 2 (LOD2). The approach has been tested on selected buildings in a simple semi-urban area. We conclude that spatial ETL solutions can be efficiently used for 3D building modelling from UAV data, where the data process model developed allows the developer to easily control and manipulate each processing step.

In this article, a method for the automatic detection of power lines in a horizontal xy plane from airborne and terrestrial laser scanning data is presented. The workflow is composed of four main steps: pre-processing with classification of a point cloud, filtering of the point cloud, the detection of points on the power lines by applying the Hough transform (HT), and vectorisation of power line locations and their intersections. In the pre-processing step, most of the points that are not representing power lines are eliminated via classification of the point cloud. We present our filter, which reduces the number of points in the point cloud further and thus accelerates data processing and increases the reliability of processing in the next steps. We detect the points on the power lines with the HT on the vector points in the xy plane. The final track of the power lines is derived from the straight segments computed by the method of the least squares from the points that HT recognised on the power lines. The results are assessed visually and via relative comparison of the computed intersections coordinates with the reference data manually extracted from the filtered point cloud. The proposed method detects almost all power lines in the test area for both data sets.

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.

A point cloud is the result of laser scanning; in the case of terrestrial laser scanning, the point cloud is composed of points scanned from one or more positions. To register these points into one point cloud, so-called tie points are needed; these may be object points (natural targets) or selected stabilized targets (artificial targets). Spherical targets are often used as artificial targets; these must have their centre coordinates and radius determined. The centre coordinates of a sphere are calculated on the basis of scanned points on the spheres’ surface. This paper presents two procedures for determining the best reflection region on the sphere to determine its parameters, and the procedure for determining the optimal distance between the scanner and sphere.The best reflection area on the sphere is determined in two ways. The first is based on minimizing the difference between sphere radii when, in the adjustment process, the radius of the sphere is treated as a known and unknown quantity. The second is based on the standard deviation of the sphere’s centre coordinates at the independent determinations of sphere parameters from randomly chosen scanned points on the sphere surface. For each of the spheres, the best ratio between the laser beam footprint area and the target surface area is calculated for the optimal combination of scanning distance and region. For the best combination of scanning distance and region, we chose the one with the smallest standard deviation of the sphere centre coordinates.

The main goal of our research was to design and implement an innovative target that would be suitable for accurately registering point clouds produced from unmanned aerial vehicle (UAV) images and terrestrial laser scans. Our new target is composed of three perpendicular planes that combine the properties of plane and volume targets. The new target enables the precise determination of reference target points in aerial and terrestrial point clouds. Different types of commonly used plane and volume targets as well as the new target were placed in an established test area in order to evaluate their performance. The targets were scanned from multiple scanner stations and surveyed with an unmanned aerial vehicle DJI Phantom 4 PRO at three different altitudes (20, 40, and 75 m). The reference data were measured with a Leica Nova MS50 MultiStation. Several registrations were performed, each time with a different target. The quality of these registrations was assessed on the check points. The results showed that the new target yielded the best results in all cases, which confirmed our initial expectations. The proposed new target is innovative and not difficult to create and use.

In order to transcend the challenge of accelerating the establishment of cadastres and to efficiently maintain them once established, innovative, and automated cadastral mapping techniques are needed. The focus of the research is on the use of high-resolution optical sensors on unmanned aerial vehicle (UAV) platforms. More specifically, this study investigates the potential of UAV-based cadastral mapping, where the ENVI feature extraction (FX) module has been used for data processing. The paper describes the workflow, which encompasses image pre-processing, automatic extraction of visible boundaries on the UAV imagery, and data post-processing. It shows that this approach should be applied when the UAV orthoimage is resampled to a larger ground sample distance (GSD). In addition, the findings show that it is important to filter the extracted boundary maps to improve the results. The results of the accuracy assessment showed that almost 80% of the extracted visible boundaries were correct. Based on the automatic extraction method, the proposed workflow has the potential to accelerate and facilitate the creation of cadastral maps, especially for developing countries. In developed countries, the extracted visible boundaries might be used for the revision of existing cadastral maps. However, in both cases, the extracted visible boundaries must be validated by landowners and other beneficiaries.

Topografski podatki, kot pomemben del Nacionalne prostorske podatkovne infrastrukture, so bili v letih po osamosvojitvi Slovenije deležni velike pozornosti, postali so splošno dostopni, bili so dopolnjeni in medsebojno usklajeni. V zadnjem desetletju pa se je vlaganje v topografske podatke v Sloveniji zelo omejilo, zato danes nikakor več ne moremo biti zadovoljni z njihovim stanjem. V prispevku pregledno predstavljamo stanje topografskih podatkov v Sloveniji, analiziramo njihovo kakovost in ustreznost za potencialne in dejanske uporabnike. Posvetimo se izvornim posnetkom stanja, kot je sistemsko ciklično aerosnemanje (CAS), in iz njega izvedenemu proizvodu, ortofotu. Kakovost ortofota je precej odvisna od kakovosti modela reliefa. Topografski podatki so vodeni posamično v sklopu posameznih vsebinskih baz (REZI, ZK GJI, grafični del katastra stavb) ter združeno v topografskih bazah in kartah različnih ravni podrobnosti (DTK 5, DTK 25, DTK 50, sistem DPK). Analizirano stanje primerjamo s stanjem v nekaterih sosednjih ali primerljivih državah ; Topographic data, an important part of the National Spatial Data Infrastructure, have been given serious attention since Slovenia’s independence. It has become publicly available, updated and harmonised. Financing of topographic data in Slovenia has significantly decreased over the previous decade. As a result, the present status is far from acceptable or expected. The current status of the topographic data, as well as its quality and usability for potential users is discussed in this article. The overview starts with basic source data, aerial surveys, photographs and orthophotos. The quality of orthophotos largely depends on the DTM quality. Topographic data is nowadays organised in thematic datasets (geographical names, building cadastre, etc.) or joined in datasets of different levels of accuracy and details. The status in Slovenia is compared to those in some neighbouring and other comparable countries.

Vzdrževanje podatkov v topografskih bazah je ena od pomembnejših nalog organizacij, ki te podatkovne baze vodijo. Eden od pomembnih podatkovnih slojev v topografskih bazah so podatki o stavbah. V člankusta opisani metoda za samodejen zajem stavb iz digitalnega modela površja in multispektralnega ortofota ter uporaba rezultatov zajema za samodejno iskanje sprememb v topografskih bazah, v katerih se vodijo podatki o stavbah. Začetno masko stavb smo izdelali iz normaliziranega digitalnega modela površja (nDMP). Vegetacijo smo iz maske stavb izločili z modificiranim vegetacijskim indeksom, izračunanim iz infrardečega ortofota ob upoštevanju indeksa senc in teksture nDMP. Na končni maski smo stavbe vektorizirali z uporabo transformacije Radon. Rezultate samodejnega zajema stavb smo primerjali s katastrom stavb in dejanskim stanjem na terenu. Ssamodejnim postopkom smo našli 94,4 % vseh stavb na območju in ocenili, da je opisana metoda primerna za zajem podatkov o stavbah za topografske baze v merilih 1 : 10 000 in manj. Rezultat samodejnegaiskanja sprememb (popolnost 93,5 % in pravilnost 78,4 %) kaže, da je opisana metoda primerna za iskanje sprememb med podatki o stavbah : The update of topographic databases is an important task for organizations that maintain them. Building data are one of the important data types in topographic databases. The article describes a method for automatic building extraction from digital surfacemodel and multispectral orthophoto and the use of extraction results for the building change detection in the topographic database. The initial building mask was created from the normalized digital surface model (nDSM).Vegetation was eliminated from the building mask using a modified vegetation index calculated from the infrared orthophoto and also considering the shadow index and the nDMP texture. The finalbuilding mask was vectorised using Radon transform. The results of the automatic building extraction were compared to the building cadastre and the actual situation on the ground. The automatic methoddetected 94.4% of all buildings in the area. We concluded that the described method is appropriate for capturing of the building data for the topographic database in scales 1 : 10 000 and smaller. Automatic change detection results (completeness 93.5% and correctness 78.4%) indicate that the described method is appropriate for building change detection.

Gostota lidarskih točk na površinsko enoto je pomemben podatek pri naročanju lidarskih podatkov, ki odločilno vpliva tudi na ceno lidarskega snemanja. V članku najprej obravnavamo teoretični izračunminimalne gostote lidarskih točk, ki je potrebna za zajem topografskih podatkov v največjih merilih. Za ta namen smo uporabili teorem vzorčenja. Ker pa so topografski objekti in pojavi, ki so predstavljeni na topografskih kartah in v topografskih bazah,velikokrat pod vegetacijo (ceste, vodna telesa itd.), moramo poznati tudi delež prodiranja laserskih žarkov skozi vegetacijo za območje, kjer bomo zajemali topografske podatke. V raziskavi smo na testnemprimeru na območju mesta Nova Gorica izračunali delež prodiranja laserskih žarkov za štiri različne vegetacijske tipe: redko mediteransko vegetacijo, gost termofilen listnati gozd, mešano vegetacijo (travniki, sadovnjaki in gozd) in pozidano območje. S povezavo teoretične minimalne gostote lidarskih točk in deležaprodiranja smo določili minimalno gostoto lidarskih točk za potrebe zajema podatkov na topografskih kartah največjih meril oziroma v topografskih bazah primerljive podrobnosti (od 1 : 1000 do 1 : 10.000).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 forthe 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 ontopographic 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 dataacquisition on topographic maps of the largest scales or in topographic bases of comparable detail (from 1 : 1000 to 1 : 10,000).

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 thearea 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).

In the paper the results of the research on the complete automation of the relative orientation of a stereo pair is presented. The theoretical background needed for understanding this topic is described and the results of testing the algorithms with real data are presented. In general, the relative orientation procedure consists of three phases: input data acquisition, computation ofrelative orientation parameters and estimation of observation errors. In the process of the complete relative orientation automation, the key step is the automation of homologous points acquisition in the stereo area. In the tests presented, the homologous points were acquired with different methods: manually, semiautomatically and fully automatically. The results ofthe computed relative orientation parameters have been compared. It has been concluded that the automation of the relative orientation procedure is successful and reliable if the control of the observation errors estimation is built into the procedure, and,especially, we get the results faster than with the manual or semi-automated method.

V članku so predstavljeni rezultati raziskave avtomatizacije celotnega postopka relativne orientacije stereopara. Opisana so teoretična izhodišča, ki so potrebna za razumevanje problematike, predstavljeni so rezultati testiranja algoritmov na realnih primerih.Postopek relativne orientacije je v splošnem sestavljen iz treh faz: zajema vhodnih podatkov, izračuna parametrov relativne orientacije in ocene pogreškov opazovanj. V procesu popolne avtomatizacije relativne orientacije je ključnega pomena avtomatizacija zajema homolognih točk na stereoobmočju. V testu smo homologne točke zajeli z različnimi metodami: ročno, polavtomatsko in avtomatsko, nato smo rezultate izračuna parametrov relativne orientacije med sebojprimerjali. Ugotovili smo, da avtomatizacija postopka relativne orientacije deluje uspešno in zanesljivo, če v postopek vgradimo nadzor nad oceno pogreškov opazovanj, predvsem pa do rezultatov pridemo hitreje kot z ročno ali polavtomatsko metodo.

Pri zračnem laserskem skeniranju terena se hkrati z registracijo polarnih koordinat beleži tudi intenziteta odbitega laserskega žarka. Ker sam 3D lidarski oblak točk ne vsebuje informacij o tem, na katerih objektih točke dejansko ležijo, so meritve intenzitete pomemben podatek za identifikacijo objektov in pojavov v prostoru.To potrjuje slika barvno kodiranih vrednosti intenzitete, na kateri lahko razločimo posamezne pojave (asfaltna cesta, trava, zgradba itd.). V raziskavi smo analizirali vrednosti merjene intenzitete na primeru projekta Neusiedler See, ki je del transnacionalnega projektaSISTEMaPARC (Interreg IIIB). Preučevali smo, katere vrste rabe lahko na osnovi vrednosti intenzitete razločimo in tako izvedemo klasifikacijo rabe površin.

Airborne laser scanning of a terrain results, in addition to polar coordinate measurements, in intensity measurement of the reflected laser beam. Because the 3D lidar point cloud itself does not include information about the object types on which points are located,intensity measurements provide the important data for identification of objects and phenomena in the physical space. This is confirmed by the colour coded intensity value image, where particular objects (asphalt road, grass, building etc.) can be recognized. The measuredintensity values have been analyzed within the Neusiedler See project case, part of a transnational project SISTEMaPARC (Interreg IIIB). We have investigated the land use classes that could bedifferentiated on the basis of intensity values thus enabling the land use classification.

Results of the research on the use of orthophoto (DOF5) are represented, obtained by questionnaires that were sent to registered buyers of orthophoto in Slovenia at the end of 2005. The aim of the research was to find out, how often and for what purposes the orthophoto is being used, and especially, what is the opinion of the users about its quality and applicability for their work. As much as 96 % of the questioned population estimated the general quality of orthophoto with regard to their needs as »very good«. The nvestigation has shown also some deficiency of the product and a wish of the users for a new product of larger scale. The knowlege on the product was tested in the questionnaire as well and the results have shown that not all users have been informed sufficiently on the features of the product, thus additional education and/or information on this would be advantageous.

The paper describes the procedure of generating a 3D metric building model using a low-cost program package that operates on principles of multiple-image ray intersection. The advantage of the method is that stereoview is not required and we do not need a photogrammetric instrument or workstation for 3D data acquisition. The method was tested on two buildings. The program package Photomodeler version 5 was used, enabling the complete project accomplishment that includes camera calibration, image measurements, adjustments of object coordinates, generation of surface 3D models and photorendering. The phases of the project are described as well as limitations and problems encountered in practice. The results show good potentials for broad use in different applications.

The article describes the efficiency test of contemporary non-metric digital cameras for photogrammetric application. In the test, the high resolution leica format non-metric digital camera Canon Eos 1Ds was compared with the analogue camera Rolleiflex 6006 metric. The single image method based on the projective transformation was applied. The quality and accuracy of the digital camera was estimated from the co-ordinate differences between the same control and detail points captured from the non-metric and metric images, respectively. The results have shown that the digital non-metric high resolution cameras still do not reach entirely the performance of metric cameras, however they can replace metric cameras in certain applications where around 1 cm geometric accuracy with 10-metre objects is satisfactory.

In the article, the influence of input data for orthophoto map production on the final product is discussed. The quality of orthophoto is mostly influenced by image orientation parameters, quality of the digital elevation model and digital image quality. A short description of orthophoto production procedure is given, and the input data and their impact on the product is treated in more detail. The undestanding of this topic is highly relevant for a correct use of the orthophoto.

Vzdrževanje podatkov v topografskih bazah je ena od pomembnejših nalog organizacij, ki te podatkovne baze vodijo. Eden od pomembnih podatkovnih slojev v topografskih bazah so podatki o stavbah. V člankusta opisani metoda za samodejen zajem stavb iz digitalnega modela površja in multispektralnega ortofota ter uporaba rezultatov zajema za samodejno iskanje sprememb v topografskih bazah, v katerih se vodijo podatki o stavbah. Začetno masko stavb smo izdelali iz normaliziranega digitalnega modela površja (nDMP). Vegetacijo smo iz maske stavb izločili z modificiranim vegetacijskim indeksom, izračunanim iz infrardečega ortofota ob upoštevanju indeksa senc in teksture nDMP. Na končni maski smo stavbe vektorizirali z uporabo transformacije Radon. Rezultate samodejnega zajema stavb smo primerjali s katastrom stavb in dejanskim stanjem na terenu. Ssamodejnim postopkom smo našli 94,4 % vseh stavb na območju in ocenili, da je opisana metoda primerna za zajem podatkov o stavbah za topografske baze v merilih 1 : 10 000 in manj. Rezultat samodejnegaiskanja sprememb (popolnost 93,5 % in pravilnost 78,4 %) kaže, da je opisana metoda primerna za iskanje sprememb med podatki o stavbah ; The update of topographic databases is an important task for organizations that maintain them. Building data are one of the important data types in topographic databases. The article describes a method for automatic building extraction from digital surfacemodel and multispectral orthophoto and the use of extraction results for the building change detection in the topographic database. The initial building mask was created from the normalized digital surface model (nDSM).Vegetation was eliminated from the building mask using a modified vegetation index calculated from the infrared orthophoto and also considering the shadow index and the nDMP texture. The finalbuilding mask was vectorised using Radon transform. The results of the automatic building extraction were compared to the building cadastre and the actual situation on the ground. The automatic methoddetected 94.4% of all buildings in the area. We concluded that the described method is appropriate for capturing of the building data for the topographic database in scales 1 : 10 000 and smaller. Automatic change detection results (completeness 93.5% and correctness 78.4%) indicate that the described method is appropriate for building change detection.