Advances in small-scale map projection research

The main objective of this paper is to review previous and current trends in small-scale map projection research, and to discuss the work that has been done by this author in relation to similar work by others. Attention is focused on three issues: (a) evaluation of map projection distortion, (b) development of low-error map projections, (c) automated (and semi-automated) map projection selection. It is hoped that this paper will give the reader a good impression of the marked evolution of map projection science over the last forty years, of changes in the way map projections are used (or will be used in the near future), and of the important role the rapidly increasing, widespread use of computers has played in this process.Dit artikel geeft een overzicht van vroeger en recent onderzoek rond kaartprojecties in de kleinschalige cartografie, en situeert het werk van de auteur binnen het geheel aan onderzoek dat binnen dit domein plaatsvindt. De aandacht is toegespitst op drie thema’s : (a) evaluatie van vervorming op kaartprojecties, (b) ontwikkeling van nieuwe projecties met een geringe vervorming, (c) geautomatiseerde (en semi-geautomatiseerde) methoden voor het selecteren van kaartprojecties. Hopelijk geeft dit artikel de lezer een goed beeld van de markante evolutie die het onderzoek rond kaartprojecties in de laatste veertig jaar heeft doorgemaakt, van veranderingen in de wijze waarop kaartprojecties gebruikt, of in de toekomst gebruikt zullen worden, en van de belangrijke rol die het snel toegenomen gebruik van computers in deze evolutie gespeeld heeft

Use of multi-angle high-resolution imagery and 3D information for urban land-cover classification: a case study on Istanbul

The BELSPO-MAMUD project focuses on the use of Remote Sensing data for measuring and modelling urban dynamics. Remote sensing is a wonderful tool to produce long time-series of high resolution maps of sealed surface useful for this purpose. In the urban context of Istanbul, a very dynamic city, recent high resolution satellite images and medium resolution images from the past have been exploited to calibrate and validate a regression-based sub-pixel classification method allowing this production. In this context it’s a tricky task for several reasons: prominent occurrence of shadowed and occluded areas and urban canyons, spectral confusions between urban and non-urban materials at ground and roof levels, moderately hilly relief ... To cope with these difficulties the combined use of three types of data may be helpful: diachronic (i), multi-angle and 3D data. A master multispectral and panchromatic QuickBird image and a panchromatic Ikonos stereopair, all acquired in March 2002, were used in combination with a multispectral and panchromatic Ikonos image of May 2005. A DSM was generated from the Ikonos stereopair and building vector file. It was used for orthorectification, building height estimation and classification procedure. The area covered by the high resolution products was divided in 3 partitions and each one was classified independently. This application demonstrates that recent high resolution land-cover classification produced using multi-date, multi-angle and DSM can be used to produce sealed surface maps from longer timeseries of medium resolution images over large urban areas enabling so the analysis of urban dynamics

Use of Earth observation for monitoring soil sealing trends in Flanders and Brussels between 1976 and 2013

The on-going growth of urban area in Flanders and in the Brussels Capital Region over the past decades has resulted in a highly sprawled urban tissue, consisting of large and smaller urban agglomerations, connected by a well-developed transportation network. The conversion of open land to urban area is accompanied by an increase in soil sealing, affecting the hydrological cycle and the urban climate. Despite a growing interest in monitoring the process of soil sealing in urban areas, to date no detailed information on the presence and evolution of sealed surfaces is available for Flanders. In this paper a linear regression unmixing approach is proposed to map and monitor changes of sealed surface cover at the regional scale, using medium as well as high resolution remote sensing data. Applied to Flanders and the Brussels Capital Region, a total sealed area of 2687 km² for 2013 is found, corresponding to an increase of 82% since 1976. Residential areas account for nearly half of the sealed area and show the largest increase in sealed surface cover over the past 37 years.De toenemende verstedelijking van Vlaanderen en het Brussels Hoofdstedelijk Gewest in de laatste decennia heeft geleid tot een sterk gefragmenteerde stedelijke ruimte die zich heeft ontwikkeld rond grote en kleinere bebouwingskernen en langs het dicht vertakte transportnetwerk dat deze kernen verbindt. De conversie van open ruimte naar stedelijk gebied gaat gepaard met een toenemende afdichting van de bodem met verharde oppervlakken. Deze afdichting heeft een impact heeft op de hydrologische cyclus en het klimaat van verstedelijkte zones. Ondanks de groeiende aandacht voor het opvolgen van bodemafdichting in verstedelijkte gebieden is op dit moment geen gedetailleerde informatie omtrent de evolutie van bodemverharding in Vlaanderen beschikbaar. In dit artikel wordt een methode voorgesteld om bodemverharding en veranderingen in verharding doorheen de tijd op regionale schaal in kaart te brengen, gebruik makend van satellietdata. De methode is gebaseerd op spectrale ontmenging van medium resolutie satellietdata, en gebruikt gedetailleerd, hoge resolutie beeldmateriaal om een op lineaire regressie gebaseerd ontmengingsmodel te calibreren en valideren. Toepassing van de methode op Vlaanderen en het Brussels Hoofdstedelijk Gewest resulteert voor 2013 in een totale verharde oppervlakte van 2687 km2, wat overeenstemt met een toename van 82% sinds 1976. Bijna de helft van de verharde oppervlakte situeert zich in residentiële gebieden, die vergeleken met andere landgebruiken ook de grootste toename in verharding kennen

Editorial: Special theme issue “Mapping, monitoring and modelling of urban areas”

Today 54% of the world’s population is living in urban areas, a number that is expected to rise to 66% by 2050 (United Nations, 2014). The increase in urban population over the last decades has led to a rapid growth of urban areas. This urban land consumption, if not managed well, puts strong pressure on open spaces and increases the demand for ecosystem services while endangering their supply (Elmqvist et al., 2015; Burkhard et al., 2012). Uncontrolled urban growth may also lead to higher co..

Improving distributed runoff prediction in urbanized catchments with remote sensing based estimates of impervious surface cover

The amount and intensity of runoff on catchment scale are strongly determined by the presence of impervious land-cover types, which are the predominant cover types in urbanized areas. This paper examines the impact of different methods for estimating impervious surface cover on the prediction of peak discharges, as determined by a fully distributed rainfall-runoff model (WetSpa), for the upper part of the Woluwe River catchment in the southeastern part of Brussels. The study shows that detailed information on the spatial distribution of impervious surfaces, as obtained from remotely sensed data, produces substantially different estimates of peak discharges than traditional approaches based on expert judgment of average imperviousness for different types of urban land use. The study also demonstrates that sub-pixel estimation of imperviousness may be a useful alternative for more expensive high-resolution mapping for rainfall-runoff modelling at catchment scale

The data concept behind the data: From metadata models and labelling schemes towards a generic spectral library

Spectral libraries play a major role in imaging spectroscopy. They are commonly used to store end-member and spectrally pure material spectra, which are primarily used for mapping or unmixing purposes. However, the development of spectral libraries is time consuming and usually sensor and site dependent. Spectral libraries are therefore often developed, used and tailored only for a specific case study and only for one sensor. Multi-sensor and multi-site use of spectral libraries is difficult and requires technical effort for adaptation, transformation, and data harmonization steps. Especially the huge amount of urban material specifications and its spectral variations hamper the setup of a complete spectral library consisting of all available urban material spectra. By a combined use of different urban spectral libraries, besides the improvement of spectral inter- and intra-class variability, missing material spectra could be considered with respect to a multi-sensor/ -site use. Publicly available spectral libraries mostly lack the metadata information that is essential for describing spectra acquisition and sampling background, and can serve to some extent as a measure of quality and reliability of the spectra and the entire library itself. In the GenLib project, a concept for a generic, multi-site and multi-sensor usable spectral library for image spectra on the urban focus was developed. This presentation will introduce a 1) unified, easy-to-understand hierarchical labeling scheme combined with 2) a comprehensive metadata concept that is 3) implemented in the SPECCHIO spectral information system to promote the setup and usability of a generic urban spectral library (GUSL). The labelling scheme was developed to ensure the translation of individual spectral libraries with their own labelling schemes and their usually varying level of details into the GUSL framework. It is based on a modified version of the EAGLE classification concept by combining land use, land cover, land characteristics and spectral characteristics. The metadata concept consists of 59 mandatory and optional attributes that are intended to specify the spatial context, spectral library information, references, accessibility, calibration, preprocessing steps, and spectra specific information describing library spectra implemented in the GUSL. It was developed on the basis of existing metadata concepts and was subject of an expert survey. The metadata concept and the labelling scheme are implemented in the spectral information system SPECCHIO, which is used for sharing and holding GUSL spectra. It allows easy implementation of spectra as well as their specification with the proposed metadata information to extend the GUSL. Therefore, the proposed data model represents a first fundamental step towards a generic usable and continuously expandable spectral library for urban areas. The metadata concept and the labelling scheme also build the basis for the necessary adaptation and transformation steps of the GUSL in order to use it entirely or in excerpts for further multi-site and multi-sensor applications

A web application for browsing a folk music collection

V diplomski nalogi je predstavljena realizacija spletne aplikacije, ki uporabniku omogoča pregled zbirke ljudske glasbe in iskanje po njej. Razvili smo idejo in jo implementirali v programskem jeziku C#. Uporabili smo ogrodje .NET, arhitekturo MVC5, strežnik MSSQL in iskalni strežnik Elasticsearch. Spletna aplikacija omogoča splošno iskanje ljudske glasbe in iskanje z uporabo filtrov. Za iskanje s filtri smo uporabili Googlov pristop pametnega iskanja. Možen je tudi vnos melodije preko tekstovnega polja ali z uporabo klaviature in tudi iskanje po melodiji. Zaradi uporabe Elasticsearch strežnika sta iskanje in prikaz rezultatov hitra. Omogočen je tudi prikaz notnega zapisa, PDF datotek ter predvajanje avdio in MIDI datotek posameznih pesmi.The thesis presents the realization of a web application that allows the user to review a folk music collection and search within it. We developed the idea and implemented it using C# programming language. We used the .NET framework, MVC5 architecture, MSSQL server and Elasticsearch search server. The Web application provides general searching of folk music and searching with the help of filters. We used Google’s smart search approach for searching with the filters. We can enter a melody in the text field or use the keyboard to search by melody. Searching and displaying of results are fast, due to the use of the Elasticsearch server. The application also shows musical notations, PDF-files and can play audio and MIDI files

Full Hierarchic Versus Non-Hierarchic Classification Approaches for Mapping Sealed Surfaces at the Rural-Urban Fringe Using High-Resolution Satellite Data

Since 2008 more than half of the world population is living in cities and urban sprawl is continuing. Because of these developments, the mapping and monitoring of urban environments and their surroundings is becoming increasingly important. In this study two object-oriented approaches for high-resolution mapping of sealed surfaces are compared: a standard non-hierarchic approach and a full hierarchic approach using both multi-layer perceptrons and decision trees as learning algorithms. Both methods outperform the standard nearest neighbour classifier, which is used as a benchmark scenario. For the multi-layer perceptron approach, applying a hierarchic classification strategy substantially increases the accuracy of the classification. For the decision tree approach a one-against-all hierarchic classification strategy does not lead to an improvement of classification accuracy compared to the standard all-against-all approach. Best results are obtained with the hierarchic multi-layer perceptron classification strategy, producing a kappa value of 0.77. A simple shadow reclassification procedure based on characteristics of neighbouring objects further increases the kappa value to 0.84

Extraction of topography from stereoscopic SPOT images in remote and hardly accessible areas

info:eu-repo/semantics/publishe