Investigating the effectiveness of an efficient label placement method using eye movement data

This paper focuses on improving the efficiency and effectiveness of dynamic and interactive maps in relation to the user. A label placement method with an improved algorithmic efficiency is presented. Since this algorithm has an influence on the actual placement of the name labels on the map, it is tested if this efficient algorithms also creates more effective maps: how well is the information processed by the user. We tested 30 participants while they were working on a dynamic and interactive map display. Their task was to locate geographical names on each of the presented maps. Their eye movements were registered together with the time at which a given label was found. The gathered data reveal no difference in the user's response times, neither in the number and the duration of the fixations between both map designs. The results of this study show that the efficiency of label placement algorithms can be improved without disturbing the user's cognitive map. Consequently, we created a more efficient map without affecting its effectiveness towards the user

Open source GIS for HIV/AIDS management

<p>Abstract</p> <p>Background</p> <p>Reliable access to basic services can improve a community's resilience to HIV/AIDS. Accordingly, work is being done to upgrade the physical infrastructure in affected areas, often employing a strategy of decentralised service provision. Spatial characteristics are one of the major determinants in implementing services, even in the smaller municipal areas, and good quality spatial information is needed to inform decision making processes. However, limited funds, technical infrastructure and human resource capacity result in little or no access to spatial information for crucial infrastructure development decisions at local level.</p> <p>This research investigated whether it would be possible to develop a GIS for basic infrastructure planning and management at local level. Given the resource constraints of the local government context, particularly in small municipalities, it was decided that open source software should be used for the prototype system.</p> <p>Results</p> <p>The design and development of a prototype system illustrated that it is possible to develop an open source GIS system that can be used within the context of local information management. Usability tests show a high degree of usability for the system, which is important considering the heavy workload and high staff turnover that characterises local government in South Africa. Local infrastructure management stakeholders interviewed in a case study of a South African municipality see the potential for the use of GIS as a communication tool and are generally positive about the use of GIS for these purposes. They note security issues that may arise through the sharing of information, lack of skills and resource constraints as the major barriers to adoption.</p> <p>Conclusion</p> <p>The case study shows that spatial information is an identified need at local level. Open source GIS software can be used to develop a system to provide local-level stakeholders with spatial information. However, the suitability of the technology is only a part of the system – there are wider information and management issues which need to be addressed before the implementation of a local-level GIS for infrastructure management can be successful.</p

SEMIÓTICA E A TEORIA DA VISUALIZAÇÃO CARTOGRÁFICA: CONSIDERAÇÕES NA ANÁLISE DO PROJETO CARTOGRÁFICO

Este artigo tem como objetivo refletir sobre as discussões contemporâneas advindas da teoria da visualização cartográfica, com ênfase na elaboração dos signos gráficosutilizados em mapas analógicos. Para tanto, buscamos fazer apontamentos sobre as etapas no desenvolvimento do projeto cartográfico, valendo-nos, sobretudo, deparâmetros da semiótica de extração peirceana. Por intermédio da aplicação da leitura semiótica em mapas topográficos e sinóticos apresentaremos as particularidades das estratégias de cada produto, a fim de se mostrar uma alternativa aos autores de mapa para a elaboração de signos gráficos mais eficazes para cada tipo de usuário. Compararemos, também, as perspectivas existentes sobre as teorias do conhecimento, apontando novas questões a serem pensadas sobre o processo de construção da informação espacial adquirida dos mapas

Farm 2.0 Using Wordpress to Manage Geocontent and Promote Regional Food Products

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies.Recent innovations in geospatial technology have dramatically increased the utility and ubiquity of cartographic interfaces and spatially-referenced content on the web. Capitalizing on these developments, the Farm2.0 system demonstrates an approach to manage user-generated geocontent pertaining to European protected designation of origin (PDO) food products.Wordpress, a popular open-source publishing platform, supplies the framework for a geographic content management system, or GeoCMS, to promote PDO products in the Spanish province of Valencia. The Wordpress platform is modified through a suite of plug-ins and customizations to create an extensible application that could be easily deployed in other regions and administrated cooperatively by distributed regulatory councils. Content, either regional recipes or map locations for vendors and farms, is available for syndication as a GeoRSS feed and aggregated with outside feeds in a dynamic web map

A Pipeline of 3D Scene Reconstruction from Point Clouds

3D technologies are becoming increasingly popular as their applications in industrial, consumer, entertainment, healthcare, education, and governmental increase in number. According to market predictions, the total 3D modeling and mapping market is expected to grow from $1.1 billion in 2013 to$7.7 billion by 2018. Thus, 3D modeling techniques for different data sources are urgently needed. This thesis addresses techniques for automated point cloud classification and the reconstruction of 3D scenes (including terrain models, 3D buildings and 3D road networks). First, georeferenced binary image processing techniques were developed for various point cloud classifications. Second, robust methods for the pipeline from the original point cloud to 3D model construction were proposed. Third, the reconstruction for the levels of detail (LoDs) of 1-3 (CityGML website) of 3D models was demonstrated. Fourth, different data sources for 3D model reconstruction were studied. The strengths and weaknesses of using the different data sources were addressed. Mobile laser scanning (MLS), unmanned aerial vehicle (UAV) images, airborne laser scanning (ALS), and the Finnish National Land Survey’s open geospatial data sources e.g. a topographic database, were employed as test data. Among these data sources, MLS data from three different systems were explored, and three different densities of ALS point clouds (0.8, 8 and 50 points/m2) were studied. The results were compared with reference data such as an orthophoto with a ground sample distance of 20cm or measured reference points from existing software to evaluate their quality. The results showed that 74.6% of building roofs were reconstructed with the automated process. The resulting building models provided an average height deviation of 15 cm. A total of 6% of model points had a greater than one-pixel deviation from laser points. A total of 2.5% had a deviation of greater than two pixels. The pixel size was determined by the average distance of input laser points. The 3D roads were reconstructed with an average width deviation of 22 cm and an average height deviation of 14 cm. The results demonstrated that 93.4% of building roofs were correctly classified from sparse ALS and that 93.3% of power line points are detected from the six sets of dense ALS data located in forested areas. This study demonstrates the operability of 3D model construction for LoDs of 1-3 via the proposed methodologies and datasets. The study is beneficial to future applications, such as 3D-model-based navigation applications, the updating of 2D topographic databases into 3D maps and rapid, large-area 3D scene reconstruction. 3D-teknologiat ovat tulleet yhä suositummiksi niiden sovellusalojen lisääntyessä teollisuudessa, kuluttajatuotteissa, terveydenhuollossa, koulutuksessa ja hallinnossa. Ennusteiden mukaan 3D-mallinnus- ja -kartoitusmarkkinat kasvavat vuoden 2013 1,1 miljardista dollarista 7,7 miljardiin vuoteen 2018 mennessä. Erilaisia aineistoja käyttäviä 3D-mallinnustekniikoita tarvitaankin yhä enemmän. Tässä väitöskirjatutkimuksessa kehitettiin automaattisen pistepilviaineiston luokittelutekniikoita ja rekonstruoitiin 3D-ympäristöja (maanpintamalleja, rakennuksia ja tieverkkoja). Georeferoitujen binääristen kuvien prosessointitekniikoita kehitettiin useiden pilvipisteaineistojen luokitteluun. Työssä esitetään robusteja menetelmiä alkuperäisestä pistepilvestä 3D-malliin eri CityGML-standardin tarkkuustasoilla. Myös eri aineistolähteitä 3D-mallien rekonstruointiin tutkittiin. Eri aineistolähteiden käytön heikkoudet ja vahvuudet analysoitiin. Testiaineistona käytettiin liikkuvalla keilauksella (mobile laser scanning, MLS) ja ilmakeilauksella (airborne laser scanning, ALS) saatua laserkeilausaineistoja, miehittämättömillä lennokeilla (unmanned aerial vehicle, UAV) otettuja kuvia sekä Maanmittauslaitoksen avoimia aineistoja, kuten maastotietokantaa. Liikkuvalla laserkeilauksella kerätyn aineiston osalta tutkimuksessa käytettiin kolmella eri järjestelmällä saatua dataa, ja kolmen eri tarkkuustason (0,8, 8 ja 50 pistettä/m2) ilmalaserkeilausaineistoa. Tutkimuksessa saatuja tulosten laatua arvioitiin vertaamalla niitä referenssiaineistoon, jona käytettiin ortokuvia (GSD 20cm) ja nykyisissä ohjelmistoissa olevia mitattuja referenssipisteitä. 74,6 % rakennusten katoista saatiin rekonstruoitua automaattisella prosessilla. Rakennusmallien korkeuksien keskipoikkeama oli 15 cm. 6 %:lla mallin pisteistä oli yli yhden pikselin poikkeama laseraineiston pisteisiin verrattuna. 2,5 %:lla oli yli kahden pikselin poikkeama. Pikselikoko määriteltiin kahden laserpisteen välimatkan keskiarvona. Rekonstruoitujen teiden leveyden keskipoikkeama oli 22 cm ja korkeuden keskipoikkeama oli 14 cm. Tulokset osoittavat että 93,4 % rakennuksista saatiin luokiteltua oikein harvasta ilmalaserkeilausaineistosta ja 93,3 % sähköjohdoista saatiin havaittua kuudesta tiheästä metsäalueen ilmalaserkeilausaineistosta. Tutkimus demonstroi 3D-mallin konstruktion toimivuutta tarkkuustasoilla (LoD) 1-3 esitetyillä menetelmillä ja aineistoilla. Tulokset ovat hyödyllisiä kehitettäessä tulevaisuuden sovelluksia, kuten 3D-malleihin perustuvia navigointisovelluksia, topografisten 2D-karttojen ajantasaistamista 3D-kartoiksi, ja nopeaa suurten alueiden 3D-ympäristöjen rekonstruktiota

Reference frame densifications for Nordic and Baltic countries - From local analysis to common and consistent GNSS solutions

Terrestrial, Earth-fixed, reference frames are fundamental, but often unnoticeable, components for modern societies. Today, regional terrestrial reference frames are created and maintained by the measurement of continuously operating Global Navigation Satellite System (GNSS) reference stations. In Fennoscandia, glacial isostatic adjustment (GIA) causes deformation, also known as postglacial rebound, decreasing the accuracy of national static reference frames referring to the European Terrestrial Reference System 1989 (ETRS89). Considering the deformation is thus a necessity to accurately transform coordinates from the International Terrestrial Reference Frame (ITRF) to national ETRS89 realisations such as EUREF-FIN in Finland. This dissertation focused on estimating densified reference frame realisations in the global reference frames for the Nordic and Baltic countries. The work was carried out in the GNSS Analysis Centre project of the Nordic Geodetic Commission (NKG). It builds on eight local analysis centres, one in each country, processing its sub-net. The emphasis of the dissertation was on developing methods for combination of the sub-nets, analysis of the time series, and estimating a multi-year position and velocity solution, including uncertainties of the station velocities. The results showed that the sub-net solutions were consistent with the combined solution within 1–2 mm. The distribution of the GNSS processing into local sub-nets thus strengthened the daily solutions due to the redundantly processed reference stations. The station-wise position time series were analysed for offsets both manually and with the developed automatic approach with a 74 % success rate in respect to the manual interpretation. Station velocities were estimated for approximately 270 stations from daily position solutions. The lengths of time series varied between 3 and 20 years. Uncertainty levels of 0.10, 0.10, and 0.25 mm/y for the north, east, and up components respectively were reached with 10 years of data for more than 90 % of stations. The detailed understanding of the GNSS time series in the Nordic and Baltic countries will enhance the quality of the European and global terrestrial reference frame realisations, because some of the stations contribute with the same data to those solutions. The densified reference frame solutions will be utilised in the maintenance of the national geodetic reference frames, including deformation modelling and the development of the accurate coordinate transformations. This will ultimately extend the lifetime of the national reference frames like EUREF-FIN

Finnish permanent GNSS network FinnRef - evolution towards a versatile positioning service

The doctoral thesis is conducted in collaboration with Aalto University and Finnish Geospatial Research Institute.The National Land Survey of Finland maintains the FinnRef network of continuously operating GNSS reference stations (CORS). FinnRef is the basis of the EUREF-FIN reference frame in Finland. Continuous time series ensure an accurate link between global GNSS-based coordinates and the national reference frame. In a CORS network it is essential that coordinates and coordinate time series of the reference stations are up to date, accurate and free from biases. In this dissertation we introduce the development of FinnRef from a network of 13 GPS stations into a versatile modern positioning service. Both old and new FinnRef stations are explained and it is shown how a high quality CORS station should be established today. We were one of the first groups to show the annual periodicity of GNSS time series. In Finland, land uplift is of high importance since it changes the coordinates continuously. We compared our uplift rates to independent results (tide gauges, precise levelling, GPS results of the BIFROST group). Agreement was very good showing that GPS is a powerful tool for monitoring the land uplift in Finland. Using a baseline in Lithuania we tested an idea to validate GPS processing parameters against metrological ground truth. The length of the baseline is traceable to the definition of the metre with an uncertainty based on our calibrations. The test was successful and showed that for most accurate measurements individually calibrated antennas must be used.After the first renewal phase of FinnRef we showed that our national network of 20 stations can provide NRTK corrections of the same accuracy level as services having five times more stations. The challenge was the reliability of individual coordinate measurements but this can be overcome by proper use of repeated measurements. One of the most important results of this dissertation was that we showed the power of using metrological ground truth for validating GPS. The results of this dissertation will enable the creation of a dense GNSS based velocity field for intra-plate deformation models. This will improve the accuracy of transformations from measured GNSS coordinates to the national reference frame and make possible an accurate, reliable (semi)dynamic reference frame in Finland. It is also noteworthy that we showed how the FINPOS positioning service based on FinnRef data could give citizens direct access to the national EUREF-FIN reference frame. FinnRef could also be used as a backbone for GNSS corrections needed for intelligent traffic applications in Finland.Maanmittauslaitos kerää satelliittipaikannusjärjestelmien (GNSS) lähettämää dataa jatkuvasti rekisteröivien FinnRef-tukiasemien avulla. Maanlaajuinen FinnRef-verkko on Suomen EUREF-FIN -vertauskehyksen runko. Verkon keräämät pitkät aikasarjat mahdollistavat tarkkojen muunnosmallien johtamisen satelliittipaikannusjärjestelmien tuottamien maailmanlaajuisten koordinaattien ja kansallisen EUREF-FIN -järjestelmän välille. On oleellista, että pysyvien GNSS-asemien tuottamat koordinaatit ja koordinaattien aikasarjat ovat laadukkaita ja virheettömiä. Tässä väitöskirjassa esitetään Suomen pysyvän GNSS-verkon kehitys 13 aseman GPS-asemien verkosta kohti tiheämpää ja monipuolista paikannuspalvelua. Työssä esitellään alkuperäisen FinnRef-verkon ja uudistetun verkon rakenne, toimintaperiaatteet ja uusin tieto siitä kuinka asemat tulee tänä päivänä perustaa. Olimme yksi ensimmäisistä tutkimusryhmistä, jotka raportoivat GPS-aikasarjoissa selkeää vuotuista periodisuutta. Suomessa eräs koordinaatteja jatkuvasti muuttava ilmiö on maankohoaminen. Vertasimme omia GPS:llä saatuja maankohoamisarvoja riippumattomiin tuloksiin (toistetut tarkkavaaitukset, mareografihavainnot ja kansainvälisen BIFROST-tutkimusryhmän eri metodilla tekemä GPS-analyysi). Yhteensopivuus oli hyvä ja osoitti GPS:n olevan tehokas työkalu myös maankuoren pystyliikkeiden seurantaan. Testasimme Liettuassa olevalla perusviivalla mahdollisuutta validoida GPS-laskentaparametreja metrologisesti luotettavaan referenssimittaukseen. Mittauksen epävarmuusketju on tekemämme kalibroinnin perusteella jäljitettävissä metrin määritelmään. Testi osoittautui menestykselliseksi ja osoitimme, että tarkimpiin mahdollisiin mittauksiin jokainen GPS-antenni tulee kalibroida yksilönä. Ensimmäisen FinnRef-verkon uudistuksen jälkeen osoitimme, että valtakunnallisella 20 tukiaseman GNSS verkolla voidaan päästä samalle tarkkuustasolle kuin viisi kertaa enemmän asemia olevissa palveluissa. Haasteeksi tulee yksittäisten mittausten luotettavuus, joka voidaan ratkaista toistomittauksin. Väitöskirjan tärkeimpiä tuloksia oli osoittaa metrologisen lähestymistavan hyväksikäytön hyödyllisyys validoitaessa GNSS-laskentaparametreja. Tulokset mahdollistavat entistä tarkemman GNSS-tukiasemien dataan perustuvan maankuoren liikemallien luomisen, joka tarkentaa kansainvälisten ja kansallisen koordinaattijärjestelmien välistä muunnosta sekä aikariippuvan koordinaattijärjestelmän. Osoitimme myös, kuinka FinnRef-verkkoon perustuva FINPOS-paikannuspalvelu mahdollistaisi kansalaisille saumattoman pääsyn kansalliseen EUREF-FIN -järjestelmään. FinnRef-verkkoa voitaisiin hyödyntää myös runkoverkkona, joka voi osaltaan auttaa parantamaan älyliikenteen paikannuksen tarkkuutta

Improving accessibility for pederstrians with geographic information

Osajulkaisut: Publication 1: Mari Laakso, Tapani Sarjakoski, and L. Tiina Sarjakoski. 2011. Improving accessibility information in pedestrian maps and databases. Cartographica, volume 46, number 2, pages 101-108. University of Toronto. DOI:10.3138/carto.46.2.101 Publication 2: L. Tiina Sarjakoski, Pyry Kettunen, Hanna-Marika Flink, Mari Laakso, Mikko Rönneberg, and Tapani Sarjakoski. 2012. Analysis of verbal route descriptions and landmarks for hiking. Personal and Ubiquitous Computing, volume 16, number 8, pages 1001-1011. DOI:10.1007/s00779-011-0460-7 Publication 3: Mari Laakso, Tapani Sarjakoski, Lassi Lehto, and L. Tiina Sarjakoski. 2013. An information model for pedestrian routing and navigation databases supporting universal accessibility. Cartographica, volume 48, number 2, pages 89-99. University of Toronto. DOI:10.3138/carto.48.2.1837 Publication 4: Mari Laakso and L. Tiina Sarjakoski. 2010. Sonic maps for hiking—Use of sound in enhancing the map use experience. The Cartographic Journal, volume 47, number 4, pages 300-307. DOI:10.1179/000870410X12911298276237 Publication 5: Mari Laakso, Hanna-Marika Halkosaari, Tapani Sarjakoski, and L. Tiina Sarjakoski. 2013. User experiences with voice-based descriptive map content in a hiking context. In: Thomas Jekel, Adrijana Car, Josef Strobl, and Gerald Griesebner (editors). Creating the GISociety. Proceedings of the GI_Forum 2013 Conference. Salzburg, Austria. 2-5 July 2013. Berlin / Offenbach, Germany. Herbert Wichmann Verlag, VDE Verlag. Pages 49-58. ISBN 978-3-87907-532-4. DOI:10.1553/giscience2013s49Environments can be made more accessible by offering users information about barriers and objects that might hinder their progress, thus enabling more information about accessible routes. The study delineates the relevant geospatial information needed to describe the accessibility of an environment. Even though laws, acts and regulations give thorough building requirements for creating accessible environments, there is no holistic approach in geospatial data collection to represent the accessibility of geographical spaces. In this thesis, an information model is presented for representing the pedestrian environment. The model allows for accessibility issues and enables the use of geospatial information in pedestrian navigation applications. In addition to data contents and data modelling, this research studies how accessibility can be further increased by way of sound when communicating geospatial information. By communicating the geospatial information via sound the information content can be enhanced and usability improved. Sonic maps create remote access to nature and enhance the accessibility of a place. In this thesis, the fundamental aim was to study the information requirements in particular situations where different kinds of pedestrian users determine which route they might successfully complete. The results of the thesis will help data providers collect and store geospatial information, while taking accessibility issues into account, and hopefully it will raise awareness about issues pertaining to universal accessibility. Albeit, the main effort should focus on building accessible environments; in certain situations, people face hindrances and geospatial information could enable users overcome them.Ympäristöistä voidaan tehdä saavutettavampia tarjoamalla käyttäjille tietoa mahdollisista esteistä tai muista kulkua vaikeuttavista kohteista. Tässä tutkimuksessa määritellään tarvittava paikkatieto, jolla jalankulkijan ympäristö ja sen esteettömyys voidaan kuvata. Esteettömien ympäristöjen luomiseksi on olemassa joukko lakeja ja asetuksia, mutta ympäristön esteettömyyden kuvaamiseksi tarvittavalle paikkatiedolle ei ole määritelty kattavaa keräys- ja esitysmuotoa. Tässä väitöskirjassa esitellään tietomalli, jolla jalankulkijan ympäristö ja sen esteettömyys voidaan kuvata. Malliin voidaan sisällyttää esteettömyyttä kuvaavia tietoja ja se mahdollistaa tämän tiedon käytön myös navigointisovelluksilla. Tietosisällön ja sen mallintamisen lisäksi tässä työssä on tutkittu kuinka ympäristön saavutettavuutta voidaan lisätä kommunikoimalla paikkatietoa myös äänen avulla. Äänen avulla voidaan paikkatiedon määrää ja laatua sekä sen käytettävyyttä lisätä. Äänikartoilla voidaan luoda eräänlainen etäyhteys kuvattuun ympäristöön ja sen avulla lisätä ympäristön saavutettavuutta. Tämän väitöskirjan tavoitteena on määrittää erilaisten käyttäjien vaatima paikkatieto tilanteissa, joissa heidän on tehtävä päätös pystyvätkö he kulkemaan valitsemansa reitin. Tämän työn tulokset auttavat paikkatiedon tarjoajia keräämään ja tallentamaan paikkatietoa niin, että se kuvaa myös ympäristön esteettömyyttä. Ympäristöjen esteettömäksi rakentamisen tulisi edelleen olla ensisijainen tavoite, mutta koska jotkut käyttäjät tietyissä tilanteissa edelleen kohtaavat esteettömyysongelmia, heitä voitaisiin paikkatiedon avulla auttaa väistämään ne

Towards a future cadastral system: An exploration of the Finnish case

Cadastral system as the 'where' component of a property rights system is central to effective land markets, land use and sustainable development. The foundation of any cadastral system, the relationship between people and land, is constantly altering and cadastral systems as well have evolved over time in response to these changes. The focus of this dissertation is on understanding the cadastral system dynamism, and more specifically, the potential future changes of cadastral systems. Empirically the main focus is on the Finnish cadastral system that presents an example of a mature cadastral system with long traditions on registration of land related interests. This dissertation suggests that the future of cadastral systems should be approached from a holistic and systemic perspective and, therefore, integrates concepts and knowledge from the disciplines of futures studies and socio-technical transition studies. The dissertation adopts a mixed method approach with a greater emphasis on qualitative research methods. Literary sources, a Delphi questionnaire, interviews, and focus group meetings are used in data collection. This dissertation provides a refined and revised understanding of what drives change in the context of land administration and how the mature cadastral systems might develop in the future. Exploration of emerging issues of change reveals the increasing awareness of the multi-purpose role of cadastral systems, as the identified issues range from technology-oriented ones to political, economic, environmental, and social issues. Overall, the findings suggest that the future of cadastral systems is a complex issue that cannot be reduced to individual technologies or innovations. Rather, this dissertation argues that more emphasis should be put on the institutional foundations, i.e., on the elements that coordinate and stabilise the established systems when the goal is to detect distinctively alternative configurations for cadastral systems. The academic value of this thesis is in bridging the gap between land administration literature and futures studies and socio-technical transition studies, and in creating comprehensive understanding of cadastral system dynamism. The base of evidence obtained in this research also provides new and fresh insights to actors of land administration domain