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The Working Group of Geoinformatics of the German Society for Photogrammetry, Remote Sensing and Geoinformation (DGPF) is led by Prof. Jan-Hendrik Haunert from the University of Osnabrück. The working group deals with research questions related to Geo-Information Systems (GIS), such as the integration of GIS and image data, GIS analysis algorithms and geospatial data infrastructures.

Bernhard Höfle joins the working group as new co-chair.

On the 12th and 13th of August 2014, the Smart Simulation Group led by Dr. Mohamed Bakillah of the GIScience Research Group at Heidelberg University organized and hosted an internal workshop for the CAP4Access project partners. The aim of this workshop was to present and discuss the activities, sharing of tasks, ongoing progress and issues with the various partners. Among others, talks were given by Dr. Bakillah, Project Leader at Heidelberg University, about the development of the collaborative tagging and recommendation system; by Dr. Adam Roussel, about the routing and navigation services; and by Amin Mobasheri, about the geo-data quality evaluation service. In addition, representatives of center for social innovation (ZSI) partner, Dr. Christian Voigt, Susanne Dobner, and Patrick Berger presented their ideas and initial sketches about different user stories developed for their pilot test in Vienna.

The talks led to fruitful comments that will be considered to ensure the quality and relevance of the services being developed, as well as outcomes that provide future directions for the next steps. The participants of this workshop were from Heidelberg University, Center for Social Innovation (ZSI), Sozialhelden and Mapping4Change.

Outdoor group photo of workshop participants

Outdoor group photo of workshop participants

A new research paper titled “Understanding the potential relationship between the socio-economic variables and contributions to OpenStreetMap” has been published in the International Journal of Digital Earth.

Abstract: OpenStreetMap (OSM) has seen an exponential increase in the last few years and large volumes of geodata have been received from volunteered individuals. The collected geodata are heterogeneous in terms of different dimensions such as spatial patterns of contributions, quality, patterns of contributing individuals, and type of contributions. Because contributors’ personal information is anonymously stored by the OSM administrators, alternative methods are needed to investigate the role of contributors’ characteristics on their mapping behavior. This study is intended to explore the potential socio-economic characteristics of contributors in highly contributed areas to have better insights about the latent patterns of involved individuals in a highly dynamic state of the most active country in OSM, Germany. A logistic regression model (LRM) is applied to discover the potential correlations between dependent and independent variables. The findings explain that the areas with high population density, middle level of education, high income, high rate of overnight stays, high number of foreigners, and residents aged from certain age groups are more likely to be involved in OSM. Furthermore, the degree of dynamism in OSM is a function of proximity to built-up areas. Finally, concluding remarks concerning the independent variables and model sensitivity are presented.

Further reading: Jokar Arsanjani, J. and Bakillah, M. “Understanding the Potential Relationship between the Socio-Economic Variables and Contributions to OpenStreetMap.” International Journal of Digital Earth (pending). http://dx.doi.org/10.1080/17538947.2014.951081

On tuesday morning a delegation from the ITC (Enschede, Netherlands) visited our GIScience research group in Heidelberg. The visiting group consisted of master students and Prof. Frank Ostermann, who was leading the excursion. Their aim was to get an impression of the multifaceted research that is going on in our group. Some members of our group presented their specific subareas, while providing a broad overview. Each talk was followed by a lively discussion among the students and the speakers. The visit was concluded by a joint lunch in the Mensa of Heidelberg University.

The visiting group from ITC and our speakers

The visiting group from ITC and our speakers

Andreas Reimer, presenting our cartographic research

Andreas Reimer, presenting our cartographic research

On 11th of September, the second experiment for the CAP4Access project for Heidelberg pilot city was performed by Smart Simulation group (led by Mohamed Bakillah) with collaboration of LIDAR research group of Heidelberg University. Bernhard Höfle, Amin Mobasheri and Evelyn Schmitz participated in this fieldwork, using RIEGL VZ-400 laser scanning device in order to collect 3D point clouds in the Heidelberg Altstadt area.

The places for data collection were selected based on the data and attribute requirements such as sidewalk geometries, vertical and horizontal slope, and height of sidewalks as well as surface texture type. The results of this experiment would be later used as a reference data with high accuracy for evaluating the quality of sidewalk information derived from GPS traces (for more information read the first experiment).

The experiment started at 06:00 a.m. and lasted for 5 hours. Almost 1 billion single highly precise 3D measurements were collected. Some minutes of raining caused difficulties, but the participants were quite happy with the efficiency of their work to cover the planned area plus some additional places, and enjoyed having fun with drinking warm coffee in the beautiful old-town of Heidelberg.

Group photo of fieldwork experiment participants

Group photo of fieldwork experiment participants

Setting up the device and getting prepared for data collection

Setting up the device and getting prepared for data collection

Collecting data in a horizontally and vertically sloped street with narrow-wide sidewalks and stoned surface texture

Collecting data in a horizontally and vertically sloped street with narrow-wide sidewalks and stoned surface texture

How can new mobile technologies and social media open up new ways of social engagement and support before, during and in the aftermath of a disaster?

This question is the leitmotiv of the video called “Naturkatastrophen 2.0″ (Natural Disasters 2.0), created by Melanie Eckle and Benjamin Herfort, two undergraduate research assistants of the GIScience group, the students being supervised by Prof. Dr. João Porto de Albuquerque, and founding members of the group “Disaster Mappers Heidelberg”.  The video was invited to be part of the exhibition “Von Atlantis bis heute” (From Atlantis till today) that is organized by and presented at the Reiss-Engelhorn Museum Mannheim in cooperation with Heidelberg University and Technische Universität Darmstadt.

Melanie Eckle, Joao Porto and Christoph Lind (curator) in the opening of the exhibition

Melanie Eckle, Joao Porto de Albuquerque and Christoph Lind (curator) during the opening of the exhibition

The video also presents activities and research results of the GIScience group about the use of Volunteered Geographic Information for Disaster Management in the past few years: from the emergency routing service based on OpenStreetMap developed after the 2010 earthquake in Haiti, passing through the analysis of social media use in the 2013 floods in Germany, up to the “crisis mapping” sessions and other activities of the GIScience team in support of the relief efforts that followed the typhoon Hayian in the Philippines in 2013.

The exhibition shows a historical view of how people of different cultures and eras react to and cope with natural disasters, putting our video in a very nice historical context. It will be open to the public from September 7th 2014 till March 1st 2015. However, if you cannot make it to the exhibition (what we strongly recommend!), you can check out our video online here (in German only as yet, a translation to English will come soon!).

Administrative regions and attached statistical data are often simply displayed by the contentious choropleth technique. A recent research collaboration between researchers from the Technical University Eindhoven, City University London and the GIScience group at Heidelberg University successfully added a new arrow to the quiver of Geovisualisation techniques: The Stenomap.

The stenomap comprises a series of smoothly curving linear glyphs that each represent both the boundary and the area of a polygon. Thematic data can then be coded either between the glyphs or directly on them as in the example on energy consumption of the French regions above. We could show that such a collapse of an area to a line is both possible and even advisable in some cases. Besides exploring this extension to the cartographic design space a new schematisation algorithm was developed allowing for three different design strategies.

We are glad to announce that the early access version of the IEEE VisWeek paper has been published online.

We are pleased to announce that a book edited by Dr. Marco Helbich, Dr. Jamal Jokar Arsanjani, Dr. Micheal Leitner titled “Computational Approaches for Urban Environments” is about to be released shortly. The edited book will be published by Springer in its “Geotechnologies and the Environment” series, edited by Jay D. Gatrell and Ryan R. Jensen. For more detailed information about this series, we refer to the Springer webpage, accessible via the following link http://www.springer.com/series/8088.

This book aims to promote the synergistic usage of advanced computational methodologies in close relationship to geospatial information across cities of different scales. A rich collection of chapters subsumes current research frontiers originating from disciplines such as geography, urban planning, computer science, statistics, geographic information science, and remote sensing. The topics covered in the book are of interest to researchers, postgraduates, practitioners, and professionals. The editors hope that the scientific outcome of this book will stimulate future urban-related international and interdisciplinary research, bringing us closer to the vision of a “new science of cities.”

Here is the content of the book.

————————————-

Preface
Mei-Po Kwan
Department of Geography and Geographic Information Science, University of Illinois at Urbana-Champaign, USA

Computational Approaches for Urban Environments: An Editorial
Marco Helbich1, Jamal Jokar2, Michael Leitner3
1 Department of Human Geography and Spatial Planning, Utrecht University, Netherlands
2 Institute of Geography, University of Heidelberg, Germany
3 Department of Geography and Anthropology, Louisiana State University, USA

Section 1: Spatial Planning and Decision-Making
1. From Fractal Urban Pattern Analysis to Fractal Urban Planning Concepts
Pierre Frankhauser1
1 Université de Franche-Comté, France

2. Knowledge discovery in Spatial Planning Data - A Concept for Cluster Understanding
Martin Behnisch1, Alfred Ultsch2
1 Leibniz Institute of Ecological Urban and Regional Development, Germany
2 Databionic, Philipps-University Marburg, Germany

3. Clustering Contextual Neural Gas: A New Approach for Spatial Planning and Analysis Tasks
Julian Hagenauer1
1 Institute of Geography, University of Heidelberg, Germany

Section 2: Housing and Real Estate
4. Hedonic House Price Modeling based on Multilevel Structured Additive Regression
Alexander Razen1, Wolfgang Brunauer2, Nadja Klein3, Stefan Lang1, Nikolaus Umlauf1
1 Department of Statistics, University of Innsbruck, Austria
2 UniCredit Bank Austria AG, Austria
3 Chairs of Statistics and Econometrics, University of Göttingen, Germany

5. Simple Agents, Complex Emergent City: Agent-Based Modeling of Intraurban Migration
Shipeng Sun1, Steven M. Manson2
1 Institute on the Environment, University of Minnesota, USA
2 Department of Geography, University of Minnesota, USA

6. Quantifying Urban Diversity: Multiple Spatial Measures of Social and Economic Characteristics
Timothy Rosner1, Kevin M. Curtin1
1 Department of Geography and GeoInformation Science, George Mason University, USA

Section 3: Urban Transportation and Mobility
7. Everyday Cycling in Urban Environments: Understanding Behaviours and Constraints in Space-Time
Godwin Yeboah1, Seraphim Alvanides2, Emine Mine Thompson2
1 The Centre for Transport Research, University of Aberdeen, UK
2 Engineering and Environment, Northumbria University, UK

8. Performance Improvements for Large-Scale Traffic Simulation in MATSim
Rashid A. Waraich1, David Charypar1, Michael Balmer2, Kay W. Axhausen1
1 Institute for Transport Planning and Systems, ETH Zurich, Switzerland
2 Senozon AG, Zurich, Switzerland

Section 4: Remote Sensing
9. Recent Advances on 2D and 3D Change Detection in Urban Environments from Remote Sensing Data
Konstantinos Karantzalos1
1 Remote Sensing Laboratory, National Technical University of Athens, Greece

10. Fusion of airborne hyperspectral and LiDAR remote sensing data to study the thermal characteristics of urban environments
Christian Berger1, Frank Riedel1, Johannes Rosentreter1, Enrico Stein2, Sören Hese1, Christiane Schmullius1
1 Department of Earth Observation, University of Jena, Germany
2 Earth Observation Center, German Aerospace Center (DLR), Germany
11. Modeling Urban Land Use Change: Integrating Remote Sensing with Socioeconomic Data
Junmei Tang1
1 Geography and Environmental Systems, University of Maryland, USA

Section 5: Urban Sensing, Social Networks and Social Media
12. Linked Activity Spaces: Embedding Social Networks in Urban Space
Yaoli Wang1,2, Chaogui Kang3,4, Luís M. A. Bettencourt2, Yu Liu3,Clio Andris2,5
1 Deptartment of Geography, University of Georgia, USA
2 Santa Fe Institute, USA
3 Institute of Remote Sensing and Geographical Information Systems, Peking University, Beijing, China
4 Senseable City Lab, Massachusetts Institute of Technology, USA
5 Department of Geography, Pennsylvania State University, USA

13. Using Non-authoritative Sources During Emergencies in Urban Areas
Emily Schnebele1, Christopher Oxendine2, Guido Cervone3, Celso Ferreira4, Nigel Waters5
1 Department of Geography and Geoinformation Science, George Mason University, USA
2 Department of Geography & Environmental Engineering, United States Military Academy, USA
3 Department of Geography, Pennsylvania State University and Research Application Laboratory, National Center for Atmospheric Research, USA
4 Department of Civil & Environmental and Infrastructure Engineering, George Mason University, USA
5 Center for Excellence in GIS, George Mason University, USA

14. Towards a comparative science of cities: using mobile traffic records in New York, London and Hong Kong
Sebastian Grauwin1, Stanislav Sobolevsky1, Simon Moritz2, István Gódor3, Carlo Ratti1
1 Senseable City Lab, Massachusetts Institute of Technology, USA
2 Ericsson Research, Sweden
3 Ericsson Research, Hungary

Epilogue
Paul Longley1
1 Department of Geography, University College London, London, UK

As a task for CAP4Access project, on Monday 11th of August, members of the Smart Simulation group (Mohamed Bakillah, Amin Mobasheri and Sarah Labusga) of GIScience at Heidelberg University performed a field experiment together with people with limited mobilities.

Several GPS trackers (with different characteristics and predefined parameters for data collection) were installed on three wheelchairs and for a selected route in Altstadt area, multiple coordinate points of the position of wheelchairs were collected. This field experiment was done in order to come up with a simple and cost-effective approach for deriving sidewalk paths and its characteristics.

One of the aims of this experiment is to come up with an efficient approach to derive and enrich OpenStreetMap data with pedestrian sidewalk information. Click here for further information.

It is worth to mention that similar experiments and researches have been done by the Geoinformatics laboratory at School of Information Sciences of University of Pittsburgh, where an algorithm has been defined and developed to construct pedestrian network data based on GPS traces. For more information please refer to:

Kasemsuppakorn, P., & Karimi, H. A. (2013). A pedestrian network construction algorithm based on multiple GPS tracesTransportation research part C: emerging technologies26, 285-300.

Geospatial analyses are increasingly being conducted in networked environments. In such cases, geographic analyses are carried out by leveraging ressources (including geospatial algorithms) on some remote server. A user might upload some dataset onto a server, triggers some geo-computation and awaits the results.

Most of such web-based geo-processing services are implementing the so called “Web Processing Service” (WPS) standard, which is provided by the OGC. This is an industry standard for serving access to geospatial processing capabilities. It allows performing analyses in two different ways, either in a synchronous mode or asynchronoulsy. The synchronous mode finishes all action within one request-response cycle. In such case, there is no need for further action at the user. The results are instantaneously responded once the processing is finished. However, it is obvious that this mode is not suitable for highly complex processing tasks. These can take up to several hours, almost certainly exceeding the common server time-out ranges (typically around 30s). This is where the second option, asynchronous processing, comes into play. In that case, the user triggers the desired computation and receives an URL. This URL references the location where the results will be stored upon completion. However, the user is not aware when this will happen. Thus, the user constantly has to check the URL for results, resulting into large network overheads when being performed in an automated way. This is particularly a problem when geographic analyses are included in some automated processing chain.

One way of overcoming this problem is the so called “web socket” technology. This technology is part of the HTML 5 initiative and enables servers for sending data to clients. Older approaches for this purpose have often misused HTTP by artifically keeping the connection open or emulating unfinished data transmission (e.g., like with long polling or iframe streaming). However, HTTP has been designed for unidirectional client-to-server communication. It is by no means suited for two-way communication. Thus, all these approaches are unstandardised, which leads to interoperability problems in case of service-oriented architectures. The web sockets technology overcomes these issues. It switches communication from HTTP to a self-standing protocol. This protocol has specifically been designed for communication in both directions.

We combine WPS and web sockets by extending the asynchronous mode of WPS. Once a client has triggered a computational task, a URL to a web socket server is responded. The client now has to listen to that server. Instead of constantly exchanging HTTP headers, the connection stays idle until it gets invoked by one of the two communication partners. Once the geoprocessing is done, WPS leverages web socket technology for sending a notification about process completion. The client receives this notification, containing a URL referencing the results. This approach enables integration of long-lasting geoprocessing tasks into automated processing chains and saves ressources at the client, the server and in the network. In the corresponding article (see below) we also present suggestions for how to alter the current WPS standard towards push-based communication like described above.

Reference

Westerholt, R. & Resch, B. (2014): Asynchronous Geospatial Processing: An Event-Driven Push-Based Architecture for the OGC Web Processing Service. Transactions in GIS, DOI: 10.1111/tgis.12104.

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