CIScience Heidelberg members Dr. Tobias Törnros and Dr. Hongchao Fan attended the ISSDQ’15 (The 9th International Symposium on Spatial Data Quality) from 28 to 30 September 2015 in La Grande Motte, France. Tobias had an excellent talk about uncertainties of completeness measures in OpenStreetMap – A case study for buildings in a medium-sized German city. On behalf of the special session chairs (Prof. Dr. Alexander Zipf, Dr. Jamal Jokar Arsanjani, Dr. Mohamed Bakillah, Dr. Vyron Antoniou and Ahmed Loai Ali), Hongchao Fan from GIScience HD chaired a special session on quality analysis of Volunteered Geographic Information (VGI) towards effective use.
Approximately, 60 participants took part in the ISSDQ’15. 31 oral presentations were given by colleagues from more than 10 countries. In addition, there was a poster session with 15 posters. During the two-days event, the symposium participants presented and discussed methods, algorithms, and applications related to spatial data quality. More information could be found on the symposium website: http://www.isprs-geospatialweek2015.org/workshops/issdq/program.html.
This year ISSDQ’15 is organized as part of the newly established ISPRS Geospatial Week 2015, a larger even grouping ISPRS and non-ISPRS conferences. The ISSDQ’15 was chaired by Ana-Maria Olteanu-Raimond (IGN-France), Cyril de-Runz (University of Reims-ChampagneArdenne, France) and Rodolphe Devillers (Memorial University of Newfoundland, Canada).
Törnros, T., Dorn, H., Hahmann, S., and Zipf, A. (2015): Uncertainties of completeness measures in OpenStreetMap - A Case Study for buildings in a medium-sized German city, ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., II-3/W5, 353-357, doi:10.5194/isprsannals-II-3-W5-353-2015
Detailed knowledge regarding the whereabouts of people and their social activities in urban areas with high spatial and temporal resolution is still widely unexplored. Thus, the spatiotemporal analysis of Location Based Social Networks (LBSN) has great potential regarding the ability to sense spatial processes and to gain knowledge about urban dynamics, especially with respect to collective human mobility behavior. The objective of a recently published paper in the international journal Computers, Environment and Urban Systems (CEUS) (available online) is to explore the semantic association between georeferenced tweets and their respective spatiotemporal whereabouts. We apply a semantic topic model classification and spatial autocorrelation analysis to detect tweets indicating specific human social activities. We correlated observed tweet patterns with official census data for the case study of London in order to underline the significance and reliability of Twitter data.The visualizationn below shows the observed work activity cluster pattern from tweets and their association with Census populations.
Our empirical results of semantic and spatiotemporal clustered tweets show an overall strong positive correlation in comparison with workplace population census data (see correlation plot), being a good indicator and representative proxy for analyzing workplace-based activities. The outcomes of this study may be considered in future research work regarding the inference and trustworthiness of human mobility patterns from crowdsourced data. Location inference of residential and workplace areas are a key factor of the given transportation demand. LBSN can help to better understand these processes and explore the impact of urban spatial structures on travel demand and human mobility as a future research direction.
Steiger, E. Westerholt, R., Resch, B. and Zipf, A. (2015): Twitter as an indicator for whereabouts of people? Correlating Twitter with UK census data. Computers, Environment and Urban Systems (CEUS). Elsevier. Volume 54, November 2015, Pages 255–265 .doi:10.1016/j.compenvurbsys.2015.09.007
Sep 26th, 2015 by Amin Mobasheri
During mid August and September, Amin Mobasheri had a short research visit to Institute of Mathematics and Computer Science (ICMC) at University of São Paulo, Brazil. Last week on 14th of September, he gave a presentation about “Open Geospatial Data Quality Assessment and Enrichment. The Case study of Routing and navigation services for people with limited mobility“.
This talk included assessment of OpenStreetMap data completeness; as one of the most successful examples of VGI in Europe, and the existing challenges regarding the fitness of use of this data in routing and navigation of mobility-impaired persons.
The visit led to fruitful discussions and solid plans for future collaboration on OpenStreetMap quality analysis between GIScience Heidelberg and AGORA group from ICMS.
Our paper titled “Explorative Public Transport Flow Analysis from Uncertain Social Media Data” in the GeoCrowd 2014 workshop of the ACM SIGSPATIAL conference has been selected by the workshop organizers as its best paper.
In this paper, we propose a framework to detect human mobility transportation hubs and infer public transport flows from unstructured georeferenced social media data using semantic topic modeling and spatial clustering techniques. An infrastructure for receiving and storing large sets of social media data has been developed together with an ad hoc processing framework in order to consider the high uncertainty of our retrieved data. Given the detected and extracted social media signals indicating human mobility, we compared the results with the public transport network from OpenStreetMap and classified observed mobility patterns for an exemplary case study. To analyze collected datasets a web based visualization tool has been setup.
Please click on the image to open the interactive WebGL
Our WebGL visualization at http://koenigstuhl.geog.uni-heidelberg.de/opentrafficflow/ shows increasing counts of network matched social media posts clustering outside London and moving into the center between 6-12 am and 6-12 pm. This typical commuting behavior can be detected along the whole railway network while posts between 12-6pm are spatially concentrated along the inner transportation network of London.
Steiger, E. Ellersiek, T. Zipf, A. (2014): Explorative public transport flow analysis from uncertain social media data. Third ACM SIGSPATIAL International Workshop on Crowdsourced and Volunteered Geographic Information (GEOCROWD) 2014. In conjunction with ACM SIGSPATIAL 2014. Dallas, TX, USA. dx.doi.org/10.1145/2676440.2676444
Benjamin (active Heidelberg disastermapper and GIScience group member) explains in this blog post how to create your own Missing Map like microtasking application using PyBossa
An example is the microtasking app he did set up to identify human settlements and roads in South Kivu for the missing maps project at
You can easily contribute to this Missing Maps task by spending just a little time helping to classify some aerial imagery only by telling whether there are human settlements or major roads in the satellite imagery.
Here you can see what has been accomplished so far:
Thanks for contributing!
Mid of August we started for our second field trip in the Canadian Arctic. This time the team consisted of Inga Beck, Sabrina Marx and Detlef May. As Sabrina already joined the trip in June, many things – such as customs, security etc. worked much easier than in June.
We only had very little time for our field work, as we only had 7 full days in Inuvik. So we hoped for pretty good weather conditions for (i) being able to fly into the camp with the helicopter, (ii) conducting all our measurements – especially the terrestrial Laser scanning – and (iii) flying out of the camp in time. The weather was really nasty when we arrived, but we kept being optimistic with our plans.
But everything was really successfully: We flew into the camp one day after we arrived in Inuvik, and started our measurements the other day. We were able to work three full days in the sun and accomplished all our tasks in time. This included the data capturing such as LiDAR and GNSS, the measurements of the frost table depth as well as the subsidence. We also measured the soil moisture at 7 sites and installed permanent soil moisture loggers at 4 depth.
Now we are looking forward to get first TanDEM-X data to start working on the InSAR analysis.
Sep 21st, 2015 by Maxim Rylov
In a previous blog post, we have imparted to our readers that OpenMapSurfer web map tile service is being used by several projects. Today, we want to provide an updated list of the users. Among them are e.g.:
If you are looking for a free, beautiful and readable map for your app or web site, then OpenMapSurfer’s maps is a good choice. Please do not hesitate to contact us.
Sep 20th, 2015 by Amin Mobasheri
The 27th International Cartographic Conference (ICC) was held from 23-28th of August in Rio de Janeiro, Brazil. The conference brought together several hundreds of professors, researchers and students worldwide in three main disciplines of Cartography, GIScience, and Remote Sensing to discuss various research topics ranging from map design, map use, users and usabilities to location based services, web GIS, SDI, standards and semantics as well as remote sensing applied to cartography and others.
Andreas Reimer and Amin Mobasheri from GIScience research group of Heidelberg University actively participated in the conference. Andreas presented three topics with his co-author entitled: “An algebraic notation for Bertin’s semiology with an extension for cartographic usage of the plane“, “A Formal Approach to the Automated Labelling of Groups of Features” and “Taxonomy Validation for Chorematic Diagrams“.
Amin Mobasheri also presented his paper entitled “Web Mapping of Geo-tagged Shipping Information; Case Study: The LLOYDS Lists” which presents the ongoing results of the research being conducted in the LLOYDS lists project. In addition, he presented a poster about “Visualizing Sidewalk Information for People with Limited Mobilities; Cartographic Challenges and Requirements” in order to exchange ideas about methods for visualizing the quality of OpenStreetMap data, related to his work in CAP4Access project.
Amin was one of the five research scholars who received the ICA research scholarship award from the International Cartographic Association in the year 2015.
Amin Mobasheri (middle) receiving the ICA research scholarship award from Georg Gartner (ICA president) and Laszlo Zentai (ICA treasurer) during the ICC
Sep 17th, 2015 by Rene Westerholt
In addition to our previously announced presentation, the GIScience group Heidelberg is also represented with a stand at the Intergeo. We present a variety of outcomes of our efforts from throughout the last years. These include, among others, spatial media analysis, OSM.3D and our highly recognized OpenRouteService or OpenMapSurfer.. Our stand is part of the joint appearance of the GeoNet.MRN, a regional initiative for strengthening the geoinformation industry and research in the Rhine-Neckar metropolitan area. You can still meet us in Hall 6 at stand D6.093 until 6pm today. We’re looking forward seeing you there!
GIScience HD Intergeo team
Sep 16th, 2015 by Bernhard Höfle
The Heidelberg University reports in a current press release (in German) about our new project 4DEMON: 4D Near Real-Time Environmental Monitoring, which is funded by the highly competitive Junior Professorship Funding Scheme of the Ministry of Science, Research and Arts, Baden-Wuerttemberg.