Abschlussarbeiten - Institut für Geoinformatik

Sketch maps are traditionally drawn on a flat sheet of paper. However, with accessible, consumer-grade Virtual Reality devices it is now very easy to put on a VR headset and "draw in the air". This might be particularly useful in situations where you want to communicate how the environment looks in the vertical. For instance, when you want to draw a path of drone flying above some landscape, or describe to another person how to navigate a multi-level shopping mall, or explain to a friend how to get out of a metro station near your home.

The goal of this thesis is to understand the potential of 3D sketch maps in VR as a tool for communicating spatial knowledge.

The thesis can be approached from two perspectives:

From the technological perspective it is possible to design new ways of drawing 3D sketch maps in Virtual Reality, and compare them to traditional paper sketch maps. It is also interesting to explore how complex 3D sketch maps can be analysed systematically and what tools can we design to support the analysis of such (sometimes very complex and very messy) 3D drawings.

From the research perspective it is necessary to conduct user experiments to understand whether people can make good use of this new possibility offered by VR, or do they always find it more intuitive to draw on paper. Also, it is important to identify contexts in which 3D sketch maps are necessary - perhaps for most navigational scenarios a sheet of paper is sufficient? If so, what are specific cases (aviation, complex buildings) where 3D sketch maps are necessary?

One straight-forward way to study this is to ask participants to play a VR game where vertical navigation is important (virtual scuba diving, submarine simulator, flying a star wars battleship, a drone, or a passanger plane, downhill skiing) and ask them to draw sketch maps based on this experience.

Kim, K. G., Krukar, J., Mavros, P., Zhao, J., Kiefer, P., Schwering, A., ... & Raubal, M. (2022). 3D Sketch Maps: Concept, Potential Benefits, and Challenges. In 15th International Conference on Spatial Information Theory (COSIT 2022) (Vol. 240, p. 14). Schloss Dagstuhl, Leibniz-Zentrum für Informatik.

Kontakt: Jakub Krukar

Earth Observation (EO) data cubes are multidimensional arrays of spatial and temporal data, crucial for monitoring and analyzing environmental changes. Machine learning (ML) models applied to EO data cubes enable advanced data analysis and predictive capabilities. However, the diversity of programming languages used in the spatial data science and geoinformatics community, particularly R and Python, poses challenges for interoperability and reproducibility of these ML models.

The outcomes of this research are expected to facilitate smoother integration and collaboration among spatial data scientists and geoinformatics professionals who rely on different programming environments, promoting the reproducibility and interoperability of EO data analysis projects. This work will contribute to the broader goal of advancing geospatial data science by bridging the gap between diverse computational ecosystems.

Use Case:

Carrying out spatial-temporal analysis, such as time-series crop classification in Germany, leveraging the ONNX interoperability format : https://onnx.ai/

Guiding Research Questions:

For Bachelor Thesis:

Model Portability: How can a deterministic machine learning model, such as Support Vector Machine (SVM), be trained on Earth Observation data cubes in Python and then ported to R using the ONNX format?
Performance Evaluation: What are the differences in performance and accuracy of the SVM model when ported from Python to R for time-series crop classification in Germany
Interoperability Challenges: What are the challenges and potential solutions in ensuring interoperability and reproducibility of machine learning models between Python and R programming environments using ONNX?

For Master’s Thesis:

What is the feasibility of implementing identical deep learning models for Earth Observation data cubes in R, Python, and Julia, and ensuring their interoperability?
How do the available tools and libraries for machine learning in R, Python, and Julia compare in terms of ease of use, performance, and integration with EO data cubes?
What are the differences in command structure and interface among R, Python, and Julia for machine learning tasks related to EO data cubes, and how do these differences impact the reproducibility and interoperability of the models?

These research questions aim to explore the practical aspects of implementing and ensuring interoperability of machine learning models across different programming languages, with a focus on spatial-temporal analysis and the specific application of time-series crop classification. The Master's thesis will particularly emphasize the use of deep learning frameworks TensorFlow and PyTorch.

Please contact:
Brian Pondi brian.pondi@uni-muenster.de
and
Edzer Pebesma edzer.pebesma@uni-muenster.de

Kontakt: Brian Pondi

In den letzten Jahren hat die Verbreitung erfundener oder völlig falscher Informationen stark zugenommen (z. B. Verschwörungstheorien, Behauptungen ohne Grundlage, erfundene Ereignisse). Die breite Verfügbarkeit von generativer KI wird diesen Trend höchstwahrscheinlich nicht nur verstärken, sondern auch die Erkennung gefälschter Informationen erheblich erschweren.

Die Idee hinter diesem Thema ist es, Wege zu erforschen, wie Standortinformationen strategisch genutzt werden können, um ortsbezogene Informationen zu verifizieren. Viele Informationen haben einen direkten Bezug zu einem realen Ort, z. B. Fotos (oder generierte Bilder), die an einem bestimmten Ort aufgenommen wurden (oder von denen behauptet wird, dass sie an diesem Ort aufgenommen wurden).

Dieser Standort kann genutzt werden, um den Wahrheitsgehalt der Informationen oder Medien auf verschiedene Weise zu überprüfen. Ein Ansatz könnte darin bestehen, vertrauenswürdige kartografische Informationen zu verwenden, um Bildinhalte oder Textbeschreibungen mit Informationen aus einer Karte zu vergleichen. Ein zweiter Ansatz könnte sich mit der Überprüfung von Fakten vor Ort befassen, z. B. über einen standortbasierten Dienst, der Faktenprüfer*innen dorthin führt, wo sie den Wahrheitsgehalt bestimmter Informationen anhand eines bestimmten Protokolls bewerten können. Dieses Protokoll sollte sicherstellen, dass sie stichhaltige Beweise für den Wahrheitsgehalt zu prüfender Informationen liefern können (z. B. über AR-basierte vergleichende Overlays). Ein dritter Ansatz könnte Möglichkeiten zur Nutzung von Standort-Sensordaten (GPS, Kompass, Kreisel, Zeitstempel) untersuchen, um eine Blockchain für Fotos zu erstellen, die an einem bestimmten Ort aufgenommen wurden. Auf diese Weise könnten Einzelpersonen vertrauenswürdige Informationen erstellen und andere die Informationen überprüfen. Schließlich ist die Verwendung zuverlässiger historischer Standortinformationen (Karten, Fotos, Datensätze) zur Bewertung des Wahrheitsgehalts neu eingestellter Informationen ein weiterer Ansatz, den es sich zu untersuchen lohnt. Bei allen Ansätzen wäre es wichtig, potenzielle Angriffe zu untersuchen (insbesondere solche, die durch Prompt-Engineering für aktuelle LLMs oder die Koordination zwischen böswilligen Personen vor Ort entstehen).

Jeder dieser Ansätze kann zum Thema einer Abschlussarbeit werden. Im Prinzip könnten diese Themen entweder als Masterarbeit oder als Bachelorarbeit bearbeitet werden. Sie erfordern jedoch eine gründliche Hintergrundforschung und können technisch anspruchsvoll sein. Wenn Sie sich für dieses allgemeine Thema interessieren, bitte an Chris Kray wenden.

Kontakt: Christian Kray

Perceived Spaciousness is the subjective feeling of how large a given space is. Just think about the difference between the seminar room 242 vs. the atrium in the centre of the GEO1 building. Does the atrium feel 5x larger? 10x larger? 20x larger? Or imagine walking through a small entrance into a large temple. How much volume does it need to have to create the feeling of "wow, this is huge!" ?

Resaerch has shown that people have very distorted way of judging this and that the volume of space alone (the amount of "empty air" surrounding you) is not the only important factor. It matters what shape this empty space has (is it taller or longer?), where you are currently standing (above or below the open space? close to the wall or in its centre?), and where you entered it from (entering into a large room from a small one vs a small one from a large one).

The goal of this thesis is to understand what affects our peceived spaciousness. The thesis can approached from two perspectives.

From the technological perspective it is necessary to create new ways of studying perceived spaciousness in Virtual Reality. Researchers used various ways to ask people "how spacious does this space feel right now?" - they asked them verbally to rank it from 1 to 7, or gave them a circular dial that participants rotated when they felt more spacious. VR opens the chance to create better ways to gather this kind of data.

From the research perspective VR offers us the chance to design architectural experiments impossible in real life. For instance, we can move a person from a very small space to an extremely spacious one in a matter of seconds, and test their reactions. We can change their pathway (e.g., reverse it so that they move from a large space to a small one) and see if the reaction is symmetric. We can also systematically modify the Virtual Reality rooms by changing their shape, size, or lighting, and test how these changes affect perceived spaciousness.

Krukar, J., Manivannan, C., Bhatt, M., & Schultz, C. (2021). Embodied 3D isovists: A method to model the visual perception of space. Environment and Planning B: Urban Analytics and City Science, 48(8), 2307-2325.

Kontakt: Jakub Krukar

In order to benefit from location-based services (LBS) such as navigation support, local recommender systems or delivery services, users need to share their location with the service provider. This can have negative implications for their privacy as the service provider might learn a lot about users, e.g. movement patterns, places they frequent and inferred knowledge such as health conditions.

At the same time, service provision would also be possible if users did not share their precise location: a weather forecast app, for example, might work well enough with very coarse-grained location information. For some LBS, having access to lower-quality location information might be problematic. For example, providing turn-by-turn instructions might be impossilbe if users share coarse-grained location information.

The goal of this topic is thus to develop and evaluate approaches for different types of LBS to adapt to different levels of quality of location information. The topic can be tackled from different perspectives and therefore can serve as a starting point for several different theses projects:

on the algorithmic level, an analysis of common algorithms used in LBS to provide certain services (such as routing) can be carried out to develop and evaluate new/improved algorithms that can better cope with different levels of location quality
on the infrastructure level, different frameworks and libraries for the development of LBS can be analysed regarding how well they support copting with different levels of location quality; this can then inform the design and evaluation of an improved solution
on the visualisation/user interface level, an analysis of exsting solutions to convey instructions/information to users in LBS can be carried out with respect to how well they work when provided with location information of lower quality; this can then inform the design and evaluation of improved, adaptive visualsations and user interfaces

Students interested in this topic area can have a look at the SIMPORT project and the publications listed below:

Linking location privacy, digital sovereignty and location-based services: a meta review. (2023) S Özdal Oktay, S Heitmann, C Kray. Journal of Location Based Services, 1-52.
‘Informed’consent in popular location based services and digital sovereignty. (2022) J Dreyer, S Heitmann, F Erdmann, G Bauer, C Kray. Journal of Location Based Services 16 (4), 312-342.
Ranasinghe, C., Schiestel, N., & Kray, C. (2019, October). Visualising location uncertainty to support navigation under degraded gps signals: A comparison study. In Proceedings of the 21st International Conference on Human-Computer Interaction with Mobile Devices and Services (pp. 1-11).
Ranasinghe, C., Heitmann, S., Hamzin, A., Pfeiffer, M., & Kray, C. (2018, December). Pedestrian navigation and GPS deteriorations: User behavior and adaptation strategies. In Proceedings of the 30th Australian Conference on Computer-Human Interaction (pp. 266-277).
Ranasinghe, C., & Kray, C. (2018). Location information quality: A review. Sensors, 18(11), 3999.

Kontakt: Christian Kray

Sketch maps are traditionally drawn on a flat sheet of paper. However, with accessible, consumer-grade Virtual Reality devices it is now very easy to put on a VR headset and "draw in the air". This might be particularly useful in situations where you want to communicate how the environment looks in the vertical. For instance, when you want to draw a path of drone flying above some landscape, or describe to another person how to navigate a multi-level shopping mall, or explain to a friend how to get out of a metro station near your home.

The goal of this thesis is to understand the potential of 3D sketch maps in VR as a tool for communicating spatial knowledge.

The thesis can be approached from two perspectives:

From the technological perspective it is possible to design new ways of drawing 3D sketch maps in Virtual Reality, and compare them to traditional paper sketch maps. It is also interesting to explore how complex 3D sketch maps can be analysed systematically and what tools can we design to support the analysis of such (sometimes very complex and very messy) 3D drawings.

From the research perspective it is necessary to conduct user experiments to understand whether people can make good use of this new possibility offered by VR, or do they always find it more intuitive to draw on paper. Also, it is important to identify contexts in which 3D sketch maps are necessary - perhaps for most navigational scenarios a sheet of paper is sufficient? If so, what are specific cases (aviation, complex buildings) where 3D sketch maps are necessary?

One straight-forward way to study this is to ask participants to play a VR game where vertical navigation is important (virtual scuba diving, submarine simulator, flying a star wars battleship, a drone, or a passanger plane, downhill skiing) and ask them to draw sketch maps based on this experience.

Kim, K. G., Krukar, J., Mavros, P., Zhao, J., Kiefer, P., Schwering, A., ... & Raubal, M. (2022). 3D Sketch Maps: Concept, Potential Benefits, and Challenges. In 15th International Conference on Spatial Information Theory (COSIT 2022) (Vol. 240, p. 14). Schloss Dagstuhl, Leibniz-Zentrum für Informatik.

Kontakt: Jakub Krukar

Earth Observation (EO) data cubes are multidimensional arrays of spatial and temporal data, crucial for monitoring and analyzing environmental changes. Machine learning (ML) models applied to EO data cubes enable advanced data analysis and predictive capabilities. However, the diversity of programming languages used in the spatial data science and geoinformatics community, particularly R and Python, poses challenges for interoperability and reproducibility of these ML models.

The outcomes of this research are expected to facilitate smoother integration and collaboration among spatial data scientists and geoinformatics professionals who rely on different programming environments, promoting the reproducibility and interoperability of EO data analysis projects. This work will contribute to the broader goal of advancing geospatial data science by bridging the gap between diverse computational ecosystems.

Use Case:

Carrying out spatial-temporal analysis, such as time-series crop classification in Germany, leveraging the ONNX interoperability format : https://onnx.ai/

Guiding Research Questions:

For Bachelor Thesis:

Model Portability: How can a deterministic machine learning model, such as Support Vector Machine (SVM), be trained on Earth Observation data cubes in Python and then ported to R using the ONNX format?
Performance Evaluation: What are the differences in performance and accuracy of the SVM model when ported from Python to R for time-series crop classification in Germany
Interoperability Challenges: What are the challenges and potential solutions in ensuring interoperability and reproducibility of machine learning models between Python and R programming environments using ONNX?

For Master’s Thesis:

What is the feasibility of implementing identical deep learning models for Earth Observation data cubes in R, Python, and Julia, and ensuring their interoperability?
How do the available tools and libraries for machine learning in R, Python, and Julia compare in terms of ease of use, performance, and integration with EO data cubes?
What are the differences in command structure and interface among R, Python, and Julia for machine learning tasks related to EO data cubes, and how do these differences impact the reproducibility and interoperability of the models?

These research questions aim to explore the practical aspects of implementing and ensuring interoperability of machine learning models across different programming languages, with a focus on spatial-temporal analysis and the specific application of time-series crop classification. The Master's thesis will particularly emphasize the use of deep learning frameworks TensorFlow and PyTorch.

Please contact:
Brian Pondi brian.pondi@uni-muenster.de
and
Edzer Pebesma edzer.pebesma@uni-muenster.de

Kontakt: Brian Pondi

Recent years have seen a sharp increase in fabricated or outright false information being widely distributed (e.g. conspiracy theories, base-less claims, invented events). The broad availability of generative AI will most likely not only strengthen this trend but make it much harder to recognise fabricated information.

The idea behind this topic is to investigate ways to use location information strategically to verify the truthfulness of shared information. A large percentage of all information has a direct link to a real-world location, for example, photographs (or generated images) taken at a particular place (or claimed to be taken at that location).

This location in turn can be used to check the truthfulness of the information or media in different ways. One approach could be to use trustworthy cartographic information to compare image contents or textual descriptions to information from a map. A second approach could look into checking facts on site, e.g. via a location-based service that directs fact-checkers to where they can assess the truthfulness of some information by following a particular protocol that ensures they can provide strong evidence (e.g. via AR-based comparative overlays). A third approach could investigate ways to use location-sensor data (GPS, compass, gyro, timestamps) to create a blockchain for photos taken a particular location. This could provide a way for individual to create trustworthy information and for others to verify information. Finally, using reliable historical location information (maps, photos, datasets) to assess the truthfulness of newly posted information is another approach worthwhile investigating. For all different approaches, looking into potential attacks (particularly those presented by prompt engineering for current LLMs or coordination between malicious people on site) would be important.

Either of these approaches can become a thesis topics. In principle, these topics could be done either as Master thesis or a Bachelor thesis. However, they will require thorough background research and can potentially be technically demanding. If you are interested in this general topic area or one of the listed examples, please get in touch with Chris.

Kontakt: Christian Kray

Simulating Fine-Scale Population Flows for Infectious Disease Transmission Models Using Multi-Source Datasets Understanding human movement patterns is crucial for identifying the transmission patterns of infectious diseases, as the spread of such diseases between geographical regions is largely influenced by human activities. However, obtaining data on population flow, which is essential for this understanding, is challenging due to privacy concerns.

There are very few datasets available that offer insights into human movement patterns, and those that do come with limited sample sizes. For example, the GeoLife dataset (Zheng et al., 2010) comprises GPS trajectory data collected over three years from 178 users as part of the GeoLife project by Microsoft Research Asia. Similarly, the NCCU Trace (Tsai and Chan, 2015) records the

movements of 115 students within the campus of National Chengchi University in Taiwan over a period of 15 days, capturing GPS, WiFi, and Bluetooth device information. Moreover, it's important to note that these datasets were not collected specifically in the context of disease transmission scenarios. Individual-level trajectories are important for detailed analysis but are computationally challenging to generate. Additionally, correlating these detailed datasets with other relevant data, such as disease infection rates, can be difficult because such infection datasets are typically available in aggregated form at higher spatial resolutions.

In this thesis, the aim is to simulate mass flow of population at finer scale using available datasets such as gridded datasets depicting daily and hourly human activities (from Mapbox1), origin-destination matrices (Spain2 or England and Wales3), land-use/land-cover datasets, and road connection networks. The applicability of these simulated flows will be explored in understanding

disease transmission, considering various scenarios including restricted movement periods and different levels of disease consciousness among the population. Once the population flow is simulated, the focus of the research can be further extended to identifying potential contact points within the population flow where disease transmission could occur.

Links

1. https://docs.mapbox.com/data/movement/guides/activity-index/

2. https://www.transportes.gob.es/ministerio/proyectos-singulares/estudios-de-movilidad-con-big-data/metodologia-del-estudio-de-movilidad-con-bigdata

3. https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/

populationestimates/bulletins/origindestinationdataenglandandwales/census202

References

Tsai, T. C., & Chan, H. H. (2015). NCCU Trace: Social-network-aware mobility trace. IEEE

Communications Magazine, 53(10), 144-149.

Zheng, Y., Xie, X., & Ma, W. Y. (2010). GeoLife: A collaborative social networking service among

user, location and trajectory. IEEE Data Eng. Bull., 33(2), 32-39.

Kontakt: Poshan Niraula, Edzer Pebesma

Perceived Spaciousness is the subjective feeling of how large a given space is. Just think about the difference between the seminar room 242 vs. the atrium in the centre of the GEO1 building. Does the atrium feel 5x larger? 10x larger? 20x larger? Or imagine walking through a small entrance into a large temple. How much volume does it need to have to create the feeling of "wow, this is huge!" ?

Resaerch has shown that people have very distorted way of judging this and that the volume of space alone (the amount of "empty air" surrounding you) is not the only important factor. It matters what shape this empty space has (is it taller or longer?), where you are currently standing (above or below the open space? close to the wall or in its centre?), and where you entered it from (entering into a large room from a small one vs a small one from a large one).

The goal of this thesis is to understand what affects our peceived spaciousness. The thesis can approached from two perspectives.

From the technological perspective it is necessary to create new ways of studying perceived spaciousness in Virtual Reality. Researchers used various ways to ask people "how spacious does this space feel right now?" - they asked them verbally to rank it from 1 to 7, or gave them a circular dial that participants rotated when they felt more spacious. VR opens the chance to create better ways to gather this kind of data.

From the research perspective VR offers us the chance to design architectural experiments impossible in real life. For instance, we can move a person from a very small space to an extremely spacious one in a matter of seconds, and test their reactions. We can change their pathway (e.g., reverse it so that they move from a large space to a small one) and see if the reaction is symmetric. We can also systematically modify the Virtual Reality rooms by changing their shape, size, or lighting, and test how these changes affect perceived spaciousness.

Krukar, J., Manivannan, C., Bhatt, M., & Schultz, C. (2021). Embodied 3D isovists: A method to model the visual perception of space. Environment and Planning B: Urban Analytics and City Science, 48(8), 2307-2325.

Kontakt: Jakub Krukar

In order to benefit from location-based services (LBS) such as navigation support, local recommender systems or delivery services, users need to share their location with the service provider. This can have negative implications for their privacy as the service provider might learn a lot about users, e.g. movement patterns, places they frequent and inferred knowledge such as health conditions.

At the same time, service provision would also be possible if users did not share their precise location: a weather forecast app, for example, might work well enough with very coarse-grained location information. For some LBS, having access to lower-quality location information might be problematic. For example, providing turn-by-turn instructions might be impossilbe if users share coarse-grained location information.

The goal of this topic is thus to develop and evaluate approaches for different types of LBS to adapt to different levels of quality of location information. The topic can be tackled from different perspectives and therefore can serve as a starting point for several different theses projects:

on the algorithmic level, an analysis of common algorithms used in LBS to provide certain services (such as routing) can be carried out to develop and evaluate new/improved algorithms that can better cope with different levels of location quality
on the infrastructure level, different frameworks and libraries for the development of LBS can be analysed regarding how well they support copting with different levels of location quality; this can then inform the design and evaluation of an improved solution
on the visualisation/user interface level, an analysis of exsting solutions to convey instructions/information to users in LBS can be carried out with respect to how well they work when provided with location information of lower quality; this can then inform the design and evaluation of improved, adaptive visualsations and user interfaces

Students interested in this topic area can have a look at the SIMPORT project and the publications listed below:

Linking location privacy, digital sovereignty and location-based services: a meta review. (2023) S Özdal Oktay, S Heitmann, C Kray. Journal of Location Based Services, 1-52.
‘Informed’consent in popular location based services and digital sovereignty. (2022) J Dreyer, S Heitmann, F Erdmann, G Bauer, C Kray. Journal of Location Based Services 16 (4), 312-342.
Ranasinghe, C., Schiestel, N., & Kray, C. (2019, October). Visualising location uncertainty to support navigation under degraded gps signals: A comparison study. In Proceedings of the 21st International Conference on Human-Computer Interaction with Mobile Devices and Services (pp. 1-11).
Ranasinghe, C., Heitmann, S., Hamzin, A., Pfeiffer, M., & Kray, C. (2018, December). Pedestrian navigation and GPS deteriorations: User behavior and adaptation strategies. In Proceedings of the 30th Australian Conference on Computer-Human Interaction (pp. 266-277).
Ranasinghe, C., & Kray, C. (2018). Location information quality: A review. Sensors, 18(11), 3999.

Kontakt: Christian Kray

External Thesis in co-operation with con terra. A PDF file with all information can be downloaded here.

Usability is an important aspect of modern software quality. In recent years, the users’ expectations of user interfaces raised significantly. Within the last 2 decades, a large body of research thus focused on optimizing the usability of desktop and mobile applications, e.g., [1]. However, despite the general popularity of this topic, the usability of GIS software appears to have gained less interest—some examples are [2, 3].

As con terra is a leading provider for integrated Geo IT solutions on an international level, it seeks to optimize the quality of its products and solutions with a high degree of usability. Usually, GIS software products are complex systems, comprising many intertwining components. Thus, optimizing the usability of such complex systems is usually only manageable by focusing on each component individually. One particular component, which is used in basically every GIS software, is the “feature info”—a component, that provides additional background information to the contents visualized on a map. Figure 1 shows an example of a typical feature info.

Though feature infos are important components of practically every GIS software, the concept has not significantly changed within the last years. Yet, the characteristics of conventional feature infos may not suit, e.g., the requirements of mobile applications, which have gained a significant importance and presence in our everyday lives nowadays. One issue, for instance, may be the very limited screen real estate available on such small devices.

Moreover, in some application scenarios, the background information shown in a feature info may be significantly more complex than in the example shown above. For example, it may be necessary to provide data with a specific temporal extent, such as climate measurements. This thesis thus seeks to find novel approaches to visualize additional background information to users of GIS software. For example, the thesis could analyze the performance of three options to position the additional information, i.e., “in place attached”, “in place detached”, or “isolated” (e.g., showing information in a separate browser window or on another device).

http://www.ostkamp.de/forschung/FeatureInfo.pdf

Contact

Dr. Morin Ostkamp

con terra GmbH

Martin-Luther-King-Weg 24

48155 Münster 48149 Münster

+49 89 207 005 2200

m.ostkamp@conterra.de

Prof. Dr. Christian Kray

Institute for Geoinformatics

Heisenbergstraße 2

+49 251 83 33073

c.kray@uni-muenster.de

Literature

[1] Jakob Nielsen. Usability Engineering. Kaufmann, 1993

[2] Clare Davies and David Medyckyj-Scott. Gis usability: recommendations based on the user’s view. International Journal of Geographical Information Science, 8(2):175–189, 1994.

[3] Max J Egenhofer and James R Richards. Exploratory access to geographic data based on the map-overlay metaphor. Journal of Visual Languages & Computing, 4(2):105–125, 1993.

Autor: Yevgeniya Litvinova
Betreuer: Christian Kray

A major task in environmental science is to obtain spatially comprehensive data from limited field samples (e.g. climate stations, soil profiles, vegetation records,...). This is often done using machine learning algorithms that learn the relationships between field data and remotely sensed predictor variables (e.g. from satellites). The developed model is then used to make spatial predictions for the entire area of interest (i.e. create a "map" of the variable of interest).
Such a map is only valuable when the error of the model is known. The error assessment however causes major difficulties for models with spatial dependencies and cause standard validation methods to fail. There is increasing consent in literature that spatial validation is necessary and several strategies have been proposed (e.g. Roberts 2018, Meyer 2018, Valavi 2018, Brenning 2012). However, little research is done on how different strategies compare, which however is important to know for model comparisons and for finding the "right" validation strategy for a dataset.
This project aims at comparing and (as far as possible) evaluating different validation strategies for machine learning based spatial mapping of environmental variables. Usually in most projects the "true" performance is hard to assess due to the fact that the reference data are limited. Therefore we want to adress the problem using reference data that are available in a spatially continuous way hence providing a continuous reference. Such data are rare but a possible research task would be available in the field of rainfall monitoring: The RADOLAN dataset contains high quality rainfall data from a radar network in 1km spatial resolution and serves as an excellent reference set. We then want to model rainfall for Germany using data from the the geostationary satellite sensor MSG SEVIRI and auxiliary predictor variables such as elevation (see Kühnlein 2014 for the idea of mdoelling rainfall based on MSG SEVIRI).
Using the RADOLAN data we simulate different sampling designs (hence we simulate raingauges in different constellations: random, clustered,...) and train machine learning models to predict rainfall from MSG SEVIRI in a spatial way. Different strategies for spatial model evaluation are then compared.

Requirements:

R programming is an advantage, interest in working with machine learning algorithms

References:

Brenning, A. (2012): Spatial cross-validation and bootstrap for the assessment of prediction rules in remote sensing: The R package sperrorest. IEEE International Geoscience and Remote Sensing Symposium.

Kühnlein, M., T. Appelhans, B. Thies, and T. Nauss, 2014: Precipitation Estimates from MSG SEVIRI Daytime, Nighttime, and Twilight Data with Random Forests. Journal of Applied Meteorology and Climatology, 53 (11), 2457–2480.

Meyer, H., Reudenbach, C., Hengl, T., Katurji, M., Nauss, T. (2018): Improving performance of spatio-temporal machine learning models using forward feature selection and target-oriented validation. Environmental Modelling & Software 101: 1-9.

Roberts, D. R., V. Bahn, S. Ciuti, M. S. Boyce, J. Elith, G. Guillera-Arroita, S. Hauenstein, J. J. Lahoz-Monfort, B. Schröder, W. Thuiller, D. I. Warton, B. A. Wintle, F. Hartig, and C. F. Dormann, 2017: Cross-validation strategies for data with temporal, spatial, hierarchical, or phylogenetic structure. Ecography, doi:10.1111/ecog.02881.

Valavi R, Elith J, Lahoz‐Monfort JJ, Guillera‐Arroita G. blockCV: An r package for generating spatially or environmentally separated folds for k‐fold cross‐validation of species distribution models. Methods Ecol Evol. 2018;00:1–8. https://doi.org/10.1111/2041-210X.13107

Autor: Marc Dragunski
Betreuer: Hanna Meyer

Climate change-driven shifts in streamflow timing have been documented for Western North America and are expected to continue with increased warming. These changes will likely have the greatest implications on already short and overcommitted water supplies in the region. This study investigated changes in Western North American streamflow timing over the 1948 – 2008 period, including the very recent warm decade not previously considered, through a) trends in streamflow timing measures b) two second order linear models applied simultaneously over the region to test for the acceleration of these changes, and c) changes in runoff regimes. Basins were categorized by the percentage of snowmelt derived runoff to enable the comparison of groups of streams with similar runoff characteristics and to quantify shifts in snowmelt-dominated regimes.

Results indicate that streamflow has continued to shift to earlier in the water year, most notably for those basins with the largest snowmelt runoff component. However, an acceleration of these streamflow timing changes for the recent warm decades is not clearly indicated. Most coastal rain-dominated and some interior basins have experienced later timing. The timing changes are connected to area-wide warmer temperatures, especially in March and January, and precipitation shifts that bear sub-regional signatures. Notably, a set of the most vulnerable basins has experienced runoff regime changes, such that basins that were snowmelt dominated at the beginning of the observational period shifted to mostly rain dominated in later years. These most vulnerable regions for regime shifts are in the California Sierra Nevada, eastern Washington, Idaho, and north-eastern New Mexico. Snowmelt regime changes may indicate that the time available for adaptation of water supply systems to climatic changes in vulnerable regions are shorter than previously recognized.

Autor: Holger Fritze
Betreuer: Edzer Pebesma

Land use change is the result of complex interactions between socio-economic and environmental processes. Land use change models are used to simulate potential pathways in a land use system, aiding decision makers to develop effective policies. Because these policies can have large environmental, economic and social impacts, it is important to clearly understand the working of land use change models.

Sensitivity analysis (SA) is a method to assess how the variation in the output of a model can be related to different sources of variation in the model structure, input data and parameter values. This is key information to, for example, prioritize additional data collection for one of the model inputs. While SA can be very straightforward and is recognized as a key step in environmental modelling, it is more often than not omitted in environmental model evaluation exercises (Shin et al., 2013). For land use change models, SA has almost never been applied.

The aim of this BSc thesis is to perform a sensitivity analysis for the land use change model PLUC, for a case study in Brazil or Mozambique (Verstegen et al., 2012). The code of the land use change model (in python) will be provided. Depending on the interests of the student, the analysis can have a further focus on comparing two different SA methods (see Shin et al., 2013 for an overview of methods), on the dependence of the sensitivities on selected parameter ranges, on sensitivities at different spatial scales, on visualization methods for sensitivities, or an own idea.

References:

Shin, Guillaume, Croke and Jakeman, 2013, Addressing ten questions about conceptual rainfall–runoff models with global sensitivity analyses in R. Journal of Hydrology 503, 135-152.

Verstegen, Karssenberg, Van der Hilst and Faaij, 2012, Spatio-temporal uncertainty in Spatial Decision Support Systems: A case study of changing land availability for bioenergy crops in Mozambique. Computers, Environment and Urban Systems 36, 30-42.

Autor: Max Höltgen
Betreuer: Judith Verstegen
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43 Millionen Personenkraftwagen nehmen am Straßenverkehr in Deutschland teil, wovon 95% auf fossile Brennstoffe angewiesen sind [BMU 2010][KBA 2013]. Das starke Verkehrsaufkommen, vor allem in Städten, hat negative Folgen für die Umwelt und die Gesundheit der dort lebenden Menschen. So hatte im Jahr 2004 allein in Deutschland der Straßenverkehr einen Anteil von 20% am Gesamtvolumen der direkten CO2-Emissionen [BMU 2008]. Im Vergleich zum Jahr 2000 ist der Kraftfahrzeugbestand in Deutschland um 13,2% angestiegen. Während die Verkehrsinfrastruktur im überörtlichen Bereich bei Kreisstraßen und Autobahnen nur geringe Zunahmen, bei Bundesstraßen sogar Verluste erzielt [DeSTATIS 2012a][DeSTATIS 2012b]. Die Verluste bei Bundesstraßen und Zugewinne bei Kreisstraßen sind meist auf regionale Änderungen der Verkehrsinfrastruktur zurückzuführen. So können Bundesstraßen beispielsweise zu Kreisstraßen umstrukturiert werden [DBT 2013]. Innerorts sind größtenteils nur durch die Erschließung neuer Wohn- und Gewerbegebiete Zuwächse der Verkehrsinfrastruktur zu beobachten [ADAC 2008]. Eine zusätzliche Belastung für die Verkehrswege ist die steigende Fahrleistung der Personenkraftfahrzeuge. Diese betrug im Jahr 2011 schätzungsweise 610 Milliarden Kilometer [DIW 2012]. Dies belastet vor allem innerörtliche Verkehrswege, welche Aufgrund der umliegenden Bebauung nicht weiter ausgebaut werden können. Zunehmenden Einfluss erhalten daher Maßnahmen zur Veränderung des Verkehrsverhaltens, beispielsweise durch Einsatz von Umweltzonen oder Geschwindigkeitsbegrenzungen, um den Verkehrsfluss zu optimieren.

Um Prognosen und Verkehrsplanungen durchführen zu können, bedarf es einer zuverlässigen Erhebung von Informationen zum Straßenverkehr in Deutschland. Hierzu gibt das Bundesministerium für Verkehr, Bau und Stadtentwicklung das sogenannte deutsche Mobilitätspanel in Auftrag. Es finden seit 1994 jährlich und in dreijähriger Begleitung, Befragungen von knapp 2000 Personen zu ihrem Verkehrsverhalten statt. Unter anderem werden Informationen über die Länge der Wegstrecken sowie Kosten und Kraftstoffverbrauch, erhoben [DIW 2012]. Anhand dieser Erhebung kann nicht nur die Fahrleistung in Kilometern geschätzt werden, sondern auch der durchschnittliche und gesamte Kraftstoffverbrauch und die Schadstoffemission der Fahrzeuge. Der Gesamtverbrauch an Kraftstoff wird ebenfalls aus dem an den Tankstellen abgesetzten Volumen Kraftstoffe, sowie auf Grundlage von Verbrauchsangaben der Fahrzeughersteller und Automobilzeitschriften geschätzt [DIW 2004].

Gerade der Energie- und Kraftstoffverbrauch ist wichtig für die Berechnung der CO2-Emissionen und bilden eine weitere Informationsgrundlage zur Alltagsmobilität für die Stadt- und Verkehrsplanung. Die langfristigen Ziele in der Umweltpolitik sind daher, eine Senkung der CO2- und Schadstoffemissionen und einen geringeren Ressourcenverbrauch im Personenkraftverkehr zu erreichen. In vielen städtischen Bereichen werden daher Monitoringsysteme zur Überwachung der Luftqualität oder der Verkehrsstärke eingesetzt, um regelmäßig wichtige Umweltinformationen erfassen, die als Grundlage umweltpolitischer Entscheidungen dienen. An diesem Punkt setzt das EnviroCar-Projekt an.

Autor: Julius Wittkopp
Betreuer: Prof. Dr. Edzer Pebesma
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Fotoalben im Internet stellen eine beliebte Anwendung des Web 2.0 dar, bei der eine Vielzahl digitaler Fotos veröffentlicht wird. Zusätzlich zu den Bildern werden Metadaten wie Schlagwörter oder Freitextbeschreibungen gespeichert. Diese ermöglichen, Fotos zu kategorisieren und für textbasierte Suchmaschinen zu indizieren. Aus den Metadaten können ebenfalls Einträge für geographische Namenslexika gewonnen werden. In diesem Fall spricht man auch von sogenannten Bottom-Up Gazetteers (vgl. Keßler et al. 2009b). Zum Beispiel können die räumlichen Koordinaten aller Fotos mit der Bezeichnung „Münster“ zu einer Punktwolke zusammengefasst werden. Anschließend lassen sich daraus Aussagen über die geometrische Form und die geographi-sche Lage des Ortes ableiten.

Die vorliegende Arbeit betrachtet die zeitliche Dimension von Fotos. Es wird dabei untersucht, ob sich mithilfe der Aufnahmedaten die Dauer von Ereignissen ermitteln lässt. Hierbei werden Veranstaltungen (engl. Events) als eine bestimmte Ausprägung eines Ereignisses fokussiert. Deren Analyse erfolgt mit einem Clustering-Algorithmus, einer gängigen Klassifikationsmethode in der Geoinformatik. Das Verfahren wird anhand fünf ausgewählter Beispiele für Events und vergleichend mit drei Beispielen für Orte getestet.

Zur Visualisierung des Datenmaterials wurde eine graphische Benutzerschnittstelle in Form einer interaktiven Karte implementiert. Diese kann nun mit existierenden Gazetteers verbunden werden. Die Anwendung wurde speziell für Smartphones entwickelt, die sich in den letzten Jahren zunehmender Popularität erfreuen. Aufbauend auf den Ergebnissen der Analyse und der Implementierung werden mögliche Einsatzgebiete und Erweiterungen in Aussicht gestellt.

In dem ersten Kapitel werden zunächst alle für die weiteren Abschnitte notwendigen Grundlagen eingeführt.

Autor: Raimund Schnürer
Betreuer: Prof. Dr. Werner Kuhn
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Providing cognitively effective wayfinding instructions is an ongoing research objective. In addition to providing instructions that are efficient to reach a target location, research has also addressed developing instructions in a verbal format that could potentially facilitate spatial orientation and cognitive mapping. In this study, a type of verbal instructions is used that consists of not only essential information for a person to change the direction at decision points, but also additional orientation information along a route that is considered crucial for maintaining spatial orientation and getting an internal representation of the spatial layout. This type of verbal route descriptions is compared with machine-generated as well as skeletal descriptions for the same route. Thirty participants were randomly assigned to familiarize with one of three different types of wayfinding instructions, which described a specific route participants were unfamiliar with. Thus, they were intended to mentally walk along this route. The different types of instructions include: 1) machine-generated instructions, 2) orientationbased instructions, and 3) skeletal instructions. Results indicate that participants using the orientation instructions made least errors in their performance of spatial orientation. Results concerning their drawn sketch maps, however, revealed least accurate results in both landmark placement and route segment analysis among the three types of instructions. Regarding their good performance in orientation estimation, sketch map accuracy is suggested to be secondary concerning performance in spatial orientation and cognitive mapping. Additionally, using the orientation-based instructions type is not found beneficial regarding distance estimation accuracy. The machine-generated instructions with included distance information, however, are not found to lead to a good estimation of distance along the route. This study supports the validity of designing wayfinding instructions in the suggested way. It further implies the necessity to conduct a more comprehensive study on the effects of different types of instructions on various aspects of wayfinding behavior.

Autor: Stefan Fuest
Betreuer: Dr. Rui Li
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Our navigation is primarily driven by the visual sense. With some exceptions, our architectural and urban environment is designed with this principle in mind: money spent on placement of signs and billboards being an evidence of that. And yet, it is often the poorly thought-through visibility of some spatial elements that causes wayfinding difficulties. For instance, signs are well-visible only at a certain angle and approaching the sign is not equally probable at all angles. In multilevel buildings, visibility of staircases and the visibility of space after exiting staircases has been shown to have the key impact on users’ ability to orient themselves after changing the building level. Changing the direction of locomotion (turns and u-turns) are key events where designing what the user sees before and after, can make a difference between finding your way to the destination and becoming hopelessly lost.

For this thesis topic, the student will learn how to perform a Visibility Analysis of a building (WWU Psychology building or GEO1) or of an outdoor environment (Muenster Zoo) and use it to identify potential navigational challenges. The work will conclude with suggesting improvements in design and simulating their expected outcome.

Reading:

Hölscher, C., Meilinger, T., Vrachliotis, G., Brösamle, M., & Knauff, M. (2006). Up the down staircase: Wayfinding strategies in multi-level buildings. Journal of Environmental Psychology, 26(4), 284–299.

Further reading:

Carlson, L., Holscher, C., Shipley, T. F., & Conroy Dalton, R. (2010). Getting Lost in Buildings. Current Directions in Psychological Science, 19(5), 284–289. http://doi.org/10.1177/0963721410383243

Xie, H., Filippidis, L., Gwynne, S., Galea, E. R., Blackshields, D., & Lawrence, P. J. (2007). Signage Legibility Distances as a Function of Observation Angle. Journal of Fire Protection Engineering, 17(1), 41–64. http://doi.org/10.1177/1042391507064025

Müller-Feldmeth, D., Schwarzkopf, S., Büchner, S. J., Hölscher, C., Kallert, G., Stülpnagel, R. von, & Konieczny, L. (2014). Location Dependent Fixation Analysis with Sight Vectors. Locomotion as a Challenge in Mobile Eye Tracking. In P. Kiefer, I. Giannopoulos, M. Raubal, & A. Krüger (Eds.), Proceedings of the 2nd International Workshop on Eye Tracking for Spatial Research co-located with the 8th International Conference on Geographic Information Science (GIScience 2014) (pp. 67–71). Vienna, Austria.

Autor: Lasse Einfeldt
Betreuer: Jakub Krukar

Deutsch:

Die große Zahl gewaltsamer Konflikte weltweit und das Ausmaß, zu dem Menschenrechte hierbei verletzt werden, machen eine genaue Überwachung und Dokumentation von Konflikten unabdingbar. Da eine ausführliche bodengebundene Überwachung des Kriegsverlaufes und seiner Auswirkungen jedoch -insbesondere in abgelegenen Regionen- häufig kaum möglich ist, werden Fernerkundungsmethoden und GI-Technologien immer häufiger dazu eingesetzt, Kampfhandlungen in Kriegsgebieten zu dokumentieren. Satellitenbilder können zum Beispiel visuellen Zugang zu schwer erreichbaren Regionen ermöglichen und lokale Berichte über Gewalt und Zerstörung bestätigen. Die meisten praktischen Anwendungen verlassen sich dabei bisher vor allem auf die manuelle Bildanalyse und Identifikation von verdächtigen Objekten (z.B. zerstörte Gebäude). Der Zeit- und Kostenaufwand solcher Analysen ist jedoch erheblich. Eine Möglichkeit, mit dem immensen Aufwand umzugehen, ist die Verteilung der Arbeit auf verschiedene Analysten in sogenannten crowd-sourcing Netzwerken (mit Hilfe von micro-tasking Anwendungen, siehe z. B. http://www.tomnod.com/). Hierbei werden die Fernerkundungsdaten in kleinere Ausschnitte eingeteilt und individuell von Freiwilligen auf z.B. zerstörte Gebäude untersucht. Eine andere Strategie ist die Verwendung (semi-) automatischer Bildanalyse- und Klassifikationsmethoden zur Identifikation von Zerstörungen, um den manuellen Aufwand zu verringern. Momentan konzentrieren sich die verschiedenen Ansätze entweder auf die web-mapping/crowd-sourcing Ansätze oder die Methoden zur automatischen Bildanalyse.

Ziel der Bachelorarbeit ist es, ein prototypisches web-mapping/crowd-sourcing Werkzeug zu entwickeln, dass beide genannten Strategien verbindet. Hierbei sollen bereits vorhandene Ergebnisse aus automatischen Bildanalysen integriert werden, indem sie als Basis für die Erstellung und Priorisierung der Bildausschnitte für die manuelle Analyse dienen. Bildausschnitte mit hoher Wahrscheinlichkeit/Dichte von Zerstörungen (gemäß der Ergebnisse der automatischen Methoden) sollen automatisch höhere Priorität im folgenden manuellen Analyseprozess bekommen. Die zu verarbeitenden Eingabedaten können dabei in unterschiedlichem Detaillierungsgrad vorliegen, z.B. Polygone mit unterschiedlichen Wahrscheinlichkeiten/Dichten von Zerstörung oder einzelne Punkte, die die Position von zerstörten Gebäuden anzeigen. Das zu entwickelnde Werkzeug sollte eine Methode enthalten, um mit Hilfe dieser Daten sinnvoll kleinere Ausschnitte aus den vorliegenden Fernerkundungsbildern zu erstellen und diese zu priorisieren. Zusätzlich sollten Werkzeuge bereitstehen, um Nutzer/innen eine sinnvolle Visualisierung bi-temporaler Daten (vor und nach angeblicher Attacken) und das Markieren von Zerstörungen zu ermöglichen. Optional können natürlich weitere Methoden oder Schnittstellen für die Kombination automatischer und manueller Analyse erdacht und entwickelt werden.

English:

The high number of violent conflicts worldwide and the extent to which human rights are abused during acts of war stress the need for close monitoring and documentation of conflict areas to strengthen public international law. As a comprehensive ground‐level documentation of combat impacts is often hardly possible in conflict areas, satellite imagery and geospatial technology are increasingly being used to document and communicate human rights issues. Satellite images can for example provide visual access to remote or insecure areas as well as visual evidence to corroborate on-the-ground reports on human rights violations. Most of the practical applications rely on the manual image interpretation and identification of objects of interest. However, the time consumption of such analyses is substantial. One strategy to cope with the immense workload is to make use of a decentralized approach and distribute the work among several analysts e.g. within crowd-sourcing networks (by use of micro tasking tools, see e.g. http://www.tomnod.com/). Here the images are divided into subsets and individually investigated by volunteers. Another strategy is to use computer assisted methods for (semi-) automatic information extraction to reduce the analysis workload. Current approaches focus on either web-mapping for collaborative monitoring of violence or on image analysis and classification methods for automatically detecting structural damage in conflict areas.

The aim of this thesis is to develop a prototypical web-mapping and micro-tasking tool for collaborative conflict monitoring which combines both abovementioned fields. It should integrate existing results from automatic classification methods by using them as a basis for the automatic creation and prioritization of areas of interest. Areas with a high probability/density of destruction get a higher priority for the subsequent manual analysis by volunteers. The input data can be in different levels of detail, e.g. polygons of areas with different probabilities of destruction or even point data indicating the location of destructed buildings. The web application should include a method to create and prioritize image subsets based on this input data and contain tools for a meaningful visualization of bi-temporal image data (pre- and post-conflict image) as well as for manually tagging destructed buildings. Optionally, further methods and interfaces combining automatic and manual image analysis can be developed.

Autor: Sofian Slimani
Betreuer: Christian Knoth

Bioenergy is renewable energy derived from biological sources, such as crops. One type of bioenergy is ethanol made from sugar cane, used as a biofuel for cars. Although ethanol is renewable for sure, there have been concerns whether it is also sustainable, because of the potential impacts of the sugar cane plantations, for example on deforestation, socio-economic conditions of the workers and water use.

One way to assess the latter impact is the water footprint. The water footprint is an indicator of freshwater use for making a certain product or delivering a service (Hoekstra et al. 2011). The vast expansion of sugar cane in Brazil in the last decades, mainly for ethanol production, was an incentive for Rodriguez et al. (2016) to assess the water footprint of the suitable expansion areas in Brazil. Yet, the fact that an area is suitable for sugar cane expansion does not mean that expansion will take place, because expansion is also driven by market demand.

The aim of this BSc thesis is to use a set of existing sugar cane expansion scenarios for 2030 from a demand-driven land use change model (Verstegen et al., 2016, van der Hilst et al., in review) to re-assess the future water footprint of sugar cane for ethanol in Brazil. This will be done using the methodology from Rodriguez et al. (2016) and the high-resolution maps of water-related variables developed by Xavier et al. (2016).

References:

Van der Hilst, F., Verstegen, J.A., Woltjer, G., Smeets, E., Faaij, A.P.C. (in review). Mapping direct and indirect land use changes resulting from biofuel production and the effect of LUC mitigation measures. In review at Global Change Biology Bioenergy.

Hoekstra, A. Y., Chapagain, A. K., Aldaya, M. M. & Mekonnen, M. M. (2011). Water Footprint Assessment Manual: Setting the Global Standard. http://waterfootprint.org/en/resources/publications/water-footprint-assessment-manual-global-standard/

Rodriguez, R., Scanlon, B.R. and King, C.W. (2016). Sugarcane water footprint in the suitable areas for crop in Brazil. CLIMA Policy Brief #1, Centro Clima/COPPE/UFRJ, Rio de Janeiro, 6 p. http://testsite1.hospedagemdesites.ws/wp-content/uploads/2016/11/CLIMA-PolBrief-1-Water-footprint-cane.pdf

Verstegen, J.A., van der Hilst, F., Woltjer, G., Karssenberg, D., de Jong, S.M., Faaij, A.P.C. (2016). What can and can't we say about indirect land-use change in Brazil using an integrated economic – land-use change model? Global Change Biology Bioenergy 8(3), 561-578.

Xavier, A. C., King, C. W. & Scanlon, B. R. (2015) Daily gridded meteorological variables in Brazil (1980–2013). Int. J. Climatol. 36, p. 2644-2659. doi:10.1002/joc.4518

Autor: Yannick Paulsen
Betreuer: Judith Verstegen, Moritz Hildemann

Mobility infrastructure has a great impact on the sustainable development of cities. An efficient non-motorized infrastructure can help Sustainable Development Goals (SDGs) by promoting public health (SDG 3.4), contributing to better air, water, and soil quality (SDG 3.9), increasing accessibility and affordability of public transportation (SDG 11.2), reducing the environmental impact in cities (SDG 11.6.), helping to climate control (SDG 13.2). German Sustainable Building Council (Deutsche Gesellschaft für Nachhaltiges Bauen- DGNB) provides comprehensive tools to assess the sustainability of buildings and neighborhoods in Germany since 2007. The tools are developed and updated regularly according to the SDGs and local sustainability strategies. Non-motorized traffic is covered by DGNB Quartier in 2020 with the aim of efficient use of resources, increased affordability, and increased user comfort which provides better experience and accessibility especially for people with reduced mobility.

BSc - In the scope of the BSc thesis, the focus will be given to the assessment of cycling infrastructure in Münster. The data collection and analysis will be based on the indicators defined by the German Sustainable Building Council (Deutsche Gesellschaft für Nachhaltiges Bauen- DGNB), Neighbourhood certification (DGNB Quartier) (sub section Technische Qualität - TEC 3.2). Data collection and analysis will include the assessment of quantity and quality of city’s existing cycling infrastructure such as integration of the cycling network to other transportation modes and land uses, the quantity and quality of bicycle parking spaces, and signalisation. The student will automate the assessment of indicators through an algorithm developed in SQL or Python, visualise the results on the preferred system, and recommend a roadmap for future applications to achieve maximum score (30 points) stated in the DGNB Quartier sustainability certification system.

MSc - The MSc thesis aims to create an interactive City Dashboard for Münster focusing on cycling infrastructure in the city centre. Complementary to the data collection and analysis processes described in the BSc thesis, the student is expected to develop a web-based, interactive dashboard that enables users of the city to monitor the status quo of the cycling infrastructure and investigate the impact of possible interventions (e.g. increasing the amount of the cycling paths or bicycle parking spaces) on the overall quality of non-motorised mobility infrastructure.

References:

Deutsche Gesellschaft für Nachhaltiges Bauen (2020), DGNB Quartiere Kriterienkatalog, https://static.dgnb.de/fileadmin/dgnb-system/de/quartiere/kriterien/DGNB-Kriterienkatalog-Quartiere-Kommentierungsversion-2020.pdf

Autor: Fabian Fermazin (BSc), Lorenz Beck (MSc)
Betreuer: Simge Özdal Oktay

During disaster emergencies such as fires, floods, landslides, etc., fire departments are usually one of the first responders in official capacity on site. On of the most important first and ongoing tasks that firemen have to perform is to evaluate the disaster scene to, among other things, establish the scope and spatial extent of the disaster and take stock of important landmarks in the vicinity. These landmarks include water sources and other spatial features such bridges or hospitals. Part of the aforementioned task involves creating a series of sketch maps of the surroundings of the disaster scene and annotating them accordingly.

The challenge for this thesis is to determine the necessary data to be captured and to specify practical methods for capturing and communicating them. The firemen’s work involves a many different tasks and several sketches likely appear in the response to a single event. Moreover, for large scale events, several sketches may be drawn of different parts of the surroundings of the disaster scene. How can the critical information contained in these sketches be shared between firemen and with the operations control centers?

Status quo

Fire men sketch site plans of affected building complexes on prepared sheets
Symbols (tactical signs) are placed around the map with lines drawn from each symbol to each location of interestin the sketch where the feature represented by the symbol is located.

Idea for thesis

capturing of handdrawn sketch (camera)
georeferencing of tactical sign
no full extraction of sketch required, but a rough georeferencing
assessment of existing sketched site plans

Intended for Master GI thesis

A version of this description with illustrations can be found at http://goo.gl/QM3tr7

Contact

Malumbo Chipofya (mchipofya@uni-muenster.de)

Holger Fritze (h.fritze@uni-muenster.de)

Autor: Christian Kruse
Betreuer: Angela Schwering

Along with the increasing proliferation and power of mobile devices, mobile maps (e.g. in pedestrian navigation systems) become both feasible and popular [Allen, 2000]. In contrast to the navigation mode in car navigation systems, pedestrians prefer route instructions based on salient objects [Kluge and Asche, 2012]. Although it is easy for users to get guided to a location, research suggests that the effects are negative. Moreover, users become device-focused and develop a reduced understanding of the environment [Munzer et al., 2006]. Accordingly, users might get lost in cases of inaccurate instructions or failures of the system as they only focus on the given route and turning-point instructions. Consequently, studies suggest that wayfinding and learning of the environment can be influenced through visual presentation modes with mobile applications [Munzer et al., 2012]. One type of information that are mostly not considered in mobile navigation solutions are landmarks. However, it has shown that landmarks are an important supportive element in wayfinding tasks [Golledge, 1999]. One of the key strengths of a map is that it can visualize features and their spatial relationships of a large area. Though, the limited space of mobile devices leads to a visualization of only a discrete view of an area. As consequence, the acquisition of spatial knowledge is impacted
with respect to accuracy and response time [Dillemuth, 2009]. Since the space of
the display is limited, landmarks are often outside of the displayed area. Accordingly, they have to be mapped on-screen to overcome this limitation. Research has already shown that displaying distant landmarks on-screen holds positive effects on supporting persons acquisition of directional knowledge that benefits spatial orientation [Li et al., 2014]. For the reason that the chosen visualization does not convey information about distance from the user’s position to the distant object a better visualization has to be provided. Research already provides several approaches to display distant objects on small displays (e.g. [Baudisch and Rosenholtz, 2003], [Gustafson et al., 2008], [Bertel et al., 2014]). However, given approaches are mainly focused on guiding a user to a distant
location. Therefore, this thesis will aim at adapting common approaches of research to display off-screen landmarks in order to investigate in what extent spatial orientation is supported while navigating through traffic.

Autor: Daniel Schumacher
Betreuer: Angela Schwering

The usage of do-it-yourself (DIY) sensor stations based on open-source hardware for participatory sensing as a basis for large-scale sensor networks is a novel approach in the field of citizen science. In that context, DIY sensors can build a basis for large-scale sensor network applications. Since the installation is performed by non-professionals, extensive user support has to be provided in order to achieve satisfactory results.

The SenseBox is an open-source toolkit for participatory sensing, which offers well-documented tutorials for sensor applications based on Arduino microcontrollers. This system has been applied in scientific workshops with secondary school students to teach them programming in a playful and simple way. All data that is being collected with the SenseBox construction kits is published on OpenSenseMap, a platform for sharing open sensor data. There was an increasing demand of the DIY toolkits after the project was publicly promoted and the OpenSenseMap was officially launched. Consequently this approach was adopted to a standalone DIY sensor station for participatory sensing. A second version of the SenseBox was developed, which is more focusing on long-term deployments of local environments than on an educational approach.

After an initial test phase where citizens were equipped with SenseBox construction kits for continuous measurements, it was discovered that most of the stations were disconnected after a short time period. Subsequently a user study was performed to reveal possible error sources during the wiring process, software installation and integration into the sensor network. It turned out that missing general computer skills, like the installation of application software, led to larger problems than wiring of hardware parts.

This Thesis focuses on usability enhancements for the SenseBox and OpenSenseMap to enable citizen driven long-term deployments of DIY sensor stations in outdoor environments.

The research fields of Human Computer Interaction (HCI) and Usability Engineering (UE) provide well described guidelines and frameworks for designing intuitive user interfaces. These concepts can be adapted to the open hardware approach of SenseBox, the sensor registration on OpenSenseMap and the documentation material. Intermediate results of an ongoing test run are demonstrating that the usability of the project can be enhanced with the methods provided by the heuristics of UE.

Autor: Jan Wirwahn
Betreuer: Prof. Dr. Angela Schwering

Computational research introduces challenges when it comes to reproducibility, i.e. re-doing an analysis with the same data and code. A current research project at ifgi developed a new approach called Executable Research Compendia (ERC, see https://doi.org/10.1045/january2017-nuest) to solve some of these challenges. ERC contain everything needed to run an analysis: data, code, and runtime environment. So they can be executed “offline” in a sandbox environment. An open challenge is the one of big datasets and reducing data duplication. While the idea of putting “everything” into the ERC is useful in many cases, once the dataset becomes very large it is not feasible to replicate it completely for the sake of reproducibility/transparency and to some extent for archival.

This thesis will create a concept for allowing ERC to communicate with specific data repositories (e.g. PANGAEA, GFZ Data Services) extending on previous work (https://doi.org/10.5281/zenodo.1478542). The new approach should let ERCs “break out” of their sandbox environments in a controlled and transparent fashion, while at the same time more explicitly configuring the allowed actions by a container (e.g. using AppArmor).

Since trust is highly important in research applications, the communication with remote services must be exposed to users in a useful and understandable fashion. Users who evaluate other scientists ERC must know which third party repositories are used and how. The concept must be (i) implemented in a prototype using Docker containerization technology and discussed from viewpoints of security, scalability, and transparency, and (ii) demonstrated with ERC based on different geoscience data repositories, e.g. Sentinel Hub, and processing infrastructure, e.g. openEO or WPS, including an approach for authentication. Furthermore it could be evaluated to define the sandbox more explicitly, and if the communication between ERC and remote service can be captured and then cached for an additional backup, so that future execution may re-use that backup.

Prior experience with Docker is useful but not a strict requirement.

Contact: Daniel Nüst

Autor: Niklas George
Betreuer: Daniel Nüst
Download thesis PDF

Precipitation plays an important role within the hydrological cycle and has impact on human life. Estimating the precipitation amount at a specic location at a particular time can be crucial for agriculture, energy supply and risk management, as well as for research in order to provide better understanding of patterns of water distribution. However data about precipitation mostly relies on ground measurement stations which are unevenly distributed in space and rarely placed at locations diffcult to access. An additional diffculty of correct estimates is the uneven distribution of precipitation within time. Due to the regularity of satellites passing over a specic location their measurements of the atmosphere represent a valuable data source. However the availability of freely accessible precipitation estimation products derived form satellite sources is limited for high latitudes of the Earth. The aim of this master thesis is to evaluate estimation products provided by the Global Precipitation Measurement

(GPM) mission for the case of heavy rain at the West-Coast of Norway. In this case study, the focus is on the reflection of ground measured observations by the satellite products for the location of Bergen as well as for a larger spatial extent covering the West-Coast of Norway within the latitudes 62N and 58N. Sources for the ground measurements will be data from horizontal weather radars and an interpolated precipitation grid based on measurements from stations. For the location of Bergen additionally ground measurements preformed with a disdrometer, a micro-rain radar and a rain gauge will be taken into account. For the comparison of satellite estimated precipitation rates with ground measurements from dierent sources the Pearson Correlation Coeffcient, the Relative Bias and the Root Mean Square Error will be calculated. As an extended goal the probability of precipitation detection by the satellite product might be assessed.

Autor: Alicja Balfanz
Betreuer: Judith Verstegen

A dataset of railway tracks of good positional accuracy would be an important asset to railway companies and researchers. Railway track data is provided for free by some sources, namely the OpenRailwayMap, INSPIRE railway network and the Deutsche Bahn. However, the geometry of the track is not well-defined in several portions and they also lack positional accuracy and completeness. The Institute of Transportation Systems, Deutsches Zentrum für Luft- und Raumfahrt (DLR) has developed a measurement vehicle called the ‘RailDriVE’ that has several sensors, including several high quality Global Navigation Satellite System (GNSS) receivers, an Inertial Measurement Unit (IMU) and a Laser Scanner.

The goal of the current work is to compare three different approaches to create a track of good quality from the measurements made by these sensors. The performance of these approaches in different environmental conditions (for example, open areas, forests) will also be assessed. In the first approach, the GNSS data points will be filtered based on their quality and then fused with IMU data using advanced sensor fusion algorithms. The center line of the track will be derived from the GNSS-IMU fused data. For the second approach, the point cloud obtained from the laser scanner data will be georeferenced using GNSS data and the center line of the track will be derived from the georeferenced point cloud. In the third approach, the GNSS-IMU fused points from the first approach will be used to georeference the laser scanner data and the center line will be derived from the georeferenced point cloud similar to the second approach. The accuracy of the result of each approach will be evaluated using aerial images provided by the GeoDataPortal of Sachsen as the reference data. Finally, the best result obtained would be submitted to OpenRailwayMap so that it is beneficial to the community.

Autor: Sangeetha Shankar
Betreuer: Judith Verstegen, Lucas Schubert

openEO develops an open API to connect R, Python and Javascript clients to big Earth observation cloud back-ends in a simple and unified way. Back-ends process user-defined algorithms on remote sensing data sets - usually image-based - within their cloud infrastructure. An important aspect is to facilitate users to switch between back-ends easily while still getting consistent and comparable processing results. Back-ends use different IT infrastructure and software to process data although they share the same specification for processes and for communication between clients and back-ends: the openEO API. It is still necessary to ensure that processes comply to the specification. As a consequence, the results from back-ends are often not comparable by default and need to be checked for compliance with the specification. One way to ensure compliance is by processing a certain standardized, reference data sets and validating the results. The openEO project still has to select such data sets. Additionally, the differences in infrastructure and software may eventually lead to at least small differences in the processing results, either due to rounding in floating point arithmetic or implementation details. Therefore there needs to be a certain threshold that the results are allowed to differ. This thesis aims to solve the issues raised by

defining which aspects an image-based data set need to fulfil for our validation purposes,
selecting suitable image data sets for validation purposes,
defining the concrete rules and a workflow for validation,
and implementing a prototype for the specified workflow.

The scope of the thesis can be adapted to to fit the requirements of either a bachelor thesis or a master thesis. Some more information can be found in the corresponding openEO API GitHub issue.

Contact

Edzer Pebesma - edzer.pebesma@uni-muenster.de
Matthias Mohr - m.mohr@uni-muenster.de

Autor: Simon Schulte
Betreuer: Edzer Pebesma

The R community maintains the Comprehensive R Archive and Network (CRAN), an infrastructure for building and testing more than 12000 R extension packages. The CRAN Task Views Spatial and SpatioTemporal (https://cran.r-project.org/view=Spatial, https://cran.r-project.org/view=SpatioTemporal) comprise around 220 packages for geospatial data modelling, analysis, and visualisation. At the heart of R's success lie CRAN's testing procedures, which constantly ensure functionality and compatibility. These procedures are crucial for core packages of R communites of practice, such as the geospatial community (R-Sig-geo/R-spatial). R-spatial's core packages provide geospatial data structures and data import/export, such as sp (https://cran.r-project.org/web/checks/check_results_sp.html), sf (https://cran.r-project.org/web/checks/check_results_sf.html), and raster (https://cran.r-project.org/web/checks/check_results_raster.html). The datastructures are used by large number of packages. While CRAN checks different "Flavours" of operating systems and compilers, it does not check alternative implementations of the R language.

This thesis is a first exploration of the handful of new and still uncommon R implementations (such as fastr, MRO, Renjin, cf. http://bit.ly/docker-r) and their capabilities for geospatial analysis. It builds upon existing prototypical Linux containers for rare R distributions and should use them for (a) building and running tests for geospatial packages and (b) running benchmarks for typical geospatial workflows across different implementations of R.

The R-hub builder (https://builder.r-hub.io/advanced; already packaging platforms as containers, see https://github.com/r-hub/rhub-linux-builders), build systems like Travis or Appveyor, and benchmarking packages (http://www.alexejgossmann.com/benchmarking_r/, e.g. http://bench.r-lib.org/) should be evaluated and if possible extended.

The new contribution of this work is adding alternative R distributions as a further dimension to the test matrix. This work can provide a better understanding of the state of the art for geospatial tools in alternatives to the mainstream R ecosystem.

This thesis requires experience with R and Linux, and provides a great opportunity to master the latest container technologies. The following research questions should be answered:

What R-spatial packages be installed in alternative R implementations?

What are the main obstacles to a comprehensive geospatial toolset in alternative R implementations?

What is the role system libraries play in the R-spatial ecosystem from the perspective of alternative R implementations?

How can containers support transparent benchmarking across R versions and implementations?

Autor: Ismail Sunni
Betreuer: Edzer Pebesma

Cities are centers of demand for environmental resources, such as food. In a recent paper, Dermody et al. (2018) present a conceptual modelling framework for capturing interdependencies and feedbacks in the global food system with a focus on cities. In their framework, cities are agents and are comprised of an urban area and an associated hinterland.

The paper highlights that cities have coevolved with transport networks (physical road and rail infrastructure), which radiate from cities into the surrounding environment to deliver the environmental resources to urban citizens. Thus, it can be expected that the topology of the transport network represents the connectedness of hinterlands to cities. One way to subdivide a network based on connectedness is with community detection algorithms. These algorithms decompose networks into sub-units or communities, with a maximum number of connections within the community and a minimum number of connections in-between communities (e.g. Blondel et al. 2008). In a recent paper, for example, communities are detected in the London street network to identify housing sub-markets (Law et al., 2017).

The aim of this thesis is develop a method for defining city-hinterland pairs using a community detection algorithm applied on the transport network. The hypothesis is that, on a transport network of a state or a country, each detected community will correspond to an individual city-hinterland pair. A potential research question in this respect is: To what extent do the city-hinterland pairs detected by this community detection approach correspond to the ones detected with a simpler method like Thiessen polygons and/or with sub-national administrative areas?

This thesis is supervised by Judith Verstegen (IFGI) and Brian Dermody (Utrecht University). The study area may be defined by the student in consultation with the supervisors.

References

Blondel et al., 2008, Fast unfolding of communities in large networks. Journal of Statistical Mechanics: Theory and Experiment, doi: 10.1088/1742-5468/2008/10/P10008.

Dermody et al. 2018, A framework for modelling the complexities of food and water security under globalization. Earth System Dynamics 9, p. 103–118, doi: 10.5194/esd-9-103-2018.

Law, 2017, Defining Street-based Local Area and measuring its effect on house price using a hedonic price approach: The case study of Metropolitan London. Cities 60, p. 166–179, doi: 10.1016/j.cities.2016.08.008

Autor: Kushal Sharma
Betreuer: Judith Verstegen, Brian Dermody

Mobility infrastructure has a great impact on the sustainable development of cities. An efficient non-motorized infrastructure can help Sustainable Development Goals (SDGs) by promoting public health (SDG 3.4), contributing to better air, water, and soil quality (SDG 3.9), increasing accessibility and affordability of public transportation (SDG 11.2), reducing the environmental impact in cities (SDG 11.6.), helping to climate control (SDG 13.2). German Sustainable Building Council (Deutsche Gesellschaft für Nachhaltiges Bauen- DGNB) provides comprehensive tools to assess the sustainability of buildings and neighborhoods in Germany since 2007. The tools are developed and updated regularly according to the SDGs and local sustainability strategies. Non-motorized traffic is covered by DGNB Quartier in 2020 with the aim of efficient use of resources, increased affordability, and increased user comfort which provides better experience and accessibility especially for people with reduced mobility.

BSc - In the scope of the BSc thesis, the focus will be given to the assessment of cycling infrastructure in Münster. The data collection and analysis will be based on the indicators defined by the German Sustainable Building Council (Deutsche Gesellschaft für Nachhaltiges Bauen- DGNB), Neighbourhood certification (DGNB Quartier) (sub section Technische Qualität - TEC 3.2). Data collection and analysis will include the assessment of quantity and quality of city’s existing cycling infrastructure such as integration of the cycling network to other transportation modes and land uses, the quantity and quality of bicycle parking spaces, and signalisation. The student will automate the assessment of indicators through an algorithm developed in SQL or Python, visualise the results on the preferred system, and recommend a roadmap for future applications to achieve maximum score (30 points) stated in the DGNB Quartier sustainability certification system.

MSc - The MSc thesis aims to create an interactive City Dashboard for Münster focusing on cycling infrastructure in the city centre. Complementary to the data collection and analysis processes described in the BSc thesis, the student is expected to develop a web-based, interactive dashboard that enables users of the city to monitor the status quo of the cycling infrastructure and investigate the impact of possible interventions (e.g. increasing the amount of the cycling paths or bicycle parking spaces) on the overall quality of non-motorised mobility infrastructure.

References:

Deutsche Gesellschaft für Nachhaltiges Bauen (2020), DGNB Quartiere Kriterienkatalog, https://static.dgnb.de/fileadmin/dgnb-system/de/quartiere/kriterien/DGNB-Kriterienkatalog-Quartiere-Kommentierungsversion-2020.pdf

Autor: Fabian Fermazin (BSc), Lorenz Beck (MSc)
Betreuer: Simge Özdal Oktay

User experience of geospatial products is increasingly studied (see e.g. [1, 2]), but models describing the results of these studies for further reuse are still lacking. The aim of this thesis is to provide an approach to systematically build such models. Building these models is key to realize intelligent geovisualizations [3]. Tasks include:

Task1: Development of a prototype to collect data about the user experience of different types of map-based applications. This prototype can be mobile or not, and could investigate, for instance, the impact of color palettes, mean spacing between elements (e.g. menu items), size of the elements (e.g. icons, labels), visual hierarchy and the cross-device validity of the findings.

Task2: Conduct user studies to collect data about the user experience of a geospatial application under different conditions.

Task3: Model-fitting (i.e. find the mathematical function that describes the model most adequately).

References

[1] Degbelo, A. and Somaskantharajan, S. (2020) ‘Speech-based interaction for map editing on mobile devices: a scenario-based study’, in Alt, F., Schneegass, S., and Hornecker, E. (eds) Mensch und Computer 2020. Magdeburg, Germany: ACM, pp. 343–347. doi: 10.1145/3404983.3409996.

[2] Einfeldt, L. and Degbelo, A. (2021) ‘User interface factors of mobile UX: A study with an incident reporting application’, in Paljic, A., Peck, T., Braz, J., and Bouatouch, K. (eds) Proceedings of the 16th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (VISIGRAPP 2021) - Volume 2: HUCAPP. Online: SCITEPRESS - Science and Technology Publications, pp. 245–254. doi: 10.5220/0010325302450254.

[3] Degbelo, A. and Kray, C. (2018) ‘Intelligent geovisualizations for open government data (vision paper)’, in Banaei-Kashani, F., Hoel, E. G., Güting, R. H., Tamassia, R., and Xiong, L. (eds) 26th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems. Seattle, Washington, USA: ACM Press, pp. 77–80. doi: 10.1145/3274895.3274940.

Reading

Miniukovich, A. and Marchese, M. (2020) ‘Relationship between visual complexity and aesthetics of webpages’, in Bernhaupt, R. et al. (eds) Proceedings of the 2020 CHI Conference on Human Factors in Computing Systems. Honolulu, Hawaii, USA: ACM, pp. 1–13. doi: 10.1145/3313831.3376602.

Autor: Sulaxan Somaskantharajan
Betreuer: Auriol Degbelo

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