PhD defense by Jakob Schwalb-Willmann

PhD defense by Jakob Schwalb-Willmann

m

March 22, 2025

On March 31st at 2:00 PM, Jakob Schwalb-Willmann will defend his PhD thesis, “Potentials of Animal-Environment Interactions for Remote Sensing Research.” The public defense will be held at John-Skilton Str. 4a, Lecture Room 1. All interested staff, students, and members of the public are warmly invited to attend his presentation and the following discussion.

From the abstract: “Land Use/Land Cover (LU/LC) classifiers transform environmental data acquired using Earth observation (EO) techniques such as remote sensing into interpretable, quantifiable information. Both inside and outside academia, this information plays a crucial role in the understanding of land surface dynamics that result from global processes such as anthropogenic pressure or climate change. Conventional LU/LC approaches rely on human-defined classes and the collection, interpretation and labelling of ground truth data to train a classifier, e.g. through field and labelling campaigns. Thus, ground truth data generation is costly and labour-intensive, and tends to be subjective, since labelling relies on human perception and conception of the environment. Animals, like humans, perceive, interpret and differentiate the landscape, resulting in distinctive movement behavior across it, depending on their needs and the conditions surrounding them. This research proposes a semi-supervised Deep Learning (DL) approach employing movement tracked animals as landscape interpreters to generate ground truth data for classifying Animal Land Use (ALU) from environmental data. A neural network using bidirectional Long-Short Term Memory (LSTM) learned the relationship of movement trajectory sequences and associated environmental conditions. For this, data of more than 167 million trajectory locations, recorded for 7165 individuals belonging to 87 species which were tracked in the context of 140 research studies over 30 years, and more than 3 billion associated environmental observations were collected. Based on model error, potential animal-environment interactions (AEI) were separated from non-AEI. Using an adaptation of the Siamese neural network architecture, cluster-friendly representations were derived from AEI patterns based on their similarity and dissimilarity. In an unsupervised setting, AEI representations were clustered into AEI types which were used as ground truth labels to classify ALU from environmental data. The ALU classifier’s applicability was measured within 157 areas of interest (AOI), covering an area of 53167.55 km2 and a decade of yearly composited environmental data, for which ALU was predicted. To evaluate the robustness of the approach with respect to changes in both trajectory and environmental input data, a sensitivity analysis was conducted. In a subsequent co-occurrence analysis, ALU was compared to seven well-known human-defined LU/LC reference products to examine how reference class definitions matched with ALU. The proposed approach detected potential animal-environment interactions in circa 80 % of the provided samples. It achieved an accuracy of 0.881 in AEI representation learning, and an ALU classification accuracy of 0.806 (kappa = 0.627) for 343 111 AEI-derived ground truth samples within the AOIs. Sensitivity analysis showed that ALU classification strongly relied on optical
reflectances, evaporation, elevation, pressure and temperature data. The more species were represented in the input data, the higher was the observed ALU classification accuracy, while larger datasets derived from less species performed poorer. Co-occurrence analysis showed that in comparison to LU/LC, thematic resolution of ALU varied per land surface type, with higher thematic resolution in natural habitats such as grasslands and lower thematic resolution in urban areas. This research demonstrated how animals can be employed as land use interpreters, potentially complementing conventional LU/LC ground truth which is costly to collect, spatio-temporally sparse and caries subjectiveness through the human interpretation of the landscape.”

you may also like:

Our PhD Wall is Growing — and So Is Our Research Family!

Our PhD Wall is Growing — and So Is Our Research Family!

It’s been a remarkable year for our research team! The PhD Wall of Fame, showcasing all past and current doctoral researchers, has officially reached its limits — and we’ve had to expand it to make room for even more success stories. So far six PhD defenses have taken...

🎉 A Sweet Surprise for a Special Birthday!

🎉 A Sweet Surprise for a Special Birthday!

At our department, we not only work hard together — we also celebrate the milestones that make our team so special. This week, we had the joy of surprising our wonderful secretary Tine Linge on her 60th birthday! Early in the morning, colleagues gathered to prepare a...

Contribution at SilviLaser Conference in Quebec

Contribution at SilviLaser Conference in Quebec

At SilviLaser 2025 in Québec City, PhD candidate Julia Rieder (EORC, University of Würzburg and staff member of EO4CAM) presented her work on "European Beech under Drought: Effects of Topography, Competition and Soil Water Availability." Her study uses LiDAR to reveal...

EORC at Remote Sensing Symposium in Darmstadt

EORC at Remote Sensing Symposium in Darmstadt

On 2 October 2025, Dr. John Friesen and Dr. Julian Fäth from the Earth Observation Research Cluster (EORC) at the University of Würzburg and staff members of EO4CAM took part in the symposium "Vom Orbit zur Entscheidung: Satellitenfernerkundung in der...

New Team Member at the EORC: Sonja Mass

New Team Member at the EORC: Sonja Mass

Sonja Maas joined the Earth Observation Research Cluster (EORC) in October 2025 as a research assistant for the EO4CAM project. After finishing her bachelor's degree in forestry, Sonja Maas enrolled in the EAGLE M.Sc. program at the University of Würzburg, where she...

EAGLE MSc Student Isabella Metz Wins Prestigious IFHS Student Award

EAGLE MSc Student Isabella Metz Wins Prestigious IFHS Student Award

We are delighted to share the exciting news that our MSc student Isabella Metz has been awarded the 2025 International Federation of Hydrographic Societies (IFHS) Student Award for her outstanding research on: “Analysis of Uncertainties for Error Detection and...

Privacy Policy

Lehrstuhl für Fernerkundung & Lehrstuhl für Urbane Fernerkundung

Erdbeobachtung an der Universität Würzburg