Research

PhD Thesis

ETH Zurich, Switzerland • January 2015

Urban air pollution is a major concern in many cities worldwide. Atmospheric pollutants are responsible for health problems ranging from asthma to cancer. Air pollution also causes environmental damages.

Monitoring airborne pollutants is of utmost importance to reliably assess the impact of air pollution on the human health, enable urban planners to craft and accurately evaluate new policies, and increase public awareness. Nowadays, air pollution is monitored by networks of highly accurate but fixed measurement stations. Hence, the gathered data has a low spatial resolution and can not be used to assess the spatial variability of pollutants in detail. As a result, little is known about the spatial distribution of air pollutants in urban environments.

 

Sensor node on top of a public transport vehicle.
Fine-grained pollution map.

 In this thesis, we tackle this challenge and derive fine-grained intraurban pollution maps valuable for a range of applications. We use compact low-cost sensors installed on top of public transport vehicles to obtain a high spatial measurement resolution within a large urban area. We develop algorithms that allow us to accurately monitor the phenomena of interest despite using noisy, low-cost sensors. Finally, we use the measurements to derive air pollution maps with a high spatial and temporal resolution.

[pdf] [ppt]

Publications

2018

  • Balz Maag, David Hasenfratz, Olga Saukh, Zimu Zhou, Christoph Walser, Jan Beutel, and Lothar Thiele. Ultrafine Particle Dataset Collected by the OpenSense Zurich Mobile Sensor Network. Zenodo, 2018. [data set]

2016

  • Michael Mueller, David Hasenfratz, Olga Saukh, Martin Fierz, and Christoph Hueglin. Statistical modelling of particle number concentration in Zurich at high spatio-temporal resolution utilizing data from a mobile sensor network. In Journal of Atmospheric Environment. Elsevier, 2016. [pdf]
  • Balz Maag, Olga Saukh, David Hasenfratz, and Lothar Thiele. Pre-Deployment Testing, Augmentation and Calibration of Cross-Sensitive Sensors. In Proceedings of the 13th European Conference on Wireless Sensor Networks (EWSN). Graz, Austria, February 2016. [pdf] [ppt]

2015

  • David Hasenfratz, Olga Saukh, Christoph Walser, Christoph Hueglin, Martin Fierz, Tabita Arn, Jan Beutel, and Lothar Thiele. Deriving High-Resolution Urban Air Pollution Maps Using Mobile Sensor Nodes. In Journal of Pervasive and Mobile Computing. Elsevier, 2015. [pdf]
  • Olga Saukh, David Hasenfratz, and Lothar Thiele. Reducing Multi-Hop Calibration Errors in Large-Scale Mobile Sensor Networks. In Proceedings of the 14th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN). Seattle, USA, April 2015. Best Paper Award. [pdf] [ppt]
  • David Hasenfratz, Tabita Arn, Ivo de Concini, Olga Saukh, and Lothar Thiele. Demo Abstract: Health-Optimal Routing in Urban Areas. In Proceedings of the 14th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN). Seattle, USA, April 2015. [pdf]

2014

  • Olga Saukh, David Hasenfratz, and Lothar Thiele. Route Selection for Mobile Sensor Nodes on Public Transport Networks. In Journal of Ambient Intelligence and Humanized Computing, 5(3). Springer, 2014. [pdf]
  • David Hasenfratz, Olga Saukh, Christoph Walser, Christoph Hueglin, Martin Fierz, and Lothar Thiele. Pushing the Spatio-Temporal Resolution Limit of Urban Air Pollution Maps. In Proceedings of the 12th IEEE International Conference on Pervasive Computing and Communications (PerCom). Budapest, Hungary, March 2014. Best Paper Award. [pdf] [ppt]

2013

  • David Hasenfratz, Silvan Sturzenegger, Olga Saukh, and Lothar Thiele. Spatially Resolved Monitoring of Radio-Frequency Electromagnetic Fields. In Proceedings of the 1st International Workshop on Sensing and Big Data Mining (in conjunction with ACM SenSys). Rome, Italy, November 2013. [pdf] [ppt]
  • Olga Saukh, David Hasenfratz, Christoph Walser, and Lothar Thiele. On Rendezvous in Mobile Sensing Networks. In Proceedings of the 5th Workshop on Real-World Wireless Sensor Networks (RealWSN). Como Lake, Italy, September, 2013. [pdf] [ppt]
  • David Hasenfratz, Olga Saukh, and Lothar Thiele. Model-Driven Accuracy Bounds for Noisy Sensor Readings. In Proceedings of the 9th IEEE International Conference on Distributed Computing in Sensor Systems (DCOSS). Massachusetts, USA, May 2013. [pdf] [ppt]
  • David Hasenfratz, Olga Saukh, Christoph Walser, Christoph Hueglin, Martin Fierz, and Lothar Thiele. Poster Abstract: Revealing the Limits of Spatio-Temporal High-Resolution Pollution Maps. In Proceedings of the 11th ACM Conference on Embedded Networked Sensor Systems (SenSys). Rome, Italy, November 2013. [pdf]

2012

  • Jason Jingshi Li, Boi Faltings, Olga Saukh, David Hasenfratz, and Jan Beutel. Sensing the Air we Breathe – The OpenSense Zurich Dataset. In Proceedings of the 26th International Conference on Artificial Intelligence (AAAI). Toronto, Canada, July 2012. [pdf]
  • David Hasenfratz, Olga Saukh, Silvan Sturzenegger, and Lothar Thiele. Participatory Air Pollution Monitoring Using Smartphones. In Proceedings of the 2nd International Workshop on Mobile Sensing (in conjunction with ACM/IEEE IPSN). Beijing, China, April 2012. [pdf] [ppt]
  • Olga Saukh, David Hasenfratz, Abouzar Noori, Tamara Ulrich, and Lothar Thiele. Route Selection for Mobile Sensors with Checkpointing Constraints. In Proceedings of the 8th International Workshop on Sensor Networks and Systems for Pervasive Computing (PerSeNS, in conjunction with IEEE PerCom). Lugano, Switzerland, March 2012. [pdf] [ppt]
  • David Hasenfratz, Olga Saukh, and Lothar Thiele. On-the-fly Calibration of Low-Cost Gas Sensors. In Proceedings of the 9th European Conference on Wireless Sensor Networks (EWSN). Trento, Italy, February 2012. [pdf] [ppt]
  • Olga Saukh, David Hasenfratz, A. Noori, Tamara Ulrich, and Lothar Thiele. Demo Abstract: Route Selection for Mobile Sensors with Checkpointing Constraints. In Proceedings of the 8th International Workshop on Sensor Networks and Systems for Pervasive Computing (PerSeNS, in conjunction with IEEE PerCom). Lugano, Switzerland, March 2012. [pdf]

2010

  • David Hasenfratz, Johannes Schneider, and Roger Wattenhofer. Transactional Memory: How to Perform Load Adaption in a Simple and Distributed Manner. In Proceedings of the International Conference on High Performance Computing and Simulation (HPCS). Caen, France, July 2010. [pdf]
  • David Hasenfratz, Andreas Meier, Clemens Moser, Jian-Jia Chen, and Lothar Thiele. Analysis, Comparison, and Optimization of Routing Protocols for Energy Harvesting Wireless Sensor Networks. In Proceedings of the 3rd International Conference on Sensor Networks, Ubiquitous, and Trustworthy Computing (SUTC). California, USA, June 2010. [pdf]
  • David Hasenfratz, Andreas Meier, Matthias Woehrle, Marco Zimmerling, and Lothar Thiele. Poster Abstract: If You Have Time, Save Energy with Pull. In Proceedings of the 8th ACM Conference on Embedded Networked Sensor Systems (SenSys). Zurich, Switzerland, November 2010. [pdf]