@inproceedings{LadwigEversJansenetal.2020, author = {Ladwig, Philipp and Evers, Kester and Jansen, Eric J. and Fischer, Ben and Nowottnik, David and Geiger, Christian}, title = {MotionHub: Middleware for Unification of Multiple Body Tracking Systems}, series = {Proceedings of the 7th International Conference on Movement and Computing: MOCO '20: 7th International Conference on Movement and Computing, Jersey City, 15.07.2020-17.07.2020}, booktitle = {Proceedings of the 7th International Conference on Movement and Computing: MOCO '20: 7th International Conference on Movement and Computing, Jersey City, 15.07.2020-17.07.2020}, publisher = {ACM}, address = {New York}, isbn = {9781450375054}, doi = {10.1145/3401956.3404185}, pages = {1 -- 8}, year = {2020}, language = {en} } @inproceedings{TreskunovGerhardtNowottniketal.2019, author = {Treskunov, Anastasia and Gerhardt, Emil and Nowottnik, David and Fischer, Ben and Gerhardt, Laurin and S{\"a}ger, Mitja and Geiger, Christian}, title = {ICAROSmuIti - A VR Test Environment for the Development of Multimodal and Multi-User Interaction Concepts}, series = {Proceedings of Mensch und Computer 2019, MuC'19: Mensch-und-Computer, Hamburg, 08.09.2019-11.09.2019}, booktitle = {Proceedings of Mensch und Computer 2019, MuC'19: Mensch-und-Computer, Hamburg, 08.09.2019-11.09.2019}, editor = {Alt, Florian and Bulling, Andreas and D{\"o}ring, Tanja}, publisher = {ACM}, address = {New York}, isbn = {9781450371988}, doi = {10.1145/3340764.3345379}, pages = {909 -- 911}, year = {2019}, language = {en} } @inproceedings{TiatorFischerGerhardtetal.2018, author = {Tiator, Marcel and Fischer, Ben and Gerhardt, Laurin and Nowottnik, David and Preu, Hendrik and Geiger, Christian}, title = {Cliffhanger-VR}, series = {2018 IEEE Conference on Virtual Reality and 3D User Interfaces (VR), Reutlingen, 18.03.2018 - 22.03.2018}, booktitle = {2018 IEEE Conference on Virtual Reality and 3D User Interfaces (VR), Reutlingen, 18.03.2018 - 22.03.2018}, publisher = {IEEE}, isbn = {978-1-5386-3365-6}, doi = {10.1109/VR.2018.8446506}, pages = {1 -- 2}, year = {2018}, language = {en} } @inproceedings{TiatorGeigerDewitzetal.2018, author = {Tiator, Marcel and Geiger, Christian and Dewitz, Bastian and Fischer, Ben and Gerhardt, Laurin and Nowottnik, David and Preu, Hendrik}, title = {Venga!: climbing in mixed reality}, series = {Proceedings of the First Superhuman Sports Design Challenge on First International Symposium on Amplifying Capabilities and Competing in Mixed Realities - SHS '18, Delft, 02.07.2018 - 05.07.2018}, booktitle = {Proceedings of the First Superhuman Sports Design Challenge on First International Symposium on Amplifying Capabilities and Competing in Mixed Realities - SHS '18, Delft, 02.07.2018 - 05.07.2018}, editor = {Lukosch, Stephan and Kunze, Kai}, publisher = {ACM Press}, address = {New York}, isbn = {9781450364072}, doi = {10.1145/3210299.3210308}, pages = {1 -- 8}, year = {2018}, language = {en} } @article{NaraparajuLauLangeetal.2018, author = {Naraparaju, R. and Lau, H. and Lange, Martin and Fischer, Christian and Kramer, D. and Schulz, U. and Weber, Konradin}, title = {Integrated testing approach using a customized micro turbine for a volcanic ash and CMAS related degradation study of thermal barrier coatings}, series = {Surface and Coatings Technology}, volume = {337}, journal = {Surface and Coatings Technology}, publisher = {Elsevier}, issn = {0257-8972}, doi = {10.1016/j.surfcoat.2018.01.030}, pages = {198 -- 208}, year = {2018}, language = {en} } @misc{FischerNitzsche2024, author = {Fischer, Christian and Nitzsche, Olaf}, title = {Validierung atmosph{\"a}rischer Ausbreitungsmodelle durch experimentelle Untersuchungen}, edition = {v1.0}, publisher = {Zenodo}, doi = {10.5281/zenodo.14049791}, year = {2024}, abstract = {Meteorologische Daten, Freisetzungsraten und Konzentrationen in verschiedenen H{\"o}hen zur Validierung atmosph{\"a}rischer Ausbreitungmodelle.}, subject = {Emission}, language = {de} } @inproceedings{WeberVogelFischeretal.2010, author = {Weber, Konradin and Vogel, Andreas and Fischer, Christian and van Haren, G{\"u}nther and Pohl, Tobias}, title = {Airborne measurements of the Eyjafjallaj{\"o}kull volcanic ash plume over northwestern Germany with a light aircraft and an optical particle counter: first results}, series = {Lidar technologies, techniques, and measurements for atmospheric remote sensing VI : 20 - 21 September 2010, Toulouse, Franc}, volume = {7832}, booktitle = {Lidar technologies, techniques, and measurements for atmospheric remote sensing VI : 20 - 21 September 2010, Toulouse, Franc}, number = {7832OP}, editor = {Singh, Upendra N. and Pappalardo, Gelsomina}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {978-0-8194-8349-2}, issn = {0277-786X}, doi = {10.1117/12.869629}, year = {2010}, language = {en} } @incollection{WeberFischervanHarenetal.2006, author = {Weber, Konradin and Fischer, Christian and van Haren, G{\"u}nther and Krause, Horst and Bunte, Gudrun and Schweikert, Wenka and H{\"a}rdle, Thomas}, title = {Stand-Off Detection of Explosives of Suicide Bombers by Means of Open-Path FTIR Spectroscopy}, series = {Stand-Off Detection of Suicide Bombers and Mobile Subjects}, booktitle = {Stand-Off Detection of Suicide Bombers and Mobile Subjects}, editor = {Schubert, Hiltmar and Rimski-Korsakov, A.}, publisher = {Springer Netherlands}, address = {Dordrecht}, isbn = {9781402051579}, doi = {10.1007/1-4020-5159-X_16}, pages = {135 -- 143}, year = {2006}, language = {en} } @inproceedings{WeberEliassonArnasonetal.2015, author = {Weber, Konradin and Eliasson, Jonas and Arnason, Gylfi and R{\"o}gnvaldsson, {\´O}lafur and Thorsteinsson, Throstur and Palsson, Thorgeir and B{\"o}hlke, Christoph and Fischer, Christian and Smith, Paul and Jones, Roderic L. and Tirpitz, Lukas and Platt, Ulrich}, title = {Airborne Investigations and WRF - Model Calculations of the Bardarbunga-Holuhraun Eruption Plume}, series = {Geophysical Research Abstracts: EGU General Assembly 2015}, volume = {17}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2015}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2015}, abstract = {The eruption in Holuhraun is the largest producer of lava and gas in Iceland since 1783. The Volcanic Ash Research (VAR) group organized an airborne measurement campaign including 10 flights, where emissions of SO2 and ash concentrations were measured at the source and at the far plume. The highest SO2 concentration at the source was nearly up to 100 mg/m3. This is an extremely high value, compared to other airborne campaigns and a contamination considered to cause serious illness by the Icelandic Directorate of Health. Volcanic ash consisted of very fine particles, but the concentration was low when compared to other recent eruptions. Measurements of the far plume showed that scavenging is very active. The dispersion was successfully modeled with the Weather Research and Foreast (WRF-chem) model and analysis using the model showed that a large amount of the sulphur was precipitated in the Icelandic highlands.}, subject = {Vulkanismus}, language = {en} } @inproceedings{WeberFischerVogeletal.2013, author = {Weber, Konradin and Fischer, Christian and Vogel, Andreas and Pohl, Tobias and B{\"o}hlke, Christoph and Lau, Hendrik and Eliasson, Jonas and Palsson, Thorgeir}, title = {First results of an airborne release of volcanic ash for testing of volcanic ash plume measurement instruments}, series = {Recent Advances in Energy and Environmental Management}, volume = {Energy, Environmental and Structural Engineering Series 13}, booktitle = {Recent Advances in Energy and Environmental Management}, editor = {Mladenov, Valeri and Tasho, Tashev and Hui, Wang and Ivan, Kralov and Sergey, Stankevich and Pelin, Yildiz and Jon, Burley}, publisher = {WSEAS}, pages = {169 -- 172}, year = {2013}, subject = {Vulkanasche}, language = {en} } @inproceedings{VogelWeberFischeretal.2012, author = {Vogel, Andreas and Weber, Konradin and Fischer, Christian and Prata, A. J. and Durant, A. J.}, title = {Aircraft in situ and remote sensing measurements of emissions from Etna volcano, Sicily}, series = {Geophysical Research Abstracts: EGU General Assembly 2012}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2012}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2012}, abstract = {Volcanoes emit particles (silicates and sulphate aerosol) and gases (e.g., water and sulphur dioxide) which influence the radiative balance of the atmosphere. The rate at which sulphur dioxide oxidises to sulphate aerosol is poorly constrained and measurements of downwind abundance are required to quantify the rate at which this process occurs. During July and November 2011, a series of measurements were performed in emissions from Etna Volcano, Sicily, using the University of Applied Sciences (Dusseldorf) research aircraft. Both in situ and remote sensing instrumentation was simultaneously deployed to quantify the down-wind characteristics of gases and particles in the plume emitted by the volcano. In situ particle characteristics were measured using a Grimm 1.109 optical particle counter (microparticles 0.25-32 microns) and Grimm 1320 diffusion electrometer (nanoparticles 25-300 nanometers). Column abundance of sulphur dioxide was measured using a vertically-pointing differential optical absorption spectrometer (DOAS). These measurements were compared to horizontal pathlength-integrated measurements of sulphur dioxide from the Airborne Volcanic Imaging Object Detector (AVOID). Down-wind plume dispersion was discriminated through a series of aircraft transects below and through the volcanic plume. The emissions contained large amounts of nanoparticles relative to microparticles, which reflects gas-phase nucleation of sulphate aerosol. The AVOID system discriminated horizontal layering of volcanic aerosol at altitudes of up to 12,000 ft from a detection range of >50 km. Plume boundaries were discriminated using a combination of the in situ and DOAS measurements in order to compare to the pathlength-integrated measurements from AVOID.}, subject = {Forschungsflugzeug}, language = {en} } @inproceedings{PohlWeberFischeretal.2019, author = {Pohl, Tobias and Weber, Konradin and Fischer, Christian and Kramer, Tim}, title = {Investigation of the Temporal and Spatial Distribution of Ultrafine Particles with Stationary and Mobile Measurements at the International Airport in Duesseldorf}, series = {European Aerosol Conference 2019, 25.-30. August 2019, Gothenburg, Sweden}, booktitle = {European Aerosol Conference 2019, 25.-30. August 2019, Gothenburg, Sweden}, year = {2019}, subject = {Feinstaub}, language = {en} } @inproceedings{WeberKramerFischeretal.2019, author = {Weber, Konradin and Kramer, Tim and Fischer, Christian and Pohl, Tobias and B{\"o}hlke, Christoph}, title = {Evaluation of low cost and mid cost sensors for fine particulate matter at urban sites}, series = {Geophysical Research Abstracts: EGU General Assembly 2019}, volume = {21}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2019}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2019}, abstract = {High ambient air concentrations of fine particulate matter are a problem in many European cities, especially in traffic loaded street canyons. Therefore, the introduction of traffic restricted or traffic reduced areas is discussed as a countermeasure in several towns. However, at that point it is not always clear, in what extent the restriction of traffic in presently overloaded streets causes the exceeding of limit values in other areas of the town after the redirection of the traffic. Presently this cannot be recorded appropriately, when the concentrations of fine particulate matter are monitored only at rarely distributed single points by the official measurement systems of the environmental state agencies. On the other hand, meanwhile there are low cost and mid cost sensors for the measurement of fine particulate matter available, which enable the parallel monitoring with many measurement systems in an extended area of the town. By this way, the effect of traffic restrictions on the distribution of fine particulate matter in the city can potentially be observed. However, at this point the question arises, how reliable the results are, which are delivered by the low and mid cost sensors for fine particulate matter. For this reason different low cost and mid cost sensors have been evaluated for this study and intercompared with certified reference measurement systems for fine particulate matter. The study comprised the sensors SDS011 (Nova Fitness), which is in use already for several citizen science projects in Germany, SPS30 (Sensirion), OPC-R1 (Alphasense), OPC-N2 (Alphasense) and OPC-N3 (Alphasense). This study was performed at urban sites in D{\"u}sseldorf (Germany) for several weeks and covered different traffic loads and different meteorological situations, in order to get representative results. As atmospheric humidity can influence the measurement results, the humidity was measured in parallel to the fine particulate matter. It could be shown that the validity of the measurement results of fine particulate matter could be improved, when the parallel readings of the humidity were taken into account.}, subject = {Messtechnik}, language = {en} } @inproceedings{WeberThielkeFischer2019, author = {Weber, Konradin and Thielke, Jan and Fischer, Christian}, title = {Evaluation of selected physical parameters measured with smartphones}, series = {Verhandlungen der Deutschen Physikalische Gesellschaft e.V.}, booktitle = {Verhandlungen der Deutschen Physikalische Gesellschaft e.V.}, publisher = {Deutsche Physikalische Gesellschaft e.V.}, address = {Bad Honnef}, year = {2019}, subject = {Messtechnik}, language = {en} } @inproceedings{WeberHewelingPohletal.2019, author = {Weber, Konradin and Heweling, Georg and Pohl, Tobias and Fischer, Christian and B{\"o}hlke, Christoph}, title = {Untersuchung der raum-zeitlichen Variabilit{\"a}t verschiedener Luftschadstoffe in der Innenstadt D{\"u}sseldorfs mit mobilen Messungen}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft e.V.}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft e.V.}, publisher = {Deutsche Physikalische Gesellschaft e.V.}, address = {Bad Honnef}, year = {2019}, subject = {Luftverunreinigender Stoff}, language = {de} } @inproceedings{WeberKramerPohletal.2019, author = {Weber, Konradin and Kramer, Tim and Pohl, Tobias and Fischer, Christian}, title = {Evaluation und Vergleich von kosteng{\"u}nstigen Sensoren f{\"u}r Feinstaub}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft e.V.}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft e.V.}, publisher = {Deutsche Physikalische Gesellschaft e.V.}, address = {Bad Honnef}, year = {2019}, subject = {Messtechnik}, language = {de} } @inproceedings{WeberKramerFischeretal.2018, author = {Weber, Konradin and Kramer, Tim and Fischer, Christian and Pohl, Tobias and Schulenberg, Malte and Heweling, Georg and B{\"o}hlke, Christoph}, title = {Testing and evaluation of low-cost sensors for fine particulate matter PM10 and PM2.5}, series = {Geophysical Research Abstracts: EGU General Assembly 2018}, volume = {20}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2018}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2018}, abstract = {It is well known from medical studies that fine particulate matter has adverse effects to human health. However, exceeding of limit values for fine particulate matter PM10 and PM2.5 is still a problem in major German cities. Therefore, fine particulate matter is monitored in Germany by environmental state agencies at fixed stations with certified instruments. These certified instruments are able to deliver reliable and high quality results. However, because of the costs of these certified instruments and the maintenance efforts, only few measurements stations are placed in the cities at places, which are regarded as representative for the air pollution. On the other hand, it is of interest to know the concentration of fine particulate matter in areas and at places, which are not covered by the fixed measurement stations of the environmental state agencies. In this situation citizen science projects started in Germany using low cost sensors for fine particulate matter. In principle, with these low cost sensors citizens could measure fine particulate matter at places and in situations of their interests. However, at that point the question of reliability of the low cost sensor data arises. Therefore the Duesseldorf University of Applied Sciences (HSD) in Germany started a project for the testing and evaluation of low-cost sensors. For this reason 20 low-cost sensor units have been built up based on the SDS 011 sensor of Nova Fitness Inc. within the Laboratory for Environmental Measurement Techniques at HSD. The sensor measurement data can be transferred into a network and can be visualized on a digital map. This testing and evaluation at HSD of the low-cost sensors comprised: • Short term and long term comparison studies within the laboratory and at different urban sites with a certifiedwide range aerosol measurement system (Grimm WRAS). • Short term and long term comparison studies within the laboratory and at different urban sites with mid-cost sensors (Alphasense AN2). • Intercomparison testing and evaluation of sensors of the same production charge. • Intercomparison testing and evaluation of sensors of different production charges. • Testing and evaluation of the sensors at different meteorological conditions. The results of this testing and evaluation will be presented at the conference. Moreover, the potential of additional applications for low-cost sensors, e.g. for mobile measurements (multicopter UAS, bicycles, pedestrians) or for the validation of air pollution models, will be discussed}, subject = {Messtechnik}, language = {en} } @inproceedings{WeberFischerLangeetal.2017, author = {Weber, Konradin and Fischer, Christian and Lange, Martin and Schulz, Uwe and Naraparaju, Ravisankar and Kramer, Dietmar}, title = {Design and construction of a testbed for the application of real volcanic ash from the Eyjafjallaj{\"o}kull and Grimsv{\"o}tn eruptions to microgas turbines}, series = {Geophysical Research Abstracts: EGU General Assembly 2017}, volume = {19}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2017}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2017}, abstract = {It is well known that volcanic ash clouds emitted from erupting volcanoes pose a considerable threat to the aviation. The volcanic ash particles can damage the turbine blades and their thermal barrier coatings as well as the bearings of the turbine. For a detailed investigation of this damaging effect a testbed was designed and constructed, which allowed to study the damaging effects of real volcanic ash to an especially for these investigations modified microgas turbine. The use of this microgas turbine had the advantage that it delivers near reality conditions, using kerosene and operating at similar temperatures as big turbines, but at a very cost effective level. The testbed consisted out of a disperser for the real volcanic ash and all the equipment needed to control the micro gas turbine. Moreover, in front and behind the microgas turbine the concentration and the distribution of the volcanic ash were measured online by optical particle counters (OPCs). The particle concentration and size distribution of the volcanic ash particles in the intake in front of the microgas turbine was measured by an optical particle counter (OPC) combined with an isokinetic intake. Behind the microgas turbine in the exhaust gas additionally to the measurement with a second OPC ash particles were caught with an impactor, in order to enable the later analysis with an electron microscope concerning the morphology to verify possible melting processes of the ash particles. This testbed is of high importance as it allows detailed investigations of the impact of volcanic ash to jet turbines and appropriate countermeasures.}, subject = {Vulkanismus}, language = {en} } @inproceedings{WeberScharifiFischeretal.2017, author = {Weber, Konradin and Scharifi, Emad and Fischer, Christian and Pohl, Tobias and Lange, Martin and B{\"o}hlke, Christoph}, title = {Mobile measurements of air pollutants with an instrumented car in populated areas}, series = {Geophysical Research Abstracts: EGU General Assembly 2017}, volume = {19}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2017}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2017}, abstract = {Detailed mobile measurement of gases and fine particulate matter has been reported in the literature to be suitable to exhibit the air pollutants concentration in populated areas. This concentration is linked to the increase of number of cars, construction areas, industries and other emission sources. However, fixed measurement stations, mostly operated by environmental agencies, are limited in numbers and cannot cover a large area in monitoring. For this reason, to overcome this drawback, mobile measurements of the variability of gases (such as O3, NO, NO2) and particulate matter concentration were carried out during this study using an instrumented car. This car was able to deliver measurement results of all these compounds in a large area. The experimental results in this work demonstrate a large spatial variability of gases and fine particulate matters mainly depended on the traffic density and the location. These effects are especially obvious in the city core and the high traffic roads. In terms of fine particulate matter, this becomes evident for PM 10 and PM 2.5, where the mass and number concentration increases with arriving these zones.}, subject = {Messtechnik}, language = {en} } @inproceedings{WeberHewelingFischeretal.2017, author = {Weber, Konradin and Heweling, Georg and Fischer, Christian and Lange, Martin and B{\"o}hlke, Christoph}, title = {Octocopter investigation of the vertical and horizontal variation of ultrafine particles, fine particulate matter and soot in the traffic plume emitted from a Rhine river bridge in Duesseldorf, Germany}, series = {Geophysical Research Abstracts: EGU General Assembly 2017}, volume = {19}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2017}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2017}, abstract = {For this study an octocopter UAV was used for carrying an ultrafine (UFP) particle monitor, an optical particle counter (OPC) and a micro aethalometer. The UFP-monitor, based on electrical charging of UFPs, was able to count the number of UFPs and give an estimated mean diameter of the measured particles. The OPC, based on the particle induced light scattering of a laser beam, was able to detect aerosols in a size range of about 250 nm to 32 μm in 31 bins. The micro aethalometer measured the soot by optical attenuation of a light beam which is caused by carbon particulate matter. The octocopter with a lift off weight by 10.5 kg was especially designed and constructed at the University of Applied Sciences, Duesseldorf, for the measurement of air pollutants. It was equipped with eight 900 W electric engines and a pixhawk flight control. Technically this octocopter was able to climb up to altitudes of up to 2 km AGL. However, during this study an altitude range of several 10 meters was used. During this study about 60 octocopter flights were performed. The flights clearly revealed a plume of UFPs coming from the traffic on the bridge. This result was confirmed by various upwind and downwind measurements with the octocopter in the region of the bridge.}, subject = {Messtechnik}, language = {en} } @article{FischerWeberLangeetal.2016, author = {Fischer, Christian and Weber, Konradin and Lange, Martin and Fr{\"u}hsorger, Alexander and Roßkopf, C. and Pesch, Markus and Ziegler, V.}, title = {Bestimmung der Filtereffizienz von High Volume Air Condition (HVAC)-Systemen von verschiedenen Pkw mit realen Feinstaubbelastungen in Peking}, series = {Gefahrstoffe: Reinhaltung der Luft}, volume = {76}, journal = {Gefahrstoffe: Reinhaltung der Luft}, number = {11-12}, publisher = {Springer-VDI}, address = {D{\"u}sseldorf}, issn = {1436-4891}, pages = {437 -- 441}, year = {2016}, subject = {Luftfilter}, language = {de} } @inproceedings{WeberPohlFischeretal.2015, author = {Weber, Konradin and Pohl, Tobias and Fischer, Christian and Lange, Martin and B{\"o}hlke, Christoph}, title = {Determination of a Vertical Profile of Black Carbon by a Combined Application of a Light Research Aircraft and a Quadcopter Unmanned Aerial Vehicle - A Case Study Using an Airborne Ultraportable Micro-Aethalometer for Black Carbon Measurements at a Rural Site in Germany}, series = {Recent Researches in Electrical and Computer Engineering}, volume = {Recent Advances in Electrical Engineering Series 49}, booktitle = {Recent Researches in Electrical and Computer Engineering}, editor = {Valeri, Mladenov}, publisher = {WSEAS}, isbn = {978-1-61804-315-3}, issn = {1790-5117}, pages = {13 -- 18}, year = {2015}, subject = {Messtechnik}, language = {en} } @inproceedings{WeberFischerLangeetal.2015, author = {Weber, Konradin and Fischer, Christian and Lange, Martin and Pohl, Tobias and B{\"o}hlke, Christoph and Wagner, Frank and Mattis, Ina and Flentje, Harald and Sturm, Klaus and Barth, Joachim and Steinkopff, Thomas and Vogel, Andreas}, title = {Aircraft measurements compared with ceilometer measurements during a sahara dust period in Germany}, series = {Geophysical Research Abstracts: EGU General Assembly 2015}, volume = {17}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2015}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2015}, abstract = {A significant Sahara dust event took place at the beginning of April 2014 over large areas of Germany and Europe. The German Weather Service (DWD) detected and monitored the expansion and propagation of this dust cloud with a ceilometer network of more than 50 ceilometers. Moreover, these ceilometers were also able to track the altitude of the dust cloud at the positions of the ceilometers. Additionally, aircraft measurements over Germany and France were performed with two aircraft by the Duesseldorf University of Applied Sciences. These aircraft were equipped with optical particle counters (OPC) and were able to measure the particle size distribution within the Sahara dust cloud and as a result of this to calculate the particle mass concentration of the dust. The ceilometer measurements and the aircraft measurements complemented each other: whereas the ceilometers gave continuous information about the Sahara dust cloud at the ceilometer positions, the aircraft measurements delivered interpolating results between the ceilometer positions. Moreover, at several ceilometer positions intercomparison flights were performed by spiraling with the aircraft up or down around the ceilometer laser beam. This gave the unique possibility for comparing the remote sensing results of the ceilometers with the in-situ measurements of the aircraft. This study shows that a significant high amount of Saharan dust particles was transported over Germany during a several days long episode. Furthermore, the intercomparison study between the German ceilometer network and aircraft measurements results shows a good agreement. A combination of these techniques could help to detect the vertical and horizontal distribution of the dust cloud and additionally the particle mass concentration.}, subject = {Deutscher Wetterdienst}, language = {en} } @inproceedings{WeberFischerAmend2020, author = {Weber, Konradin and Fischer, Christian and Amend, Detlef}, title = {A new development of drop-sondes for the measurement of CO2-concentrations at extended volcanic areas}, series = {Physics of Volcanoes 2020}, booktitle = {Physics of Volcanoes 2020}, pages = {32}, year = {2020}, abstract = {One of the main compounds emitted by volcanoes or volcanic fields is CO2. This is not only emitted from localized craters, but can emerge as distributed and fugitive emissions on extended volcanic areas. In this situation it is of interest to explore the distribution and horizontal concentration profiles of the CO2-emissions. For this purpose new drop-sondes for sensor measurements of CO2 emissions are under development at the Duesseldorf University of Applied Sciences. These drop-sondes are designed to be dropped from aircraft or drones over volcanic areas in order to map the distributed CO2 concentrations over longer times in an unattended way. They are very lightweight and cheap, so that a large number of drop-sondes might be deployed even over remote areas or regions with difficult access. The data are transmitted with GSM broadcasting and can be visualized on a geographical map. The drop-sondes use an NDIR CO2 sensor as a base for the measurement unit. Additionally to CO2 the atmospheric pressure, temperature and humidity are measured. The sensor unit is mounted in a special shock absorbing housing, which is designed to absorb impacts from the touch down after dropping of the sensor and is able to resist even adverse weather conditions. First measurement results and more details of the design of the sensor unit will be presented in this contribution}, subject = {Sonde}, language = {en} } @inproceedings{WeberKramerFischeretal.2019, author = {Weber, Konradin and Kramer, Tim and Fischer, Christian and Pohl, Tobias and B{\"o}hlke, Christoph}, title = {Application and Feld-Testing of Different Low Cost Sensors for Particulate Matter}, series = {European Aerosol Conference 2019, 25.-30. August 2019, Gothenburg, Sweden}, booktitle = {European Aerosol Conference 2019, 25.-30. August 2019, Gothenburg, Sweden}, year = {2019}, subject = {Messtechnik}, language = {en} } @inproceedings{WeberReichardtFischeretal.2012, author = {Weber, Konradin and Reichardt, R. and Fischer, Christian and Moser, H. M. and Eliasson, Jonas}, title = {Computational Visualization of Volcanic Ash Plume Concentrations Measured by light Aircrafts over Germany and Iceland during the Recent Eruptions of the Volcanoes Eyjafjallaj{\"o}kull and Grimsv{\"o}tn}, series = {Recent advances in Fluid Mechanics, Heat \& Mass Transfer, Biology and Ecology}, booktitle = {Recent advances in Fluid Mechanics, Heat \& Mass Transfer, Biology and Ecology}, editor = {Jha, Manoj K. and Lazard, Myriam and Zaharim, Azami and Sopian, Kamaruzzaman}, publisher = {WSEAS}, isbn = {978-1-61804-065-7}, pages = {236 -- 240}, year = {2012}, subject = {Vulkanasche}, language = {en} } @inproceedings{VogelWeberFischeretal.2011, author = {Vogel, Andreas and Weber, Konradin and Fischer, Christian and van Haren, G{\"u}nther and Pohl, Tobias and Grobety, Bernhard and Meier, Mario}, title = {Airborne in-situ measurements of the Eyjafjalloj{\"o}kull ash plume with a small aircraft and optical particle spectrometers over north-western Germany - comparison between the aircraft measurements and the VAAC-model calculations}, series = {Geophysical Research Abstracts: EGU General Assembly 2011}, volume = {13}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2011}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2011}, abstract = {The eruption of the volcano Eyjafjallaj{\"o}kull (Iceland) in 2010 has caused a transportation of an ash dust plume over large areas of Europe. In April 2010 many airports in Europe were closed for several days because of the volcano ash plume and even in May 2010 several German and European airports were closed for shorter periods because of the danger caused by the volcanic ash dust. The VAAC (Volcanic Ash Advisory Center), London, has continuously published graphics of the predicted spread and dispersion of the volcanic ash plume, which were partly basis for the air traffic restrictions in Germany. In this situation the Laboratory for Environmental Measurement Techniques of the University of Applied Sciences in Duesseldorf has performed 14 measurement flights starting from April 23 2010 to May 21 2010 to get real airborne in-situ dust measurement data over the north-western part of Germany and for comparison with the predicted ash dispersion model data of the VAAC of London in Germany. Moreover, airborne passive DOAS remote sensing measurements have been performed by a mini-DOAS system for SO2-measurements within the plume. In this paper the results of the airborne optical ash particle measurements as well as the remote sensing SO2 measurements will be reported for situations with and without the volcanic plume over northern Germany in detail. Moreover, the measured dust data will be compared with the model dispersion predictions for the ash plume by the VAAC and with European limit concentrations. Main conclusions are: The „ash plume", found by the aircraft measurement of the Duesseldorf University of Applied Sciences over north western Germany in the "red zone" predicted by the VAAC turned out to be inhomogeneous during the measurement flights Clusters of ash plume sometimes had only a height extension of several hundred meters or less Ash substructures with a horizontal extension of ten kilometres up to several tenth of kilometres could be found Vertical double structures of ash plume could be measured by spiral flights and could be observed visually in horizontal direction Ash plume could be observed visually as small brown layer in horizontal direction Particles collected during flight could be identified as ash particles by electron microscope analysis and chemical analysis}, subject = {Vulkanasche}, language = {en} } @article{WeberHewelingFischeretal.2017, author = {Weber, Konradin and Heweling, Georg and Fischer, Christian and Lange, Martin}, title = {The use of an octocopter UAV for the determination of air pollutants - a case study of the traffic induced pollution plume around a river bridge in Duesseldorf, Germany}, series = {International Journal of Environmental Science}, volume = {2}, journal = {International Journal of Environmental Science}, issn = {2367-8941}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50805}, pages = {63 -- 66}, year = {2017}, abstract = {Emissions of air pollutants from the road traffic are still a major problem in Germany. It is well known that traffic induced fine particulate matter (PM10, PM2.5, PM1), ultrafine particles (UFPs) and gaseous air pollutants, like e.g. NOx, are adverse to human health. Therefore it is important to monitor these air pollutants in the cities. In this study an octocopter UAV is used as a carrier for measurement systems for UFPs, fine particulate matter and soot. This instrumented octocopter was used for studying the vertical and horizontal variation of the air pollution plume, which originated from the traffic on a river bridge, connecting two parts of Duesseldorf in Germany. This octocopter UAV had been especially designed and built at the Duesseldorf University of Applied Sciences for measurements of air pollutants. It was featuring eight 900 W electric propeller drives and was equipped with a pixhawk flight control. Its lift off weight was about 10.5 kg. About 60 measurement flights were performed by the instrumented octocopter throughout this study. These measurement flights could clearly determine the traffic induced air pollution plume originating from the bridge. Moreover, the dispersion of UFPs within the pollution plume could be monitored with the octocopter flights.}, subject = {Flugk{\"o}rper}, language = {en} } @inproceedings{VogelWeberEliassonetal.2012, author = {Vogel, Andreas and Weber, Konradin and Eliasson, Jonas and Palsson, Asgeir and Moser, H. M. and Palsson, Thorgeir and von L{\"o}wis, S. and Fischer, Christian}, title = {Airborne and groundbased measurements of ash particles on Iceland and over Germany during the Gr{\´i}msv{\"o}tn eruption May 2011 [Abstract]}, series = {Geophysical Research Abstracts:EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria}, booktitle = {Geophysical Research Abstracts:EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria}, publisher = {Copernicus}, address = {G{\"o}ttingen}, pages = {12854}, year = {2012}, abstract = {The eruption of the Grimsv{\"o}tn volcano in May 2010 posed with its ash plume a thread to the aviation in northern Europe. Because of ash plume forecasts of the VAAC London the airport of Keflavik in Iceland as well as airports in England, Scotland and Scandinavia were closed for some time, which caused the cancellation or change of about 500 flights in Europe. Even in Germany the airports of Bremen, Hamburg and Berlin were closed for several hours on 25 May 2011. During this eruption period in May 2011, a team of the Duesseldorf University of Applied Sciences, the University of Iceland, the University of Reykjavik and the IMO has performed airborne in-situ measurements over Iceland and Germany as well as ground based measurements in the south of Iceland. The ground based measurements were performed continuously during the whole eruption period at two significant positions (Skogar and Hvollsv{\"o}llur) with optical particle counters (OPCs). The measurement method was based on measuring the airborne concentrations of the classic aerosol components (PM10, PM2.5 and PM1) and TSP (total suspended particles) every 6 seconds. Additional measurement flights on Iceland were started already one day after the beginning of the eruption (twelve in-situ measurement flights) and marked the spatial and temporal spread of volcanic ash in the atmosphere. For the flights light slow flying piston engine powered airplanes where used. The flights over Iceland focused on the western part of Iceland in the region of Reykjavik and Keflavik and over the international airport in Keflavik and were mostly coordinated by ISAVIA. The measurement flights helped to keep Keflavik International Airport open for many additional hours despite of adverse predictions by the London VAAC model, because it was possible to observe the particle concentration on-line during the flights. In Germany a measurement flight was performed on 25 May 2012 over the northern part of Germany where the volcanic ash cloud was forecasted from the dispersion model of the London VAAC. This flight was performed on the behalf of the German Weather Service (DWD). The measurement flights revealed most time relative low airborne ash concentrations over western Iceland, although the groundbased measured ash concentrations in the south of Iceland nearer to the Grimsv{\"o}tn were very high. In Germany the measured concentrations during the flight were low enough to be consistent with the re-opening of the airports Bremen, Hamburg and Berlin, which were closed by the authorities for several hours on 25 May 2011 because of high concentration predictions by the VAAC-model. The measurement flights clearly proved that OPCs, based on slow flying piston-motor driven aircrafts, are very suitable for the determination of airborne ash particles during volcanic eruptions. This is an important issue for air traffic safety.}, language = {en} } @inproceedings{GonzalezRialDinardoPadillaetal.2024, author = {Gonz{\´a}lez Rial, Gabriel and Dinardo, Daniel and Padilla, Germ{\´a}n D. and Barrancos, Jos{\´e} and Hern{\´a}ndez, Pedro A. and P{\´e}rez, Nemesio M. and Weber, Konradin and Fischer, Christian and Amend, Detlef}, title = {Remake of the low cost carbon dioxide sensor of the carbon dioxide network deployed by INVOLCAN in the urban areas of Puerto Naos and La Bombilla, La Palma, Canary Islands}, series = {European Geosciences Union General Assembly 2024, Vienna, Austria, 14-19 Apr 2024}, booktitle = {European Geosciences Union General Assembly 2024, Vienna, Austria, 14-19 Apr 2024}, number = {EGU24-19641}, publisher = {Copernicus}, doi = {10.5194/egusphere-egu24-19641}, year = {2024}, abstract = {An anomalous CO2 degassing appeared by the end of Tajogaite eruption (North-West flank of Cumbre Vieja volcano ridge, La Palma, Canary Islands), in the neighborhoods of La Bombilla and Puerto Naos at about 6 km distance from the volcanic vent. The areas affected by the anomalous CO2 degassing were not directly affected by lava flows during the eruptive period. After the eruption, and due to this strong volcanic-hydrothermal carbon dioxide emissions (CO2 5-20\%) were included in the exclusion zone. CO2 is an invisible toxic gas, as well as asphyxiating, and may be lethal when is present in concentrations higher than 14\%. During the post-eruptive period, INVOLCAN deployed its own indoor and outdoor CO2 monitoring networks in collaboration with other institutions, with the aim of delimitating the anomalous CO2 degassing areas, paying attention to those areas where CO2 air concentration exceeds hazardous thresholds. The number of monitoring stations were increasing to cover most of the homes, garages, basements, and local businesses. The first monitoring network were based on a LILYGO; TTGO T-SIM7000G electroniccard, previously programmed with an unstable algorithm that caused problems during the measurements. After some implementations to enhance the stability of the sensor, a new algorithm was developed that consists of the acquisition of ambient values every 5 seconds, applying a Moving Average Filter in every measurement to avoid outliers. The SIM card integrated in the hardware allows the data transmission to an MQTT broker where the values are published every 5 minutes, recollecting them in a unique Raspberry Pi 4 Model B located at the INVOLCAN headquarters, that reads and stores the data in two databases (InfluxDB and Google Sheets). The visualization of the values are done through Grafana Cloud, recollecting the data from InfluxDB and showing them distributed as tables and a geographic map that illustrates the concentration in the measurement points. The difference between this and the last storing is the flexibility when visualizing the data, that can be transformed to different kind of plots as mentioned. Moreover, an API for the management of each subsystem is created using PyQT, allowing to the user the calibration of the sensors in remote, as well as executing a soft reboot, or the integration of deeper parameters like the sensor mode (manual polling, streaming or command mode) or pressure data. Two of the 20 devices have been successfully installed and they are working correctly in La Palma, meanwhile an amount of 18 devices are being tested and recollecting properly with better stability in CO2 concentration measurements at our laboratory and will be installed indoor in different locations soon. The remaking of the algorithm allows to forget previous problems of wrong data and disconnections, obtaining accurate data compared to commercial sensors and helping the operator to configure and control the sensors without moving to conflicting locations.}, subject = {Vortrag}, language = {en} } @article{WeberFischerPohletal.2015, author = {Weber, Konradin and Fischer, Christian and Pohl, Tobias and B{\"o}hlke, Christoph and Lange, Martin and Scharifi, Emad and Eliasson, Jonas and Yoshitani, Junichi}, title = {The Application of Light Research Aircraft for the Investigation of Volcano Eruption Plumes, Industrial Emissions and Urban Plumes}, series = {WSEAS Transactions on Environment and Development}, volume = {11}, journal = {WSEAS Transactions on Environment and Development}, publisher = {WSEAS}, issn = {2224-3496}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50892}, pages = {89 -- 94}, year = {2015}, abstract = {Airborne measurements have proved to be an important tool for the investigation of volcanic emission plumes, industrial pollution plumes, fugitive emissions and urban pollution plumes. In this paper several examples are demonstrated, how these investigations can be performed by light and microlight propeller aircraft. Throughout the last years innovative aircraft were developed in the light and microlight class showing an excellent flight performance. This enables airborne measurements, which were performed in former years normally by big jet engine driven research aircraft. Moreover, these light and microlight aircraft are equipped with piston motors, which are sturdy enough to operate even in adverse and harsh flight conditions, e.g. in volcanic plumes with high ash concentration. Additionally, turbo charged versions of these airborne piston motors are available, which allow flight altitudes of 7000m - 9000m enabling a large variety of research missions. Another advantage of light and microlight research aircraft is that they are quite cost effective and have a comparatively short certification process for the installation of new measurement equipment. This made it possible to respond fast to the eruption of the Icelandic volcano Eyjafjallaj{\"o}kull 2010 and Grimsv{\"o}tn 2011 with research flights in volcanic ash plumes over Germany and Iceland. In this way it was possible to deliver real airborne measurements additional to the ash plume model calculations of the London Volcanic Ash Advisory Center (VAAC). In this paper examples of airborne measurements in the volcanic plumes of the recent eruptions of Icelandic volcanoes are given. Moreover examples are presented, which highlight the outstanding capabilities of these aircraft for pinpointing industrial emissions and for characterizing urban pollution plumes.}, subject = {Vulkanismus}, language = {en} } @article{PohlFischerHewelingetal.2017, author = {Pohl, Tobias and Fischer, Christian and Heweling, Georg and B{\"o}hlke, Christoph and Weber, Konradin}, title = {A Comparative Study as a Quality Assurance of Stationary and Portable Hand-Held Ultrafine Particle Monitors}, series = {WSEAS Transactions on Environment and Development}, volume = {13}, journal = {WSEAS Transactions on Environment and Development}, publisher = {WSEAS}, issn = {2224-3496}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50799}, pages = {6}, year = {2017}, abstract = {In this study we investigated the performance of two portable hand-held measurement devices (Testo DiSCMini, Grimm NanoCheck) under real environmental conditions at an area on the new campus of the University of Applied Sciences Duesseldorf, which was influenced by construction activities and traffic. The values were compared to the data from a freshly calibrated SMPS (Grimm SMPS+C) as a reference system. The SMPS measured the particle number concentration as well as the particle number size distribution in a range from 5 nm to 350 nm. This was done as a quality assurance for the use of these portable devices for other measurement campaigns for detecting the particle number concentration in mobile applications by e.g. unmanned aerial systems, bicycles, or small aircraft. The results show a good correlation between all the systems. The agreement between the reference system and the NanoCheck was really good, but lower between the DiSCMini and the reference system. Due to the good correlation the data could be post processed with a correction function to reduce the deviation. Finally, it can be stated, that both systems work well under environmental conditions and are well suited for the mobile use for the investigation of ultrafine particle concentration.}, subject = {Messtechnik}, language = {en} }