Airborne observations in multidisciplinary environmental research using European Research Infrastructures; observations, campaigns and future plans

Observations from aircraft, remotely piloted aircraft systems (RPAS/UAV/UAS) and balloons are an important means to obtain a broad view of processes within the Earth environment during measurement campaigns. The range of available instruments enables a broad and flexible range of applications. It includes sensors for meteorological parameters, trace gases and cloud/aerosol particles and more complex systems like high spectral resolution lidar, hyperspectral imaging at wavelengths from the visible to thermal infra-red and synthetic aperture radar. The use of small state-of-the-art instruments, the combination of more and more complex sets of instruments with improved accuracy and data acquisition speed enables more complex campaign strategies even on small aircraft, balloons or RPASs.
Applications include atmospheric parameters, surface properties of vegetation, glaciological processes, sea ice and iceberg studies, soil and minerals and dissolved or suspended matter in inland water and the ocean. Ground based systems and satellites are key information sources to complement airborne datasets and a comprehensive view of the observed system is often obtained by combining all three. Aircraft and balloon operations depend on weather conditions either to obtain the atmospheric phenomenon of interest or the required surface-viewing conditions and so require detailed planning. They cover large areas in the horizontal and vertical with adaptable temporal sampling. Future satellite instruments can be tested using airborne platforms during their development. The validation of operational satellite systems and applications using airborne measurements has come increasingly into focus with the European Copernicus program in recent years.
This session will bring together aircraft, balloon and RPAS operators and the research community to present:
• an overview of the current status of environmental research with a focus on the use of airborne platforms
• recent observation campaigns and their outcomes
• multi-aircraft/balloon/RPAS and multi-RI campaigns
• using airborne and ground-based RI to complement satellite data, including cal/val campaigns
• identifying and closing capability gaps
• contributions of airborne measurements to modelling activities
• airborne platforms to reduce the environmental footprint of alternative observation strategies
• airborne instruments, developments and observations
• future plans involving airborne observational research

Public information:
Observations from aircraft, remotely piloted aircraft systems (RPAS/UAV/UAS) and balloons are an important means to obtain a broad view of processes within the Earth environment during measurement campaigns. The range of available instruments enables a broad and flexible range of applications. It includes sensors for meteorological parameters, trace gases and cloud/aerosol particles and more complex systems like high spectral resolution lidar, hyperspectral imaging at wavelengths from the visible to thermal infra-red and synthetic aperture radar. The use of small state-of-the-art instruments, the combination of more and more complex sets of instruments with improved accuracy and data acquisition speed enables more complex campaign strategies even on small aircraft, balloons or RPASs.
Applications include atmospheric parameters, surface properties of vegetation, glaciological processes, sea ice and iceberg studies, soil and minerals and dissolved or suspended matter in inland water and the ocean. Ground based systems and satellites are key information sources to complement airborne datasets and a comprehensive view of the observed system is often obtained by combining all three. Aircraft and balloon operations depend on weather conditions either to obtain the atmospheric phenomenon of interest or the required surface-viewing conditions and so require detailed planning. They cover large areas in the horizontal and vertical with adaptable temporal sampling. Future satellite instruments can be tested using airborne platforms during their development. The validation of operational satellite systems and applications using airborne measurements has come increasingly into focus with the European Copernicus program in recent years.
Co-organized by AS5/BG2
Convener: Thomas Ruhtz | Co-conveners: Sven Fahrner, Paola Formenti, Felix Friedl-Vallon, Shridhar JawakECSECS
vPICO presentations
| Fri, 30 Apr, 13:30–16:15 (CEST)
Public information:
Observations from aircraft, remotely piloted aircraft systems (RPAS/UAV/UAS) and balloons are an important means to obtain a broad view of processes within the Earth environment during measurement campaigns. The range of available instruments enables a broad and flexible range of applications. It includes sensors for meteorological parameters, trace gases and cloud/aerosol particles and more complex systems like high spectral resolution lidar, hyperspectral imaging at wavelengths from the visible to thermal infra-red and synthetic aperture radar. The use of small state-of-the-art instruments, the combination of more and more complex sets of instruments with improved accuracy and data acquisition speed enables more complex campaign strategies even on small aircraft, balloons or RPASs.
Applications include atmospheric parameters, surface properties of vegetation, glaciological processes, sea ice and iceberg studies, soil and minerals and dissolved or suspended matter in inland water and the ocean. Ground based systems and satellites are key information sources to complement airborne datasets and a comprehensive view of the observed system is often obtained by combining all three. Aircraft and balloon operations depend on weather conditions either to obtain the atmospheric phenomenon of interest or the required surface-viewing conditions and so require detailed planning. They cover large areas in the horizontal and vertical with adaptable temporal sampling. Future satellite instruments can be tested using airborne platforms during their development. The validation of operational satellite systems and applications using airborne measurements has come increasingly into focus with the European Copernicus program in recent years.

vPICO presentations: Fri, 30 Apr

Chairpersons: Thomas Ruhtz, Paola Formenti
Airborne Research Infrastructure
Philip Brown and Elisabeth Gerard

Since its creation in 2000, the European Facility for Airborne Research, EUFAR, evolved into the central network for the airborne research community in Europe. From the beginning until 2018, EUFAR has received funding within the different Framework Programmes of the European Commission. In January 2018, EUFAR became an AISBL (international non-profit association under Belgian law) establishing EUFAR as an independent legal structure and ensuring EUFAR’s future.

Via EUFAR Transnational Access, a range of aircraft and instrumentation has been made available to European researchers who do not have access to a suitable research infrastructure in their home country. This has provided both a comprehensive range of atmospheric in-situ measurements together with a variety of remote-sensing instruments and hyperspectral imagers for studies of land or water surfaces, vegetation etc. Examples of successful TA activities will be shown. In order that researchers should continue in future to have access to the most appropriate research aircraft and instrumentation to meet their science objectives independently of EC funding, EUFAR is now working to develop principles of Open Access (OA).

EUFAR supports Expert Working Group meetings to exchange knowledge and promote best practice across the range of activities involved in airborne research. These cover, for example, instrument developments, data processing software and the scientific uses of airborne data. Via its previous EC funding, EUFAR has been able to support training courses for early-career researchers to introduce them to the use of airborne measurements for environmental research. Where possible, new software tools resulting from these activities are provided openly via the EUFAR website. EUFAR also promotes access to its members' data from airborne platforms and instruments and will be working with the AERIS data centre in France to provide a data portal to assist with this.

This presentation will give an overview of EUFAR, its recent achievements and future plans.

How to cite: Brown, P. and Gerard, E.: EUFAR: the European Facility for Airborne Research, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15741,, 2021.

Felix Friedl-Vallon, Philippe Raizonville, André Vargas, Kristine Dannenberg, Marta Albano, Rainer Kirchhartz, Eric Vachon, Mattias Abrahamsson, Kjell Boen, Xavier Dubois, Nathalie Huret, Neil Harris, Pietro Ubertini, and Klaus Pfeilsticker

Stratospheric balloons are useful platforms for various research and technology needs. They allow to collect valuable data in many science fields, e.g. atmospheric science and astrophysics; they can be used for demonstrations in preparation of new space and Earth observation missions; they can be used to provide calibration/validation data for Earth observation space missions, or for dropping test objects from the stratosphere.

Various types of balloons are available, corresponding to different missions: Zero Pressure Balloons (ZPB) for heavy payloads (100 kg to 3 tons) and short to medium duration (1 day to several days), Sounding Balloons (SB) for very light payloads (3 kg).

Payloads can be flown at various altitudes between the ground surface up to 40 km, according the type of balloon and the kind of mission. Compared to satellites, stratospheric balloons can be operated at relatively low cost and with shorter lead times from the experiment idea to the flight.

Mid-2017, a new Research Infrastructure called HEMERA has been selected by the European Commission within its programme Horizon 2020. The HEMERA objectives are to:

  • Provide better and coordinated balloon access to the troposphere and stratosphere for scientific and technological research, in response to the scientific user needs.
  • Attract new users to enlarge the community accessing the balloon infrastructure and foster scientific and technical collaboration.
  • Enlarge the fields of science and technology research conducted with balloons.
  • Improve the balloon service offered to scientific and technical users through innovative developments.
  • Favour standardization, synergy, complementarities and industrialization through joint developments with greater cost-effectiveness.

The project is coordinated by CNES and involves 13 partners in total, from various European entities and Canada. The project was kicked-off in late January 2018 and will be executed during 2018-2022.

Six ZPB flights with a target payload mass of at least 150 kg are foreseen within HEMERA, offering free of charge access to users and scientists for various science measurements and/or for technology tests. In addition, several SB flights are foreseen. The launch sites will be Esrange in Sweden, Timmins in Canada, for the ZPB and Aire sur l'Adour in France for the SB. The selected experiments will fly on balloons during the years 2019-2022. 

Two Calls for Proposals were planned in the HEMERA project, the first was launched in 2018 and 39 answers from 12 countries have been received; 23 experiments have been selected. 31 answers have been received in the frame of the second call, from 10 countries. In total 39 experiments from 13 countries have been selected. The first HEMERA flights occurred in summer 2019 from Kiruna and Timmins.

In addition, Open Access to balloon data will be organized in the frame of the Data Center, giving access to science data collected during the flights. Networking activities are planned in order to promote the Infrastructure in the European countries, and Joint Research activities are conducted in order to improve as far as possible the balloon offer in the view of the user needs.

How to cite: Friedl-Vallon, F., Raizonville, P., Vargas, A., Dannenberg, K., Albano, M., Kirchhartz, R., Vachon, E., Abrahamsson, M., Boen, K., Dubois, X., Huret, N., Harris, N., Ubertini, P., and Pfeilsticker, K.: The HEMERA Balloon Research Infrastructure, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13035,, 2021.

Hannah Clark and Iagos Team

IAGOS (In-service Aircraft for a Global Observing System) is a European Research Infrastructure for global observations of atmospheric composition using commercial aircraft. Commercial aircraft are ideal platforms for providing long-term in-situ measurements with high vertical and temporal resolution, particularly at cruise altitude (between 9 and 13 km) in the climate-sensitive region of the atmosphere known as the upper troposphere-lower stratosphere (UTLS). IAGOS also provides landing and take-off profiles at almost 300 airports throughout the world which are of major interest for air quality issues. Fully automated instruments are permanently installed on Airbus A330 aircraft operated by different airlines. Data are collected on about 500 flights per aircraft per year. All the aircraft measure the abundances of many essential climate variables, chiefly ozone and the precursor carbon monoxide, water vapour, clouds and meteorological parameters. Additional instruments can be installed to measure nitrogen oxides, aerosols, or the greenhouse gases carbon dioxide and methane. The data are transmitted in near to real real time to weather services and are freely available for the scientific community, national air quality prediction centres and the Copernicus Atmosphere Monitoring Service (CAMS). We describe the importance of these measurements in the monitoring of global atmospheric composition and air quality. In particular, we show examples from the Copernicus Atmosphere Monitoring Service (CAMS) where IAGOS data are used in the evaluation and improvement of forecasts of air quality over Europe, and discuss how the development of the IAGOS data transmission and instrumentation may fertilize infrastructure development for other airborne platforms.

How to cite: Clark, H. and Team, I.: The IAGOS Research Infrastructure for monitoring atmospheric composition and air quality using commercial aircraft, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1269,, 2021.

Shridhar Jawak, Agnar Sivertsen, Veijo Pohjola, Małgorzata Błaszczyk, Jack Kohler, Hans Tømmervik, Lennart Nilsen, Marta Majerska, Thomas Kræmer, Maarten J.J.E. Loonen, Janne Søreide, Dariusz Ignatiuk, Øystein Godøy, Inger Jennings, Christiane Hübner, and Heikki Lihavainen

Svalbard Integrated Arctic Earth Observing System (SIOS) is an international collaboration of 24 research institutions from 9 countries studying the environment and climate in and around Svalbard. The global pandemic of Coronavirus disease (Covid-19) has affected the Svalbard research in a number of ways due to nationwide lockdown in many countries, strict travel restrictions in Svalbard, and quarantine regulations. Many field campaigns to Svalbard were cancelled in 2020 and campaigns in 2021 are still uncertain. In response to this challenge, we conducted practical activities to support the Svalbard science community in filling gaps in scientific observations. One of our activities involved conducting airborne remote sensing campaigns in Svalbard to support scientific projects. In 2020, SIOS supported 10 scientific projects by conducting 25 hours of aircraft and unmanned aerial vehicle (UAV)-based data collection in Svalbard. This is one of the finest ways to fill the data gap in the current situation as it is practically possible to conduct field campaigns using airborne platforms in spite of travel restrictions. We are using the aerial camera and hyperspectral sensor installed onboard the Dornier DO228 aircraft operated by the local company Lufttransport to acquire aerial images and hyperspectral data from various locations in Svalbard. The hyperspectral sensor image the ground in 186 spectral bands covering the range 400-1000 nm. Hyperspectral data can be used to map and characterise earth, ice and ocean surface features, such as minerals, vegetation, glaciers and snow cover, colour and pollutants. Further, it can be used to make 3D models of the terrain as well as searching for the presence of animals (e.g. counting seals). In addition, aerial photos are particularly useful tool to follow the seasonal dynamic changes and extent in sea ice cover, tracking icebergs, ocean productivity (Chlorophyll a) and river runoff (turbidity). Data collected from the SIOS funded airborne missions will not only help to fill a few of the data gaps resulting from the lockdown but also will be used by glaciologists, biologists, hydrologists, and other Earth system scientists to understand the state of the environment of Svalbard during these times. In 2021, we are continuing this activity by conducting more airborne campaigns in Svalbard. In this presentation, we will specifically focus on the overview of projects supported by airborne remote sensing campaigns.

How to cite: Jawak, S., Sivertsen, A., Pohjola, V., Błaszczyk, M., Kohler, J., Tømmervik, H., Nilsen, L., Majerska, M., Kræmer, T., Loonen, M. J. J. E., Søreide, J., Ignatiuk, D., Godøy, Ø., Jennings, I., Hübner, C., and Lihavainen, H.: SIOS’s airborne remote sensing campaigns in Svalbard , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9129,, 2021.

Airborne Instrumentation
RPAS Instruments
Maximilien Desservettaz, Christos Keleshis, Panayiota Antoniou, Panagiotis Vouterakos, Yunsong Liu, Christos Constantinides, Agapios Agapiou, Roland Sarda-Esteve, Dominique Baisne, Greg Kok, and Jean Sciare

The Cooperation to Unravel the Role of the Atmospheric Aerosol over the Amazon Basin using drones (CURE-3AB) project has yielded new technical solutions to perform high quality in-situ atmospheric observations in the lower troposphere (0-2 km) with Unmanned Aerial Vehicles (UAVs). An Ozonesonde (EN-SCI ECC, Model 2Z), designed for regular O3 radio sounding, has been adapted to perform on-line measurements of Ozone onboard the drone. A 3D printed low-cost pollen/spore collector has been developed to replicate reference instruments (VPPS2000) and adapted to perform onboard our UAV. Finally, an optical particle counter (AlphaSense) and a custom-made drying system have been fitted on a third drone. The three vehicle/instrument tandems will be deployed in the proximity of the Amazonian Tall Tower Observatory during the CURE-3AB campaign (delayed due to pandemic). We present the instrumental developments, setups, and preliminary test results performed with our UAVs at the Cyprus Institute private airspace.

How to cite: Desservettaz, M., Keleshis, C., Antoniou, P., Vouterakos, P., Liu, Y., Constantinides, C., Agapiou, A., Sarda-Esteve, R., Baisne, D., Kok, G., and Sciare, J.: Development and adaptation of sensors and samplers for vertical profiling using fixed-wing drones in the context of the Cooperation to Unravel the RolE of Atmospheric Aerosols over the Amazonian Basin (CURE-3AB)., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12966,, 2021.

Maximilian Reuter, Heinrich Bovensmann, Michael Buchwitz, Jakob Borchard, Sven Krautwurst, Konstantin Gerilowski, and John P. Burrows

A reduction of the anthropogenic emissions of CO2 (carbon dioxide) is necessary to stop or slow down man-made climate change. To verify mitigation strategies, a global monitoring system such as the envisaged European Copernicus anthropogenic CO2 monitoring mission (CO2M) is required. Those satellite data are going to be complemented and validated with airborne measurements. UAV (unmanned aerial vehicle) based measurements can provide a cost-effective way to contribute to these activities. Here we present the development of a sUAS (small unmanned aircraft system) to quantify the CO2 emissions of a nearby point source from its downwind mass flux without the need for any ancillary data. Specifically, CO2 is measured by an in situ NDIR (non-dispersive infrared) detector and the wind speed and direction is measured with a 2D ultrasonic acoustic resonance anemometer. In order to minimize the effect of rotor downwash, we calibrate the anemometer by analyzing wind measurements taken while following a suitable flight pattern and assuming stationary wind conditions. We quantify the quality of the CO2 and wind measurements with an in-flight validation at the ICOS (Integrated Carbon Observation System) atmospheric station Steinkimmen (STE) near Bremen, Germany. By means of two flights downwind of the ExxonMobil natural gas processing facility in Großenkneten about 40km east of Bremen, Germany, we demonstrate how the measurements of elevated CO2 concentrations can be used to infer mass fluxes of atmospheric CO2 related to the emissions of the facility.

How to cite: Reuter, M., Bovensmann, H., Buchwitz, M., Borchard, J., Krautwurst, S., Gerilowski, K., and Burrows, J. P.: Development of a small unmanned aircraft system to derive CO2 emissions of anthropogenic point sources, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8465,, 2021.

Balloon Instruments
Erik Kretschmer, Felix Friedl-Vallon, Thomas Gulde, Michael Höpfner, Sören Johansson, Anne Kleinert, Guido Maucher, Tom Neubert, Hans Nordmeyer, Christof Piesch, Peter Preusse, Martin Riese, Georg Schardt, Axel Schönfeld, Jörn Ungermann, and Gerald Wetzel

The GLORIA-B (Gimballed Limb Observer for Radiance Imaging of the Atmosphere - Balloon) instrument is an adaptation of the very successful GLORIA-AB imaging Fourier transform spectrometer (iFTS) flown on the research aircrafts HALO and M55 Geophysica. The high spectral resolution in the LWIR (Long Wave Infrared) allows for the retrieval of temperature and of a broad range of atmospheric trace gases, with the goal to retrieve O3, H2O, HNO3, C2H6, C2H2, HCOOH, CCl4, PAN, ClONO2, CFC-11, CFC-12, SF6, OCS, NH3, HCN, BrONO2, HO2NO2, N2O5 and NO2. The radiometric sensitivity of the Balloon instrument is further increased in comparison with the GLORIA-AB instrument by having two detector channels on the same focal plane array, while keeping the same concept of a cooled optical system. This system improvement was achieved with minimal adaptation of the existing optical system.

The high spatial and temporal resolution of the instrument is ensured by the imaging capability of the Fourier transform spectrometer while stabilizing the line-of-sight in elevation with the instrument and in azimuth with the balloon gondola. In a single measurement lasting 13 seconds, the atmosphere can be sounded from mid-troposphere up to flight altitude, typically 30 km, with a vertical resolution always better than 1 km for most retrieved species; a spatial resolution up to 0.3 km can be achieved in favourable conditions. Temperature retrieval precision between 0.1 and 0.2 K is expected. A spectral sampling up to 0.0625 cm-1 can be achieved.

The first flight of GLORIA-B shall take place during the late-summer polar jet turn-around at Kiruna/ESRANGE. This flight is organised in the frame of the HEMERA project and was scheduled for summer 2020, but was ultimately postponed to summer 2021. Beyond qualification of the first balloon-borne iFTS, the scientific goals of the flight are, among others, the quantification of the stratospheric bromine budget and its diurnal evolution by measuring vertical profiles of BrONO2 in combination with BrO observations by the DOAS instrument of University Heidelberg on the same platform.

How to cite: Kretschmer, E., Friedl-Vallon, F., Gulde, T., Höpfner, M., Johansson, S., Kleinert, A., Maucher, G., Neubert, T., Nordmeyer, H., Piesch, C., Preusse, P., Riese, M., Schardt, G., Schönfeld, A., Ungermann, J., and Wetzel, G.: Balloon-borne GLORIA hyperspectral Limb and Nadir imager in the LWIR, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11674,, 2021.

Martin Wienold, Alexey Semenov, Heiko Richter, and Heinz-Wilhelm Hübers

The Oxygen Spectrometer for Atmospheric Science on a Balloon (OSAS-B) is dedicated to the remote sounding of atomic oxygen in the mesosphere and lower thermosphere (MLT) region of Earth's atmosphere, where atomic oxygen is the dominant species. Quantitative radiometry of atomic oxygen via its visible and near-infrared transitions has been difficult, due to the complex excitation physics involved. OSAS-B is a heterodyne spectrometer for the thermally excited ground state transition of atomic oxygen at 4.75 THz. It will enable spectrally resolved measurements of the line shape,  which in turn enables the determination of the concentration of atomic oxygen in the MLT. Due to water absorption, this line can only be observed from high-altitude platforms such as a high-flying airplanes, balloons or satellites. Recently the first spectrally resolved observation of the 4.75-THz line has been reported using a heterodyne spectrometer on SOFIA, the Stratospheric Observatory for Infrared Astronomy [1]. Compared to SOFIA a balloon-borne instrument has the advantage of not being hampered by atmospheric water vapor absorption. OSAS-B will comprise a hot-electron bolometer mixer and a quantum-cascade laser as local oscillator in a combined helium/nitrogen dewar. A turning mirror will allow for sounding at different vertical inclinations. The  first flight of OSAS-B is planned for autumn 2022 in the frame of the European HEMERA project [2].

[1] H. Richter et al., Direct measurements of atomic oxygen in the mesosphere and lower thermosphere using terahertz heterodyne spectroscopy, accepted for publication in Communications Earth & Environment (2021).


How to cite: Wienold, M., Semenov, A., Richter, H., and Hübers, H.-W.: OSAS-B: a balloon-borne heterodyne spectrometer for sounding atomic oxygen in the MLT region, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10874,, 2021.

Daniel Letros, Adam Bourassa, Paul Loewen, Liam Graham, Nick Lloyd, Landon Rieger, and Doug Degenstein

The Aerosol Limb Imager (ALI) is a multi-spectral imager capable designed to observe aerosol extinction and particle size profiles in the upper-troposphere lower-stratosphere. ALI uses a system of linear polarizers, a liquid crystal rotator, and an acoustic-optic tunable filter to select the linear polarization state and wavelength of limb scattered sunlight radiance between 600 nm and 1500 nm. From stratospheric balloon, spectral images have spatial resolution of <100 meters at the tangent point, and can produce useful aerosol observations between 5 km and 30 km in altitude. Of novelty is the polarimetric capability of ALI, which uses the orthogonal polarization states to detect cloud in the spectral data and facilitate its distinction from aerosol. Two previous iterations of the ALI instrument concept have already been successfully demonstrated, once in 2014 and again in 2018. Currently, a third iteration is being developed which improves upon the thermal, structural, and optical performance of the previous iterations. This improved iteration is scheduled for demonstration as part of the HEMERA program out of Kiruna, Sweden in the summer of 2021. This demonstration serves the larger objective of further proving the engineering and scientific readiness of the ALI instrument concept for eventual high-altitude aircraft and satellite platform deployments.  ALI is a proposed Canadian contribution to the NASA A-CCP satellite mission study.

How to cite: Letros, D., Bourassa, A., Loewen, P., Graham, L., Lloyd, N., Rieger, L., and Degenstein, D.: Improved multi-spectral polarimetric observations of UTLS aerosol and cloud from stratospheric balloon with the Aerosol Limb Imager, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6714,, 2021.

Paolo Tealdi, Fabrizio Innocenti, and Giovanni (John) Aimo

infoBalloons 2.0 is a selected Sounding Balloon (SB) Experiments in the 2nd HEMERA Call for Proposals (HEMERA H2020. This project has received funding from the European Union's Horizon 2020 research and Innovation programme under grant agreement No 730970).

This is a solution (self-made app/software and budget friendly IoT sensors and TC/TM communication link) to collect and then analyze data regarding atmospheric sounding, flight info/data and LPWAN (Low Power Wide Area Network) performances during a stratospheric balloon flight. Optional also to take POV photos/video of the flight.

infoBalloons 2.0 is the natural evolution of infoBalloons. The old 1.0 system reports a bunch of environmental data to an Android self-made app (available on Google Play for free) being carried in the hot air balloons using budget friendly industrial IoT sensors called Blebricks. IoT sensors communicate with the Android app installed inside the pilote’s smartphone using Bluetooth protocol and then the app partially elaborates the data and transmits them into the cloud (iSENSE platform) using a data (3G/4G) connection. infoBalloons was used several times during test flights and also for example during the International Hot Air Balloons Meeting in Mondovì in January 2019; it was developed by a group of Scientific High School students (I.I.S. “Cigna-Baruffi-Garelli” – Mondovì [Italy]) with the technical support of John Aimo Balloons - [Italy] (hot air balloons flights), Bleb Technology - [Italy] (Blebricks, the budget friendly industrial IoT sensors), iSENSE team (iSENSE is a web system for sharing and visualizing scientific data, based at the Engaging Computing Group at the University of Massachusetts Lowell [USA]) and MIT App Inventor team (CSAIL - Massachusetts Institute of Technology [USA]). The work was also presented in the Poster Session at last MIT App Inventor Summit 2019 in Cambridge, MA – USA.

How to cite: Tealdi, P., Innocenti, F., and Aimo, G. (.: infoBalloons: an Italian High School educational self-made budget friendly STEM experience with hot air/stratospheric balloons, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13420,, 2021.

Tom Neubert, Georg Schardt, Heinz Rongen, Egon Zimmermann, Thomas Gulde, Erik Kretschmer, Guido Maucher, Peter Preusse, Martin Riese, Jörn Ungermann, and Stefan van Waasen

Observations from aircraft and balloons with remote sensing instruments are an important method to investigate processes within the Earth environment. These applications require powerful computing systems that must be developed or adapted for the measurement task and requirements. In particular, imaging spectrometers generate high data rates by almost 10,000 pixels at about 4,000 frames per second. Accordingly, high performance is needed to provide operational control and data processing with high data bandwidth and the capability to store this data also during long duration flights.

A modular processing system architecture based on modified industrial grade board components has been developed to meet these high requirements for processing power and storage capacity. The major advantages of this approach are flexibility, (re)programmability, modularity and module re-use in order to attain lower development time and costs. However, it is a challenge to design this processing system to be suitable for the harsh environments of aircraft or balloon applications in terms of temperature range, humidity and vibration.

With an efficient approach ruggedized characteristics are achieved using a conduction cooled design in combination with components based on VPX standard and customized backplane transition modules in order to reduce operational risk with necessary measures of mitigation techniques. This approach results in a processing system that combines hardware and software redundancies to assure system availability and reliability for long duration flights.

In this presentation the compact flight proven system design is presented that has been used in recent years for high spectral resolution limb-observations by the GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) spectrometer aboard the HALO and Geophysica high-altitude aircrafts. Various system configurations and performance results will be shown, which have been achieved in the current design and will be applied in future balloon campaigns.

How to cite: Neubert, T., Schardt, G., Rongen, H., Zimmermann, E., Gulde, T., Kretschmer, E., Maucher, G., Preusse, P., Riese, M., Ungermann, J., and van Waasen, S.: High performance modular, compact and ruggedized processing system for airborne and balloon remote sensing instruments, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7447,, 2021.

Ralf Tillmann, Franz Rohrer, Georgios I. Gkatzelis, Benjamin Winter, Christian Wesolek, Tobias Schuldt, Morten Hundt, Oleg Aseev, and Astrid Kiendler-Scharr

A Zeppelin NT airship has been used as a platform for in-situ measurement of greenhouse gases and air pollutants in the planetary boundary layer (PBL). The Zeppelin especially with its long flight endurance, low air speed and potential high payload fills a gap between stationary ground based and remote sensing measurements, payload limited UAV based air monitoring, long range-high-altitude aircraft, and satellite observations. Its flight properties render unique applications for the observation of PBL dynamics and air quality monitoring. Highly resolved spatial and temporal trace gas measurements provide input required for modelling of air pollution and validation of emission inventories.

The core instrument deployed was a novel Quantum Cascade Laser (QCL) based multi-compound gas analyzer (MIRO Analytical AG) to measure in-situ concentrations of 10 greenhouse gases and air pollutants simultaneously. The analyzer measured CO2, N2O, H2O and CH4, and the pollutants CO, NO, NO2, O3, SO2 and NH3 with high precision and a measurement rate of 1 Hz. The instrument was operated remotely without the need of on-site personnel. The instrument package was complemented by electrochemical sensors for NO, NO2, Ox and CO (alphasense), an optical particle counter (alphasense), temperature, humidity, altitude and position monitoring. Three campaigns of two weeks each were conducted in 2020 comprising unattended operation during commercial passenger flights.

The acquired data set will be discussed in regard to (1) diurnal height profiles of trace gases such as NO2, (2) a detailed source attribution by fingerprinting, and (3) a comparison to observations from ground-based monitoring stations. The results demonstrate the QCL spectrometer as an all-in-one solution for air-borne trace gas monitoring. By measuring 10 compounds at once it helps to greatly reduce payload, space requirements and power consumption.

How to cite: Tillmann, R., Rohrer, F., Gkatzelis, G. I., Winter, B., Wesolek, C., Schuldt, T., Hundt, M., Aseev, O., and Kiendler-Scharr, A.: High-resolution air-quality observations onboard commercial Zeppelin flights in Germany , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6470,, 2021.

Aircraft Instruments
Joerg Brauchle, Tilman Bucher, Daniel Hein, Ralf Berger, Matthias Gessner, and Karsten Stebner

High resolution remote sensing under harsh environmental condition on special carriers requires instruments which are more flexible und more ruggedized than devices off the shelf. Particularly addressing environmental research in polar and high alpine regions, a family of cameras developed by the DLR is presented. The MACS systems are specifically made for the use on airborne platforms. Due to scalability, small sensors like single sensors on rugged fixed-wing UAVs can be realized. The configuration can be extended to RGB/NIR/TIR oblique viewing rigs with up to 5 coordinated cameras on manned aircraft. By processing such images, photogrammetric products like change detection, classification, elevation models and mapping mosaics are derived for regional areas. Further applications are the evaluation of algorithms in the field of AI for spaceborne imagery or the investigation of acquiring a particular combination of spectral bands.

These systems are able to deal with extreme illumination conditions and flight envelopes. Based on recent projects, the presentation shows examples and experiences, such as acquisition of the world’s highest glacier in Nepal, thermal infrared permafrost mapping of Ny Ålesund / Svalbard and sea ice measurements with a ground resolution of 3cm in the Fram Strait. Ideas for future sensors are indicated such as an UAV-based system with instant image transmission and a lightweight, high resolution sensor for stratospheric platforms.


How to cite: Brauchle, J., Bucher, T., Hein, D., Berger, R., Gessner, M., and Stebner, K.: Capabilities and Applications of MACS Aerial Camera Systems for Environmental Research, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16302,, 2021.

Katja Bigge, Udo Frieß, Denis Pöhler, and Ulrich Platt

Compared to ground-based or satellite measurements, atmospheric observations based on aircraft missions have many advantages, such as the potential to observe a large atmospheric volume using remote sensing measurements, among which Differential Optical Absorption Spectroscopy (DOAS) is a well established method for the observation of integrated trace gas concentrations along the light path. However, the interpretation of remote spectroscopic measurements using scattered sunlight is complicated due to the lack of prior knowledge on the light paths between sun and detector, and thus on the observed air volume. Using radiative transfer calculations, quantities commonly derived from DOAS measurements are integrated vertical columns of various trace gases, providing no information about their vertical distribution.

On the ground, tomographic approaches have been used to reconstruct the spatial distribution of trace gases by using multiple viewing directions and detectors. HAIDI, the Heidelberg Airborne Imaging DOAS Instrument, was designed to transfer this concept to the air. In addition to its excellent temporal and spatial resolution (40 m x 40 m at 1.5 km flight altitude, 266 m x 266 m at 10 km flight altitude, at 10 ms temporal resolution), HAIDI uses three separate scanning telescopes aimed at +/-45° forward- and backward looking angles and the nadir direction. In combination with a 3D radiative transfer model, this allows a reconstruction of the 3D distribution of the detected trace gases in the vicinity of the flight track.

HAIDI joined the EMerGe (Effect of Megacities on the Transport and transformation of Pollutants on the Regional to Global Scales) missions on HALO, the High Altitude and LOng range research aircraft based at DLR (German Aerospace Center) in Oberpfaffenhofen, Germany. The EMerGe missions targeted the emission outflows of megacities to investigate their compositions and the atmospheric impact of urban pollution in Europe (July 2017) and Asia (March 2018). HAIDI observed a number of trace gases such as NO2, SO2 and HCHO. For NO2 and SO2 in particular, strong plumes originating from power plants and ships were found, which were then used for inversion of the 3D distribution of the plume and emission estimation. Here we present the method and results of the HAIDI measurements during the EMeRGe missions.

How to cite: Bigge, K., Frieß, U., Pöhler, D., and Platt, U.: 3D Remote Sensing of Trace Gas Distributions with HAIDI (Heidelberg Airborne Imaging DOAS Instrument) - Power Plant and Ship Emissions observed during the EMeRGe Campaigns, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14336,, 2021.

Karolin Voss, Philip Holzbeck, Ralph Kleinschek, Robin Herlan, Katja Grossmann, Klaus Pfeilsticker, and André Butz

Spectroscopic direct sun remote sensing of the atmosphere offers an essential tool for determining atmospheric trace gas concentrations. The monitoring of ozone-depleting substances, such as halogen oxides in the middle atmosphere, contributes to observing the progress in restoring the ozone layer.

Here, we present a new compact solar occultation spectrometer for the UV/visible spectral range that can be mounted on stratospheric balloons such as deployed within the European HEMERA infrastructures. Due to its compactness, the instrument is suitable as a secondary payload.
The instrument, consisting of a solar tracker providing direct sunlight for two grating spectrometers, is designed for deployment on a high altitude balloon to measure total bromine and iodine inventories using solar occultation and the DOAS method. All components of the setup have been chosen to withstand low temperatures (>-80°C) and low pressures (>5 mbar) as expected during the flight, and to have minimal power consumption while being compact, lightweight and only cooling radiatively. To perform solar occultation measurements, the device can track the sun down to 10° below its horizon.

The solar tracker is based on a two-camera setup following the Camtracker [1]. One camera with a fish-eye lens (FoV 185°) that observes the sky gives the sun´s coarse position. The Alt-Azimuth mount projects direct sunlight onto a screen. When reaching this coarse position, the image of the second camera is used to center the solar image on the spectrometer entrance telescopes by adjusting both mirrors within a 100 Hz control loop.
The tracker can reach a tracking precision of ≤0.05° for expected perturbations of smaller than 2° s-1. In lab experiments it was shown, that the tracker could handle even faster perturbations (larger than 3° s-1).
The sunlight is coupled into the two spectrometers via a fiber-telescope setup.

Two stabilized spectrometers (Ocean Optics QE Pro Series, resolution 0.5 nm) with a wavelength range for UV (305 to 385 nm) and vis (415 to 515 nm) are assembled within an evacuated box inside a water-ice bath. The vacuum avoids vapors condensing on the CCD an it ensures a constant refractive index within the spectrometers throughout the flight. At the same time the water-ice bath acts as a thermal buffer to stabilize the temperature of both spectrometers. Stable water-ice bath temperatures were achieved for >12 hours with deviations smaller than 0.5°C.

Preliminary testing of the setup was conducted on a three-day stationary roof-based test campaign with nearly clear-sky conditions. We plan on further investigating the instrument´s performance under field conditions and finally deploy the instrument on a stratospheric balloon flight from Kiruna in summer 2021.

[1] Gisi, M. et al.: Camtracker: a new camera controlled high precision solar tracker system for FTIR-spectrometers, Atmospheric Measurement Techniques, URL, 2011.

How to cite: Voss, K., Holzbeck, P., Kleinschek, R., Herlan, R., Grossmann, K., Pfeilsticker, K., and Butz, A.: A compact solar occultation instrument for the UV/Visible spectral range: instrument design and performance testing, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1516,, 2021.

Vanda Grubišić, Kyu Kim, and Wen-Chau Lee

A novel, airborne phased array radar (APAR) is currently under design at the NCAR Earth Observing Laboratory. This novel airborne radar is to be carried by the NSF/NCAR C-130 aircraft. The APAR system will consist of four removable C-band active electronically scanned arrays (AESA), strategically placed on the fuselage of the aircraft. Conceptually, the radar system is divided into the front-end, the backend, and the aircraft-specific section. The front-end primarily consists of AESAs, the backend of the signal processor, and the aircraft specific section includes a power system and a GPS antenna.

APAR, with dual-Doppler and dual polarization capabilities at a lesser attenuating C-band wavelength, is designed to enable further advancement in understanding of in-cloud microphysical and dynamical processes within a variety of precipitation systems. Such unprecedented observations, in conjunction with the advanced radar data assimilation systems, is anticipated to significantly improve understanding and predictability of hazardous weather events.

At present, and with funding from both the National Science Foundation and the National Oceanic and Atmospheric Administration, NCAR is engaged in the risk reduction and APAR preliminary design activities. In this talk, we will provide an update on the status of these activities for various system components as well as the system-level design. For the final design and development of APAR, NCAR plans to apply for the NSF Mid-scale Research Infrastructure funds in 2021. It is anticipated that the APAR final design and development will be a five-year effort.

How to cite: Grubišić, V., Kim, K., and Lee, W.-C.: APAR: The Next Generation of Airborne Polarimetric Doppler Weather Radar, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13696,, 2021.

Natividad Ramos, Rémy Gallois, and Jean-Marc Gaubert

The digitalization of airborne scientific operations has become a must to secure and optimise efforts engaged on field campaigns. Thanks to affordable communication and information technologies, the potential of these special operations can be maximized.

ATMOSPHERE has developed PLANET, a network-centric operations platform that answers the specific needs of research missions. It enables efficient coordination through real-time sharing of information between mission’s stakeholders. It is now used routinely in atmospheric and Earth observation missions, such as the measurement of traces of gases and aerosols performed by the DLR Dassault Falcon D-CMET. PLANET has recently played a major role in challenging international campaigns involving aircraft, vessels, and drones (ATOMIC/EUREC4A, MOSAiC).

Under the ESA ARTES programme, ATMOSPHERE is now leveraging the solution to provide enhanced services relying on the Iridium Next satellite constellation.

This paper reviews measurement campaigns in which the use of satellite connectivity was essential, and describes how the exploitation of new ATMOSPHERE´s applications can benefit the scientific community.

How to cite: Ramos, N., Gallois, R., and Gaubert, J.-M.: Exploiting new satellite connectivity means to conduct efficient measurement missions, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-806,, 2021.

Chairpersons: Felix Friedl-Vallon, Shridhar Jawak, Sven Fahrner
Airborne Campaigns
Dirk Schüttemeyer, Tania Casal, Malcom Davidson, Matthias Drusch, Julia Kubanek, Hilke Oetjen, and Marin Tudoroiu

In the framework of its Earth Observation Programmes the European Space Agency (ESA) carries out ground based and airborne campaigns to support geophysical algorithm developments, calibration/validation activities, simulation of future space-borne earth observation missions, as well as application developments related to remote sensing of the atmosphere, land, oceans, solid earth and cryosphere.

ESA has conducted over 150 airborne and ground based measurement campaigns in the last 37 years, of which more than 80 were carried out since 2005. During this period a large number of campaigns have supported the validation of ESA’s satellite missions including for example SMOS and CryoSat. Ongoing activities are focusing on e.g. Sentinel-5Precursor and the preparation of upcoming Earth Explorer missions such as BIOMASS, FLEX, and FORUM. These validation campaigns aim to provide fundamental information about the confidence of data products and their required uncertainties One challenge in this context is a comprehensive understanding and characterization of measurement uncertainty of the validation dataset and the spatial and temporal support or representativity of these.

We will provide an overview of applied strategies to tackle these aspects for existing satellite missions and outline concepts for future missions, and how these integrate into broader earth observation science strategies. In addition, we will highlight recent activities and outline planned activities for the coming years.


How to cite: Schüttemeyer, D., Casal, T., Davidson, M., Drusch, M., Kubanek, J., Oetjen, H., and Tudoroiu, M.: ESA’s Campaign Activities in Support of Earth Observation Projects: A focus on validation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16374,, 2021.

Stefanie Holzwarth, Martin Bachmann, Bringfried Pflug, Aimé Meygret, Caroline Bès, Céline Tison, Clémence Pierangelo, Patrice Henry, Frederik Tack, Michael van Roozendael, Bernardo Motta, Martin Ligi, Riho Vendt, and Sébastien Clerc

The objective of the H2020 project “Copernicus Cal/Val Solution (CCVS)” is to define a holistic Cal/Val strategy for all ongoing and upcoming Copernicus Sentinel missions. This includes an improved calibration of currently operational or planned Copernicus Sentinel sensors and the validation of Copernicus core products generated by the payload ground segments. CCVS will identify gaps and propose long-term solutions to address currently existing constraints in the Cal/Val domain and exploit existing synergies between the missions. An overview of existing calibration and validation sources and means is needed before starting the gap analysis. In this context, this survey is concerned with measurement capabilities for aerial campaigns.

Since decades airborne observations are an essential contribution to support Earth-System model development and space-based observing programs, both in the domains of Earth Observation (radar and optical) as well as for atmospheric research. The collection of airborne reference data can be directly related to satellite observations, since they are collected in ideal validation conditions using well calibrated reference sensors. Many of these sensors are also used to validate and characterize postlaunch instrument performance. The variety of available aircraft equipped with different instrumentations ranges from motorized gliders to jets acquiring data from different heights to the upper troposphere. In addition, balloons are also used as platforms, either small weather balloons with light payload (around 3 kg), or open stratospheric balloons with big payload (more than a ton). For some time now, UAVs/drones are also used in order to acquire data for Cal/Val purposes. They offer a higher flexibility compared to airplanes, plus covering a bigger area compared to in-situ measurements on ground. On the other hand, they also have limitations when it comes to the weight of instrumentation and maximum altitude level above ground. This reflects the wide range of possible aerial measurements supporting the Cal/Val activities.

The survey will identify the different airborne campaigns. The report will include the description of campaigns, their spatial distribution and extent, ownership and funding, data policy and availability and measurement frequency. Also, a list of common instrumentation, metrological traceability, availability of uncertainty evaluation and quality management will be discussed. The report additionally deals with future possibilities e.g., planned developments and emerging technologies in instrumentation for airborne and balloon based campaigns.

This presentation gives an overview of the preliminary survey results and puts them in context with the Cal/Val requirements of the different Copernicus Sentinel missions.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 101004242.

How to cite: Holzwarth, S., Bachmann, M., Pflug, B., Meygret, A., Bès, C., Tison, C., Pierangelo, C., Henry, P., Tack, F., van Roozendael, M., Motta, B., Ligi, M., Vendt, R., and Clerc, S.: Aerial Campaigns for Cal/Val purposes in the Context of Copernicus - Survey Results of the Project “Copernicus Cal/Val Solution (CCVS)”, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12091,, 2021.

Frederik Tack, Mahesh Sha, Alexis Merlaud, Anca Nemuc, Dirk Schuettemeyer, Claus Zehner, and Michel Van Roozendael

Sentinel-5 precursor (S-5p), launched on 13 October 2017, is the first mission of the Copernicus Programme dedicated to the monitoring of air quality, climate, ozone and UV radiation. The S-5p characteristics, such as the fine spatial resolution, introduce many new opportunities and challenges, requiring to carefully assess the quality and validity of the generated data products by comparison with independent measurements and analyses.

While routine validation is performed within the ESA Mission Performance Center (MPC) based on a limited number of Fiducial Reference Measurements (FRM), additional validation activities including aerial and ground-based campaigns are conducted in research mode as part of the S-5p Validation Team (S5PVT). The validation activities bring together various teams and instruments to address specific validation requirements and provide a more in-depth, complete insight into the S-5p instrument performance and the fitness for purpose of its data products. The acquired reference data sets allow to address product accuracy and precision, spatial and temporal validation requirements, algorithm parameters (a priori profiles, albedo, etc.) and specific requirements, such as validation of strongly polluted and heterogeneous scenes.

Here, we present a series of decentralized activities planned to take place in 2021-2022 (, which have been identified to address key priorities for S5-p validation.

A first set of activities concentrates on the main S-5p UV-Vis tropospheric products (NO2, HCHO and SO2). Airborne deployment, consisting of both in-situ spiral and remote sensing mapping flights, is planned over cities and industrial areas in Romania (Bucharest; Jiu valley), the German Ruhr area (Cologne; Duisburg; Dusseldorf), Berlin, and Belgium (Antwerp (port); Brussels). Airborne operations will be complemented with various deployments on the ground (MAX-DOAS, car-DOAS, sun-photometer, ceilometer, lidar, etc.). The validation activities over Berlin and Bucharest are focused on recurrent airborne observations with hyperspectral imagers in order to have a large number of flights (12 to 18) over a time interval of approximately one year, in order to have a large statistical data set covering variable meteorological and geo-physical conditions, as well as different overpass configurations.

A second set of activities will focus on the validation of SWIR data products (CO and CH4). COCCON (COllaborative Carbon Column Observing Network) portable low-resolution EM27/SUN FTIR spectrometers will be deployed for an extended period at different sites in the world in order to obtain a good coverage of geophysical parameters (strong sources, background sites, sites with high humidity, etc.) and different ground scenes, e.g. very high/low albedo sites.

Additionally, synergies are created with large field campaigns, such as the Asian Summer Monsoon Chemical and Climate Impact Project (ACCLIP) and the 2021 NET-Sense HyTES Joint European Campaign which will provide airborne measurements of NO2, CO, CH4 columns and vertical profiles, among others.

The various airborne and ground-based instrument deployments will produce a key ensemble of independent reference observations. For each product, a core team will coordinate the validation tasks, making use of data collected in all relevant instrumental deployments.

How to cite: Tack, F., Sha, M., Merlaud, A., Nemuc, A., Schuettemeyer, D., Zehner, C., and Van Roozendael, M.: Sentinel-5p Validation Campaigns – Planned Activities in 2021-2022, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8889,, 2021.

Dragoș Ene, Jeni Vasilescu, Mihai Boldeanu, Andreea Calcan, Magdalena Ardelean, Daniel Constantin, Alexis Merlaud, and Dirk Schüttemeyer

Validation campaign for satellite missions requires efforts in terms of planning, logistics and depends on the weather for its execution. Furthermore, passive instrumentation is more sensitive at the weather, since requires special atmospheric conditions (e.g., cloud-free sky) for optimum performance. In this paper are presented activities regarding the preparation of Sentinel 5P validation in Romania, activities funded by ESA that involve ground-based (fixed and mobile – by DOAS sensors), and airborne measurements.

Research aircraft is based on a Britten-Norman BN-2 Islander platform, custom modified to accommodate, within the cabin, instrumentation for in situ measurements of aerosols (e.g., an Aerosol Particle Sizer and a nephelometer), trace gases (e.g., Picarro, and NO2 CAPS), and NO2, SO2 and H2CO column measurements (e.g., custom made DOAS whiskbroom imager for high-resolution mapping). The aircraft modification, already certified by EASA, include also the installation of an air inlet for the in-situ measurements, a nadir window for the remote sensing, and a GPS antenna for the IMU.

Measurements are planned to start in the spring of 2021 and to last until the end of the year. Region of interest is Bucharest metropolitan area, a city affected by infringement from the EU regarding poor air quality. The strategy is to perform seasonal measurements for mapping the variability of all pollution sources, e.g.: higher production from the local power plants (providers for hot water and heating for the residential population) in winter, car traffic concentrated towards the north, east or west (depending by the season).

This variability is observed also from the TROPOMI measurements, more precisely in the NO2 column concentration. During the spring and summer, the maximum is concentrated within the city centre, while for the autumn and winter, the area is more extended. Maximum values are recorded during the winter, as are shown from the 2019 and 2020 data. Moreover, the amount of S5P measurements during the winter is fewer compared with the summer, due to the presence of clouds, thus planning and execution of a campaign during wintertime being more challenging.

How to cite: Ene, D., Vasilescu, J., Boldeanu, M., Calcan, A., Ardelean, M., Constantin, D., Merlaud, A., and Schüttemeyer, D.: An integrated approach for the validation of Sentinel-5P with annual observation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11151,, 2021.

Lieven Clarisse, Frederik Tack, Thomas Ruhtz, Alexis Merlaud, Lara Noppen, Martin Van Damme, Dirk Schuettemeyer, Pierre Coheur, and Michel Van Roozendael

Anthropogenic atmospheric emissions of the reactive nitrogen components nitrogen dioxide (NO2) and ammonia (NH3) have majorly altered the global nitrogen cycle in the past 100 years, with devastating consequences to biodiversity, soil, water and air quality. Thanks to effective legislation, NO2 emissions are declining worldwide. Unfortunately, this is not the case for NH3 for which a recent study reports yearly increases of around 2% in Europe and the U.S. and up to 6% in East Asia. 

Both species are currently actively monitored with several satellite sounders, which provide daily global measurements. Yet, the spatial resolution of current sounders is inadequate for resolving the highly heterogonous spatial distributions of both species. This is particularly the case for point source emitters, for which satellites are currently only able to quantify the largest and most isolated ones. To fill the important gap in the monitoring landscape, a satellite called Nitrosat has been proposed in answer to ESA’s Earth Explorer call.  The satellite would allow making simultaneous measurements of NO2 and NH3 at a spatial resolution of 500 meter. In support to the Nitrosat proposal, ESA has funded a project called NITRO-CAM (Nitrogen cycle airborne measurements), which aims at mapping simultaneously NO2 and NH3 in the Greater Berlin area using aircraft measurements. It is the results of this campaign that are presented here. These can be seen as proof-of-concept for Nitrosat, but are also interesting in their own right. A larger focus is given to NH3, for which the presented measurements are the first of their kind.

Campaign flights were performed in the surroundings of Berlin in the autumn of 2020. A follow-up campaign is foreseen in early spring. Measurements are performed with BIRA’s UV-VIS spectrometer newly-developed SWING instrument for NO2 and TELOPS thermal infrared HYPER-CAM for NH3. Surveying gapless areas of at least 10 by 10 km, the measurements enable capturing the emissions of both point and area sources, and are suitable for degrading at various hypothetical satellite instrument footprints.  For NO2 specifically, Berlin and nearby power plants are targeted, while for NH3 the Piesteritz fertilizer factory is targeted, as well as rural areas in the surroundings of Berlin.   

How to cite: Clarisse, L., Tack, F., Ruhtz, T., Merlaud, A., Noppen, L., Van Damme, M., Schuettemeyer, D., Coheur, P., and Van Roozendael, M.: Aircraft observations of NO2 and NH3 over selected locations in Germany, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12645,, 2021.

Daniel Spengler, Max Gulde, Bierdel Marius, Welling Cassi, Stottmeister Alex, Atin Jain, and Ruhtz Thomas

PASTRI will be a joint pilot study of ConstellR, GFZ Potsdam and FU Berlin for airborne based aerial surface temperature retrieval. The mission is planned as a preparation and demonstrator mission for the upcoming spaceborne thermal satellite microsatellites of ConstellR. ConstellR will provide a land surface temperature (LST) monitoring service with an initial focus on companies in the precision farming industry. The initial minimal viable constellation (MVC) of four microsatellites will offer global, daily LST monitoring at 50 m spatial resolution with 1.5 K radiometric accuracy for a monitoring area capacity comparable to the size of Germany’s agricultural area.

The authors intend to use a six-week airborne campaign in May/June 2021 as a data delivery pilot to develop and validate the provision of an LST product. In total 18 flights are planned (3 flights/week every second week, 2 flights/day) with the FU Berlin Cessna T207A. On the technical side, the project includes the payload development and adaptation to the mechanical interface of the airplane, the actual (airborne) recording or imagery, as well as setting up the data processing pipeline. The aircraft will be instrumented with an adapted ConstellR Sensor and a thermal hyperspectral Telops HyperCam. This enables a performance evaluation of the microsatellite sensor performance against a hyperspectral reference instrument. Based on that results, final adaptions could be made for the spaceborne sensors. The flights will be performed in Central Germany at agricultural sites and will be supplemented by in-situ reference measurements.

The concept and the status of preparation of the campaign will be presented.

How to cite: Spengler, D., Gulde, M., Marius, B., Cassi, W., Alex, S., Jain, A., and Thomas, R.: PASTRI - Pilot for Aerial Surface Temperature Retrieval, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1289,, 2021.

Paul Barrett, Steven Abel, Humphrey Lean, Jeremy Price, Thorwald Stein, Alison Stirling, and Timothy Darlington

Faithfull physical representation of summertime convection over the United Kingdom, and beyond, remains elusive in convection permitting (CP) numerical weather prediction (NWP) models.  Biases include the incorrect representation of the size and spatial distribution characteristics of convective elements, timing errors in the diurnal cycle of convection and under-representation of high-intensity precipitation events. A key requirement for model improvement is 3D observations of convective clouds, updrafts and turbulence along with the pre-convective environment.

Increased computational power and novel parameterisation schemes (e.g. CoMORPH: scale-aware convection scheme, CASIM: Cloud AeroSols Interactive Microphysics) are on the cusp of facilitating significant advances to the representation of convective cloud systems, both at high resolution cloud resolving scales from O(100m) to O(1km) and for CP ensemble prediction systems. Observational constraints are now required to validate and develop this suite of numerical modelling and the WesCon campaign has been designed for this purpose.

Met Office and University of Reading are planning an observational field campaign from June through to August 2023 to investigate summertime convection. Focussing on the Wessex region encompassing South West and South Central England we will benefit from the remote sensing capability of  the Chilbolton Observatory to observe clouds and precipitation (including a new X-band radar) and the research radar (C-band) at Met Office Wardon Hill (Dorset) to observe precipitation structures.

Up to 80 research flight hours with the FAAM BAe146 research aircraft (Facility for Airborne Atmospheric Measurement) will probe the thermal, dynamical, updraughts and microphysical structures of the planetary boundary layer and lower free-troposphere on horizontal length-scales from the turbulence scale O(1 m) to the mesoscale (10’s kms). Ground based measurements will be deployed across the region making observations of surface exchange, turbulence and boundary layer properties. Radiosondes and dropsondes along with aircraft profiles will probe the atmosphere in the vertical.

Airborne measurements will place particular emphasis on the pre-convective environment, convective inhibition (CIN) and the early stages of the development of convective systems.  The full lifecycle of convective systems will be observed from the vantage point of remote sensing observations.

Here we present the aims and measurement strategy of the WesCon campaign and solicit interest and involvement from other modelling or observations groups within the community who may wish to join us to collaborate.

How to cite: Barrett, P., Abel, S., Lean, H., Price, J., Stein, T., Stirling, A., and Darlington, T.: WesCon 2023: Wessex UK Summertime Convection Field Campaign, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2357,, 2021.

Niklas Neckel, Niels Fuchs, Angelika Humbert, Veit Helm, Gerit Birnbaum, Lars Kaleschke, and Christian Haas

In summer, melt ponds on arctic sea ice can cover up to 60% of the total sea ice area, significantly decreasing surface albedo. The latter also holds true for supraglacial lakes frequently forming in the ablation zone of the Greenland Ice Sheet. Therefore monitoring of both, melt ponds on sea ice and supraglacial lakes is of great importance. So far, detection algorithms for both phenomena have been developed seperately from each other. Here, we will use airborne optical data of supraglacial lakes acquired during a land ice campaign over north-east Greenland in 2013 and airborne images of melt ponds from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) campaign to illustrate similarities and differences in the appearance of both phenomena. As an example study, we use an open source processing chain including the Open Drone Map software as well as the AMES stereo pipeline to generate orthorectified photo mosaics. On the basis of these datasets, we will discuss typical detection methods as well as the difficulties they face in the respective environment (f.e. confusion with shadows and bare ice). Besides a modified normalized difference water index we test an adapted random forest approach that was developed for the analysis of MOSAiC melt pond data and conclude with suggestions for future algorithm development.

How to cite: Neckel, N., Fuchs, N., Humbert, A., Helm, V., Birnbaum, G., Kaleschke, L., and Haas, C.: Observations of Arctic melt ponds and supragacial lakes from airborne camera data, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10673,, 2021.

Jennifer Sobiech-Wolf, Tobias Ullmann, and Wolfgang Dierking

Satellite remote sensing as well as in-situ measurements are common tools to monitor the state of Arctic environments. However, remote sensing products often lack sufficient temporal and/or spatial resolution, and in-situ measurements can only describe the environmental conditions on a very limited spatial scale. Therefore, we conducted an air-borne campaign to connect the detailed in-situ data with poor spatial coverage to coarse satellite images. The SMART campaign is part of the ongoing project „Characterization of Polar Permafrost Landscapes by Means of Multi-Temporal and Multi-Scale Remote Sensing, and In-Situ Measurements“, funded by the German Research Foundation (DFG).  The focus of the project is to close the gap between in-situ measurements and space-borne images in polar permafrost landscapes. The airborne campaign SMART was conducted in late summer 2018 in north-west Canada, focussing on the Mackenzie-Delta region, which is underlain by permafrost and rarely inhabited. The land cover is either dominated by open Tundra landscapes or by boreal forests. The Polar-5 research-aircraft from the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Germany, was equipped with a ground penetrating radar, a hyperspectral camara, a laserscanner, and an infrared temperature sensor amongst others. In parallel to the airborne acquisition, a team collected in-situ data on ground, including manual active layer depth measurements, geophysical surveying using 2D Electric Resistivity Tomography (ERT), GPR, and mapping of additional land cover properties. The database was completed by a variety of satellite data from different platforms, e.g. MODIS, Landsat, TerraSAR-X and Sentinel-1.  As part of the project, we analysed the performance of MODIS Land surfaces temperature products compared to our air-borne infrared measurements and evaluated, how long the land surface temperatures of this Arctic environment can be considered as stable. It turned out that the MODIS data differ up to 2°C from the air-borne measurements. If this is due to the spatial difference of the measurements or a result of data processing of the MODIS LST products is part of ongoing analysis.

How to cite: Sobiech-Wolf, J., Ullmann, T., and Dierking, W.: SMART – Space monitoring of Arctic Tundra landscapes, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14864,, 2021.

Jevgenijs Filipovs, Amanda Berg, Jörgen Ahlberg, Alekss Vecvanags, Agris Brauns, and Dainis Jakovels

The surveillance of wild animal populations is important for wildlife sustainability, conservation and management. It has been estimated that the UAV-based survey of 100 ha large territory is ~10 times less time-consuming in comparison to surveys based on traditional field visits. Aerial surveys using thermal and visible light cameras allow remote observation of wildlife over relatively large geographical areas where the thermal imager is often used as a primary sensor for the detection of animal shape similar hot-spot, but higher-resolution visible light imaging data is used for the reduction of false-positive detections. Recent developments in unmanned aerial vehicles (UAVs), artificial intelligence and miniaturized dual imaging systems made it more flexible, affordable and accurate for aerial surveillance of wild animals. This study was conducted as part of project “ICT-based wild animal census approach for sustainable wildlife management” co-financed by the ERDF program “Industry-Driven Research” (dnr and managed by the Institute for Environmental Solutions, Latvia. One part of the project activity is to develop the detection and classification workflow of wild animals from areal imaging data. This study describing data acquisition, detection and automated data pre-processing of thermal and RGB image co-registration as input for the development of animal classification algorithm. The focus of the study was a detection of the four dominant even-toed ungulate species in Latvia - elk (Alces alces), red deer (Cervus elaphus), roe deer (Capreolus capreolus) and wild boar (Sus scrofa). The data acquisition was performed over the fenced deer garden and open forest pilot territory located in Ramuļi, Latvia. The chosen UAV system was a quadrocopter platform with a dual-camera on the board. Initially, the main focus in data acquisition was over-fenced deer garden at different day times, weather conditions to collect data with animal presence as well as test different data acquisition regimes, strategies and animal behavioral response. Three flights with total coverage were performed over the deer garden area. After the post-detection of individuals, the average estimated accuracy was 88% of the known reference number of deers. Further on, drone flights were conducted over the whole pilot territory to obtain data of other species and behavioral overview in open forest land conditions. All collected data were registered in the database to annotate the weather conditions and the presence of an animal in a certain minute. In total 10 flights (3 h) were performed over the deer garden and 93 (45 h) flights over the open forest land pilot territory. The capabilities of the drone-based monitoring system with a dual-camera imaging setup will be presented.

Keywords: UAV, elk, deer, roe deer, areal imagery, dual-camera, detection

How to cite: Filipovs, J., Berg, A., Ahlberg, J., Vecvanags, A., Brauns, A., and Jakovels, D.: UAV areal imagery-based wild animal detection for sustainable wildlife management , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14137,, 2021.

Charmaine Cruz, Kevin McGuinness, Jerome O'Connell, James Martin, Philip Perrin, and John Connolly

The EU Habitats Directive (HD) requires that natural habitats are monitored every six years to assess habitat condition, extent and range. In Ireland, reporting for the HD is based on ecological field surveys. This field-based mapping and assessment methodology, while desirable, can be time-consuming, difficult, and expensive. It also only covers a sub-sample of sites due to cost. Thus, more efficient mapping approaches, such as remote sensing, should be considered to supplement these monitoring techniques.  

Here we present some preliminary results from the iHabiMap Project. The overall aim of iHabiMap is to develop and assess analytical approaches that use machine learning techniques to derive habitat maps from imagery acquired by Unmanned Aerial Vehicle (UAV). The project started in 2019 and to date twelve UAV surveys have been conducted acquiring very high-resolution (6 cm) multispectral imagery for five selected study sites. Ecological data were collected concurrently with each UAV survey to obtain the actual state of the recorded vegetation. The project focuses on assessing imagery from three habitat types: upland blanket bog, coastal dunes, and grassland in Ireland. In this abstract we focus on the coastal dunes.

The Random Forest (RF) machine learning algorithm using the python Scikit-learn library was utilized to identify and map the habitats. The pixel-based RF model was calibrated using a combination of ground truth data and several colour, band ratios, and topographic variables derived from the UAV data. Six separate models were generated to compare how classification accuracies change based on combinations of input variables. The methodology was initially implemented to classify four sand dune Annex I habitats: 2120 - Marram dunes; 2130 - Fixed dunes; 2170 – Dunes with creeping willow; 2190 – Dune slacks, in the Maharees site in Ireland. The results were analyzed using the standard confusion matrix to calculate overall and class-specific accuracies. Preliminary results suggest that RF can classify sand dune Annex I habitats 2120, 2130, 2170, and 2190, with overall accuracies ranging from 0.80 to 0.93, depending on the input variables. The highest accuracy was achieved using the combined spectral and topographic information. Feature importance metrics calculated from RF showed that the surface elevation and Green Normalized Vegetation Index (GNDVI) were the key input variables in the classification. The results obtained from the presented workflow demonstrate the potential of using UAV, machine learning techniques, and field data in characterizing coastal dune environments. The classification will be further expanded to explore phenological differences of the vegetation by including the temporal dimension of the data and will be tested on the upland and grassland habitats. Moreover, an upscaling methodology will be implemented to assess UAV data usability on a broader scale mapping.

How to cite: Cruz, C., McGuinness, K., O'Connell, J., Martin, J., Perrin, P., and Connolly, J.: Habitat mapping in coastal dunes using Random Forest classification of UAV images, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6301,, 2021.