COCAP: a carbon dioxide analyser for small unmanned aircraft systems
Martin Kunz1,Jost V. Lavric1,Christoph Gerbig1,Pieter Tans2,Don Neff2,Christine Hummelgård3,Hans Martin3,Henrik Rödjegård3,Burkhard Wrenger4,and Martin Heimann1,5Martin Kunz et al. Martin Kunz1,Jost V. Lavric1,Christoph Gerbig1,Pieter Tans2,Don Neff2,Christine Hummelgård3,Hans Martin3,Henrik Rödjegård3,Burkhard Wrenger4,and Martin Heimann1,5
1Max Planck Institute for Biogeochemistry, Jena, Germany
2NOAA Earth System Research Laboratory, Global Monitoring Division,
Boulder, Colorado, USA
3SenseAir AB, Delsbo, Sweden
4Ostwestfalen-Lippe University of Applied Sciences, Höxter, Germany
5Division of Atmospheric Sciences, Department of Physics, University
of Helsinki, Helsinki, Finland
1Max Planck Institute for Biogeochemistry, Jena, Germany
2NOAA Earth System Research Laboratory, Global Monitoring Division,
Boulder, Colorado, USA
3SenseAir AB, Delsbo, Sweden
4Ostwestfalen-Lippe University of Applied Sciences, Höxter, Germany
5Division of Atmospheric Sciences, Department of Physics, University
of Helsinki, Helsinki, Finland
Correspondence: Martin Kunz (mkunz@bgc-jena.mpg.de)
Received: 21 Jun 2017 – Discussion started: 07 Nov 2017 – Revised: 30 Jan 2018 – Accepted: 22 Feb 2018 – Published: 29 Mar 2018
Abstract. Unmanned aircraft systems (UASs) could provide a cost-effective way to close gaps in the observation of the carbon cycle, provided that small yet accurate analysers are available. We have developed a COmpact Carbon dioxide analyser for Airborne Platforms (COCAP). The accuracy of COCAP's carbon dioxide (CO2) measurements is ensured by calibration in an environmental chamber, regular calibration in the field and by chemical drying of sampled air. In addition, the package contains a lightweight thermal stabilisation system that reduces the influence of ambient temperature changes on the CO2 sensor by 2 orders of magnitude. During validation of COCAP's CO2 measurements in simulated and real flights we found a measurement error of 1.2 µmol mol−1 or better with no indication of bias. COCAP is a self-contained package that has proven well suited for the operation on board small UASs. Besides carbon dioxide dry air mole fraction it also measures air temperature, humidity and pressure. We describe the measurement system and our calibration strategy in detail to support others in tapping the potential of UASs for atmospheric trace gas measurements.
Unmanned aircraft could provide a cost-effective way to close gaps in the observation of the carbon cycle, provided that small yet accurate analysers are available. We have developed a COmpact Carbon dioxide analyser for Airborne Platforms (COCAP). During validation of its CO2 measurements in simulated and real flights we found a measurement error of 1.2 μmol mol−1 or better with no indication of bias. COCAP is a self-contained package that has proven well suited for operation on board UASs.
Unmanned aircraft could provide a cost-effective way to close gaps in the observation of the...
