SUMO: A Small Unmanned Meteorological Observer for atmospheric boundary layer research

The measurement system SUMO (Small Unmanned Meteorological Observer) for the determination of temperature, humidity and wind profiles in the atmospheric boundary layer has been developed on the basis of a small and light-weighted model aircraft. The system in its current version is based on the electric powered FunJet model airplane by Multiplex, equipped with the Paparazzi autopilot system and meteorological sensors for temperature, pressure and humidity. Wind profiles can be calculated by combining the speed of the aircraft above ground from GPS measurements with flight attitude information as throttle, pitch and roll, continuously monitored by the autopilot. With its length and wingspan of 80 cm and an overall weight of around 600 g it is easily transportable and therefore ideal for application in remote areas. The lithium polymer battery provides energy for about 25 minutes of flight.

A prototype of SUMO has successfully passed its first environmental application during the international mesoscale meteorological field campaign FLOHOF on and around Hofsjøkull in Central Iceland in July/August 2007. During the campaign more than 50 profile flights could be performed, reaching a maximum altitude of 3.5 km above ground. During February and March 2008 the SUMO system will also be operated during the IPY THORPEX campaign in polar environment on and around Spitzbergen.

A short technical description of the system will be given, including a short discussion of algorithms used to correct temperature and humidity profiles for the sensor time lag during rather fast ascend and descend rates up to of 10 m/s. Finally profiles of temperature, humidity and wind measured during FLOHOF and THORPEX will be presented together with a comparison to tethered balloon, radiosonde, and pilot balloon measurements.