The Small Unmanned Observer (SUMO) has been developed by the Paparazzi community together with the Geophysical Institute of the University of Bergen, Norway. It is designed to support research in the lower atmospheric boundary layer. It uses industry standard sensors like temperature, air pressure, humidity and wind speed/direction as well as more specialized sensors as infrared/visible light radiation, particle concentration or ionizing radiation (full list). It has been used in many measurement campaigns by various research institutions.
As with all Paparazzi software and hardware this does not come with any guarantee, in particular no part of the system is certified by any national or international authority. Please refer to the national aviation regulation for Remotely Piloted Aircraft Systems of the accountable country before you start operating. A special permit is usually needed for any activity not related to hobby/recreational usage and especially important if you intend to fly at high altitudes. The experience is that the necessary consultations need quite some time and effort.
Build your own
The SUMO is bascially an RC airplane equipped with additional hardware for automatic flight and to collect data for scientific usage. It needs some knowledge in the fields of model airplanes, electronics, hard- and software to build and operate it. One successful strategy for an university research group might be to team up with the engineering department. Get in contact with local RC enthusiasts and ask them to support you in safety piloting the aircrafts. There are many different ways to assemble a Paparazzi aircraft. We are describing a way hat has shown great results in the past years.
The groundstation consists of a laptop, a bi-directional modem, a standard RC transmitter and battery chargers.
The computer should be able to operate outdoors and cope with dust, water, temperature, etc. We have mainly used Panasonic Toughbook CF-19 laptops that never showed any weakness. The recommended operating system is Ubuntu 12.04 LTS.
The modems section describes an overwhelming number of various modems that are available for all sorts of applications. The 2.4GHz Digi XBee Series 1 are proven all-purpose modems that can be used almost world wide. For the ground station we use the readily available Digi XBee USB modem in a robust metal case. It is connected to the laptop through a standard USB A-B cable and brings its own whip antenna.
The RC world gives you many options to control your aircraft. If you or any supporting team member already owns an RC system, you might try to get this to work. It is important that your RC receiver supports the output of a sum signal that contains all servo data in one signal. You need an extra channel for switching the flight mode. If you start from scratch the Futaba/robbe system is a good option.
There are many different brands and types available and we can not really give a suggestion. We were happy with devices from evoTech or Schulze. Get in contact with your local RC dealer and find a device suitable for you. It is important that the device fits to the power requirements you will see in the field (12V DC/115V AC/230V AC). Do not buy the cheapest available. Follow the instructions carefully, Lithium Polymer batteries can be dangerous.
We chose to use the Multiplex Funjet right after it appeared in 2006. The goal was to have an aircraft that can fly fast to be able to operate in wind conditions up to 15m/s. To achieve an easy take-off for non-RC-enthusiasts we equipped it with a bigger propeller than normal (9x6). Some outer parts have been strengthend with glass fiber. The recent Funjet Ultra can also be used but we do not see much improvement for our goals. It is heavier and the visibility is poor.
The Funjet is not a beginners airplane. Get some piloting help when you are new to RC. You always need a safety pilot that can take over the aircraft.
Use the best RC parts you can get. There is no use in saving some Euros on this. We use Graupner servos, an AXI motor and Jeti motor controller.
Prepare specific electronic parts
These are the non-standard parts you need. Look in the get hardware section for a source of these parts. In the current version of the SUMO we use the Umarim Lite v2 autopilot, a TWOG board as data logger, a Digi XBee Pro Series 1 modem, a Hygrosens temperature sensor, Sensirion humidity sensor, Meas Spec pressure sensor and an optional Eagletree airspeed v3 sensor.