Field Experiments & Instrumentation / Workshops                    --- Making Things Happen ---     


Unmanned aircraft for research

The new UAV service at BGC



WHY UNMANNED AIRCRAFT?

The use of unmanned aircraft (also called unmanned aerial vehicles, UAVs) in Earth Science has increased tremendously in recent years. They allow vertical profiling of the atmosphere, the acquisition of measurements over large areas in little time and provide views from above. A great variety of platforms with different strengths and weaknesses is being used, such as aeroplanes, gliders, multicopters, helicopters and more. Importantly, their costs of acquisition and operation are relatively low, giving researchers for instance the possibility to collect high-resolution aerial imagery at a fraction of the cost of manned aerial photography. Modifications are simple and most platforms can be used for diverse missions. Since November 2017 a new central service is being established at the Max-Planck-Institute for Biogeochemistry to harness the power of UAVs for our research. This central service will manage different platforms and measurement devices and support researchers in planning, execution and analysis of UAV-based measurements.


ADVANTAGES OF A CENTRAL SERVICE

...compared to per-group solutions

  • Scientists need to worry less about technical issues and can focus on the results
  • Concentration of UAV expertise
  • Reuse of analysis workflows
  • Refinement of data analysis methods over time
  • Reuse of existiig measurement systems and UAV platforms




UAV TYPES

Multicopters

+ Vertical take-off and landing capability
+ Ability to hover in place
- Endurance typically limited to 15-30 min
- Reach limited by maximum speed of typically < 10m/s
- Strong rotor downwash influences in situ measurements

Fixed-wing aircraft

+ High speeds > 20 m/s possible
+ Endurance typically 15-60 min
+ Less disturbance of the air underneath the aircraft
- Cannot fly very slow
- Require landing strip or large net
- Larger platforms require catapult or paved runway for take-off

Other platforms

Helicopters: high lift, more efficient than multicopters
Quadplanes / Tilt-rotors: Combine performance of fixed-wing aircraft with vertical take-off and landing capabilities


SENSORS AND MEASUREMENTS

In situ

Temperature, humidity and pressure sensors

⦁ Meteorology
⦁ Quantification of dewfall

Trace gas analysers (CO2, CH4, ...)

⦁ Emission mapping
⦁ Flux estimation by budget or mass-balance approach

Spatially resolved sampling with AirCore

⦁ Isotopic composition
⦁ Very-low concentration tracers

Proximal sensing

Cameras for optical and multispectral (VIS + NIR) imaging

⦁ Species classification
⦁ Plant health / senescence
⦁ Photogrammetry / Structure from motion

Spectrometers (VIS, NIR, SWIR)

⦁ Plant health / senescence
⦁ Potentially solar-induced chlorophyll fluorescence

Thermographic cameras

⦁ Surface energy balance ⦁ Proxy for soil moisture