Vegetation monitoring in Groningen

Potential applications for drone technology  are abundant  in the agricultural sector. T&A Drone Services' expertise on spectral remote sensing allows us to add significant value to the use of drones.  

Fungi detection
Currently entire fields are preventatively sprayed with fungicide on a regular basis. Early detection of incipient fungus infection in wheat is important as it can significantly reduce the use of fungicide. If detected early, farmers can treat fungi locally.  

Infrared spectrometry
 
Using a portable IR spectrometer, we have taken spectral measurements of wheat leaves with different levels of Fungus infestation, ranging from healthy to strongly affected. The spectra (plot with spectra) indicate that there are systematic spectral changes with increasing deterioration of the plants’ health. A very good indicator seems to be the “red-edge” position (plot with pointdata).  

Aibotix multirotor
The most efficient way to make a rapid assessment of the condition of a wheat field is the use of drones to collect spectra through hyperspectral imagery. To prove this, a test flight was done using the Aibotix multirotor with a normal RGB camera. The great advantage of the multirotor is that it can fly slowly and low enough to create an image with a resolutions so high that it is possible to map individual leaves. This is important, as our study has shown that the leaves of one single plant can have different spectral properties. Flying at higher speed and elevation will decrease the spatial resolution, mixing spectra from different materials (also soil). As a result the sensitivity of the measurement will drop significantly.

Top right: Aibotix in action
Bottom left: Image showing the vegetation greenness
Bottom right: Spectral characteristics (Red edge position) of wheat leaves at different levels of fungus infestation.