The picture shows a hyperspectral camera in the grass

Sensors

We are using various remote and in-situ sensing systems at CPA. Our primary focus is on state-of-the-art spectrometers and hyperspectral cameras to obtain reflectance and fluorescence information, from which we infer a multitude of plant properties. In addition to that, we also utilize thermal cameras for plant stress detection, and we use sensors for mapping soil variation along with conventional sensors for weather data acquisition. We present an overview of selected sensors in the following.

Spectrometers

Yara N-Sensor

We utilize the Yara N-Sensor (passive) on our tractors to measure the spectral reflectance signature of the plant canopy. It is equipped with VIS-NIR spectrometers (400-900 nm) to simultaneously detect the incident down-welling radiation and the upwelling canopy reflection at a nadir angle of 60°.

Yara N-Sensor hand held

As the tractor-mounted N-Sensor, we utilize the same measurement principle with two Tec5 MMS1 spectrometer in a hand held version for small plots in experimental field trials.

ASD FieldSpec

For measuring radiation in an extended spectral range (350-2500 nm) and at higher spectral resolution (1 nm), we make use of the ASD FieldSpec 3 spectroradiometer.

Ocean Optics spectrometer

We have several Ocean Optics point spectrometers, which are sensitive to UV-VIS-NIR radiation (200-1100 nm). Our customized USB 4000 with a very high spectral resolution (0.1 nm) is used for research applications that require the detection of slight reflection differences and fluorescence emissions. Our USB 2000 and the FLAME-series spectrometers are used as field spectrometers or to detect incident radiation on the prototype hybrid UAV.

Cameras

Rikola hyperspectral camera

We use the Rikola Hyperspectral Camera for many remote sensing applications in the greenhouse, the field or on-board our UAVs. The camera is light-weight and sensible to radiation in the VIS-NIR range (450-800 nm), whereas the bands can be selected individually. In USB-mode we sample up to 200 different bands while the number of bands is reduced to a maximum of 32 in flight-mode.

Imec and Ximea hyperspectral camera

In addition to the Rikola Hyperspectral Camera, we use small and light-weight industrial hyperspectral snapshot cameras of the Imec and Ximea XiQ product line. Currently, we are working with the SSM2x2-RGB-NIR-10.2, the MQ022HG-IM-SM4X4-NIR, and the MQ022HG-IM-SM5X5-NIR cameras. The cameras provide information from 4 to 25 bands in the 400-950 nm range at a sampling rate of up to 170 frames/s.

Flir Tau thermal camera

For thermal imaging in the TIR range (7.5-13.5 μm) we use the Flir Tau Uncooled Microbolometer. The camera is mainly used as a hand held device or on-board our UAVs.

Navigation sensors

Trimble Geo7X

We use the Trimble Geo7x global navigation satellite receiver (GNSS) for high-precise real-time kinematic (RTK) measurements (1-3 cm CEP). The Trimble Geo7X can be used as a hand held device or for permanent tracking on-board our tractors and UGVs.

Swift Navigation Piksi

For high precision navigation on-board our UGVs, we use the Piksi GNSS together with our own base receiver station. For the prototype hybrid UAV, we will use the latest version Piksi Multi with multi-band support for more accurate centimeter-accuracy.