A multinational team of researchers from Germany, Italy, Spain and New Zealand developed the UAV-based system and conducted the initial experiments, gathering high-resolution reflectance spectra from the UAV at altitudes of up to 200 meters and irradiance spectra from the ground-based spectrometer. According to team leader Andreas Burkart of the Research Center Jülich IBG-2 Plant Sciences, Germany, collection of hyperspectral data by field spectroscopy is a time-consuming task and often is restricted to easily accessible areas.
The small size and weight of the STS spectrometer is ideal for use on the UAV, which allows a series of fast and reproducible measurements over any terrain, even forest or marsh. By measuring various segments across a section of the New Zealand pastureland, the system was able to assess information such as specific plots that contained live vegetation.
The STS is a remarkably small CMOS detector-based spectrometer that is less than 2 inches square (40 mm x 42 mm) and weighs a little over 2 ounces (68 g). It performs comparably to larger systems, providing full spectral analysis with low stray light, high signal to noise (>1500:1) and excellent optical resolution. For the application described here, the researchers were able to match the performance of the STS to that of a larger, more expensive commercially available field portable spectrometer, with optical resolution of ~2.5 nm (FWHM).
