According to estimates provided by experts, the most important apple types in Germany suffer losses of around 13% on their from harvest to consumer. In addition to the lack of these food products, this results in a high loss of natural resources and inefficient use of labour. Other key factors in terms of costs and environmental impact are high energy consumption with high CO2 emissions and loss of quality during fruit storage.
As part of the research project BigApple, hyperspectral measurements were carried out on test trees at the KOB orchard (Kompetenzzentrum Obstbau-Bodensee) in Bavendorf near Lake Constance, Southern Germany. The focus of the measurements was on two classes, i.e. apple and leaf. The spectral measurement data is the basis for the determination of physiological growth/fruit parameters, which are considered in the form of indices in the modelling and analysis of our project partners and are intended to contribute to improved apple storage.
The hyperspectral measurement was performed in the laboratory under controlled measuring conditions. Furthermore, measurement campaigns were carried out in the orchard of the KOB. The hyperspectral camera S185 with the wavelength range 450 – 950 nm was used for these purposes.
By this, the desired objects could be measured throughout the quasi-continuous spectrum using 125 channels with a bandwidth of 4 nm. Figure 1 shows an example of a measurement setup with the hyperspectral camera S185 and the mobile data processing system at the orchard. The acquisition, processing and storage of the data took place with the in-house software Cubert Utils during the measurement.