As a result of hyperspectral measurements carried out on the test plots of the All-Russian Research Institute of Biological Plant Protection, we obtained the reflection spectra of individual cultivated and weed species. Along with the ground-based measurements, trials of the GEOSCAN drone equipped with a Gamaya hyperspectral camera were organized. We developed a database of spectral characteristics of weeds. The change in the shape of the spectral signatures of the reflectivity of plant objects depending on their actual condition, taken into account during field surveys, was analyzed. An analysis of the spectral curves showed that the results of field spectrometry are in good agreement with aerial survey data.