The invention specifically provides a method for monitoring
plant growth by using an unmanned aerial vehicle with a multispectral
light source, belonging to the technical field of monitoring of
plant growth. The method comprises the following steps: determining the characteristic wavelengths of plants according to the species of the plants and selecting a corresponding standard
narrowband colored light combination as a standard multispectral
light source; irradiating the plants with the standard multispectral
light source, acquiring information like the
chromaticity coordinates and reflection spectra of the plants of different species and establishing a
plant spectrum
database; controlling the unmanned aerial vehicle to
shoot a detected plant by using an area-array CCD spectral imager and to store information; and comparing the information of the shot detected plant with information like the
chromaticity coordinates and reflection spectra of leaves of a plant of a same species in the plant spectrum
database so as to analyze the growth condition of detected leaves. According to the invention, the unmanned aerial vehicle carries the multispectral light source and the area-array CCD spectral imager for monitoring, so the coverage area of a single scanning is great and measuring precision is high; the unmanned aerial vehicle is simple in flight
route, easy to control and low in cost; thus, the method is applicable to monitoring of
plant growth during current agricultural plantation in fields, greenhouses, plant factories, etc.