In this study, a 400-1000nm hyperspectral camera can be used, and the products of Hangzhou Color Spectrum Technology Co., LTD
FS13 conducts related research. The spectral range is 400-1000nm, and the wavelength resolution is better than 2.5nm, up to 1200
Two spectral channels. Acquisition speed up to 128FPS in the full spectrum, up to 3300Hz after band selection (multi-zone support
Domain band selection).
Chlorophyll plays an important role in plant photosynthesis, and its content is an important indicator of plant nutrient stress, photosynthetic capacity and growth status. The detection of plant chlorophyll content can be used to monitor plant growth and development, so as to scientifically guide cultivation and fertilization management, ensure good crop growth, improve crop quality and yield, which is of great significance for the practice of precision agriculture and forestry. The traditional chlorophyll content detection method is analytical chemistry method, that is, the leaves are collected in the laboratory, extracted by chemical solvent, and then the absorbance of the extracted liquid at two specific wavelengths is determined on the spectrophotometer, and the chlorophyll content is calculated according to the formula. This method has high measurement accuracy, but it is cumbersome, time-consuming and laborious, and it can not meet the requirements of rapid non-destructive testing in the field.
Visible near-infrared spectroscopy is a rapidly developed method of analysis and detection in recent years, which can make full use of spectral data at full spectrum or multi-wavelength for qualitative or quantitative analysis. Compared with the traditional analytical chemistry method, visible near-infrared spectroscopy has the characteristics of fast analysis, high efficiency, low cost, no damage, no pollution, etc., and has been widely used in many fields. In this paper, the vision-near-infrared spectral signals of plant leaves were obtained by means of transreflectance sampling, and the spectral data were preprocessed by smoothing, first-order differentiation and wavelet transform. Partial least square method (PLS) was used to establish the chlorophyll content and leaf absorption spectra of plant leaves.
In this paper, a new method for the determination of chlorophyll content in plants by visible near-infrared spectroscopy was proposed. The reflectance sampling method is used to collect the spectrum of the blade, and the smoothing, differential and wavelet transform methods are used to preprocess the spectral data, which reduces the influence of non-target factors and improves the signal-to-noise ratio. Then, a quantitative analysis model of leaf chlorophyll content and leaf absorption spectrum was established by using partial least square method. The prediction accuracy of the model met the requirements of practical measurement applications. The results of this study showed that the application of vision-near-infrared spectroscopy to detect the chlorophyll content of leaves was feasible, which provided a basis for the rapid detection of the chlorophyll content of leaves, and also laid a foundation for the development of corresponding non-destructive testing instruments in the future.