The parameters design of signal processing circuit for crop canopy spectrometer based on active light source

Based on self-developed crop canopy reflectance spectrometer, a method for measuring the reflection spectrum of crop canopy using active light source was discussed in this paper. As well as systematically introduced the measuring principle, a signal processing circuit was designed, which was applicable to detect high-frequency pulse light emitted by active light source. The effects of passive light source and signal source were given full consideration during the design process. Then, the method based on control theory was used to analyze and deduce the key parameters of the signal processing circuit. The experimental results showed that the circuit had high stability and better dynamic response performance, which could meet the needs of the crop canopy reflectance spectra detection. The impact of external ambient light on the spectrometer measuring results was almost completely filtered and the response caused by active light source was detected efficiently.