Research On Polarization Spectral Characteristics Of Crops Irradiated By Multi-wavelength Laser

Since the rapid development of non-destructive testing technology,research on non-destructive testing methods for rice and other crops has become one of the hot topics in the research field.There are many types of interdisciplinary methods,and most focused on remote sensing detection.Information on early characteristics of crops such as rice,pests and diseases is difficult.Therefore,this paper proposes a method based on polarization spectrum imaging and Raman spectroscopy combined with identification and detection of rice pests and diseases.,which is derived from the principle and mathematical model of polarization bidirectional reflection distribution function(p BRDF).According to the Stokes vector analysis method,the polarization spectrum imaging system was used to obtain polarization spectrum images of rice leaves irradiated with 532 nm,590nm and 658 nm central wavelength semiconductor lasers.Comparing and analyzing the characteristic polarization spectrum images of rice obtained from three common pests and diseases(paddy rice blast,paddy rice bakanae,and paddy rice infested by(Chilo suppressalis(Walker))with healthy leaves.First,characterize the disease details under four polarization phase combination.Establish a link between polarization information and disease characteristics.Secondly,by extracting the relative polarization reflectivity in the polarization characteristic image,the polarization spectrum information of disease characteristics and healthy parts are distinguished from this dimension,and the polarization spectral characteristics of rice leaves are analyzed.In addition,in order to indirectly prove the essence of the external characteristics of the polarized spectrum image of pests and diseases,Raman spectroscopy technology is introduced to compare and analyze the Raman characteristic peaks from the internal point of view of the target and identify the main frequency shift and assignment.The molecular rotation information and internal groups were studied characteristics of change.Studies have shown that using the polarization spectrum identification system can achieve the "one disease,one strategy" physical parameter combination mode,The results of Raman spectroscopy analysis proved that the polarization spectrum identification system has the ability to accurately characterize the characteristics of rice crop pests.This paper not only provides a new method for detection and identification of precision agriculture,but also lays the foundation for the development of portable and low-cost monitoring systems.