Multi-angle Quantitative Detection Model Of Jujube In Southern Xinjiang Based On Optical Fiber Spectroscopy

Optical fiber spectroscopy technology can obtain the spectral information of tested samples quickly,accurately and without contact,while Angle factors have a great influence on the non-contact measurement.In order to quantitatively describe the difference of reflectance at different angles caused by the zenith Angle of light source(?_i),detection zenith Angle(?_r)and relative azimuth Angle(?),which affected the quality detection accuracy of winter jujube in South Xinjiang.Carried out indoor,therefore,different light source zenith Angle and different relative azimuth detection test,the analysis of features of affect winter jujube in South Xinjiang quality detection Angle,exploring different source zenith Angle and different relative azimuth Angle of winter jujube in South Xinjiang spectra inversion method and steps of south xinjiang multi-angle quality quantitative detection research of model validation,the main research conclusions are as follows:(1)Winter jujube in southern Xinjiang was taken as the research object.The zenith Angle of light source was 69.2°,63.62°,59.32°,55.79°,52.78°,detection zenith Angle was 33.5°,relative azimuth Angle was180°,and the zenith Angle of light source was 69.45°,detection zenith Angle was 33.5°.The relative azimuth angles were 120°,130°,140°,160°,170°and 180°,and the collected spectra were preprocessed to establish the PLS water model and PLS-SSCmodel of winter jujube in South Xinjiang,and the model accuracy was compared.The correlation coefficients R of water content model were 0.942,0.953,0.941,0.999 and 0.658,respectively.The SSC content models were 0.718,0.960,0.996,0.991 and 0.883,respectively.The correlation coefficients R of water content model were 0.984,0.661,0.643,0.919,0.938,0.925,respectively.The SSC content model was 0.941,0.888,0.412,0.977,0.837,0.318,respectively.The results showed that when the zenith Angle of light source was 55.79°,the detection zenith Angle was 33.5°,and the relative azimuth Angle was 120°,the best water content model was established for winter jujube in South Xinjiang.When the zenith Angle of light source was 59.32°,the detection zenith Angle was 33.5°,and the relative azimuth Angle was 160°,the SSC model of winter jujube in South Xinjiang PLS was the best,which had the greatest influence on the SSC detection accuracy of jujube.(2)Rojean model and Ross-Li model were used to invert the spectra of winter jujube in South Xinjiang at different relative azimuth angles and zenith angles of different light sources.When the zenith Angle of the light source was 69.45°,the detection zenith Angle was 33.5°,and the relative azimuth Angle increases successively,the accuracy of the inversion of the spectrum of winter jujube in South Xinjiang was the highest at 160°.When the relative azimuth Angle was 180°,the detection zenith Angle ws 33.5°,and the light source zenith Angle increases successively,the Rojean model has the highest accuracy when the light source zenith Angle was 59.32°.The Ross-Li model was used to obtain the highest spectral accuracy at the zenith Angle of 52.78°.The two models have the best fitting effect in the wavelength range of 550?620 nm and 700?950 nm.The fitting effect is poor in the wavelength range of 450?540 nm and 640?690 nm,which may be due to interference caused by absorption peaks at 640?690 nm.Therefore,Rojean model is more suitable than Ross-Li model to invert the spectra of different relative azimuth angles and zenith angles of different light sources.(3)The experimental measurement,Rojean model inversion,Ross-Li model inversion in the light source zenith Angle was 69.45°,detection zenith Angle was 33.5°,under different relative azimuth angles of the winter jujube in South Xinjiang spectrum and the winter jujube in South Xinjiang moisture and SSC established by the PLS water model and SSC model comparative analysis.The study found that,Rojean model and Ross-Li model were used to invert the best moisture model and SSC model of winter jujube in South Xinjiang under the conditions of 69.45°zenith Angle of light source,33.5°zenith Angle of detection and 120°relative azimuth Angle,and their correlation coefficients were 0.998 and 0.997.The test measured,Rojean model inversion,Ross-Li model inversion in the detection zenith Angle was 33.5°,the relative azimuth Angle was 180°,different light source zenith Angle of southern Xinjiang winter jujube spectrum in the water and SSC content of winter jujube in South Xinjiang established PLS water model and SSC model comparative analysis,the study found that,Using ross-Li model and Rojean model,the water content model and SSC content model of winter jujube in South Xinjiang were the best under the conditions of light source zenith Angle of 63.62°,detection zenith Angle of 33.5°and relative azimuth Angle of 180°,and their correlation coefficients were 0.999 and 0.998.The test results showed that when the zenith Angle of light source was 63.62°,the detection zenith Angle was 33.5°,and the relative azimuth Angle was 120°,the quality model of winter jujube in South Xinjiang was better predicted by using the spectral inversion of Rojean model and Ross-Li model,which could effectively reduce the error caused by Angle factors in quality detection of winter jujube in South Xinjiang.To improve the quality testing accuracy of winter jujube in South Xinjiang,and to provide reference for improving the nondestructive testing accuracy of outdoor winter jujube in South Xinjiang.