基于近红外高光谱成像技术南疆冬枣DOLP五次多项式拟合模型研究

Study on Dolp Five-dimensional Polynomial Fitting Model for Jujube Based on Near Infrared Hyperspectral Imaging Technology

利用高光谱相机采集冬枣图谱信息对其进行Dolp(Degree of Linear Polarizationg)处理,通过对数分析发现DOLP与相位角密切相关,本试验在探测器方位角分别为0°、30°、45°扫描时,实验架最左侧一排红枣的相位角分别为:45.7°、66.5°、72.58°,实验架最右边一排红枣的相位角分别为:73.44°、90.36°、94.77°,白板左侧一排红枣的相位角分别为:52.2°、75.48°、88.33°,白板右侧一排红枣的相位角分别为:65.38°、87.86°、90.64°。从12个相位角的南疆冬枣数据中任选9个,但三次扫描所对应的相位角中各留一个用来预测,后利用Matlab对Dolp进行五次多项式拟合。由于长波部分时Dolp值较高,数值变化更明显,所以从全波段中选三个长波1300 nm、1400 nm、1500 nm进行分段预测,由拟合试验结果可知,相位角为52.2°、75.48°、88.33°时,南疆冬枣Dolp分量的误差分别为:6.38%、2.61%、2.81%。进而可以反演2π空间内的南疆冬枣任意入射角和探测角的Dolp值,本文为今后解决相位角对南疆近地面红枣品质遥感检测奠定了基础。

Using hyperspectral cameras capture winter jujube map information on the DOLP(DegreeofLinearPolarizationg)treatment in logarithmic analysis DOLP is closely related to the phase Angle,the experiment in the detector azimuth respectively 0°,30°,45°scan,the experiment on the left of a row of red jujube phase Angle are 45.7°,66.5°,72.58°,the phase angles of the row of dates on the far right of the experimental rack are 73.44°,90.36°,94.77°,the phase angles of the row of dates on the left of the whiteboard are 52.2°,75.48°,88.33°,and the phase angles of the row of dates on the right of the whiteboard are:65.38°,87.86°,90.64°.Nine of the 12 phase angles of winter jujube data in southern Xinjiang were selected,but one of the phase angles corresponding to the three scans was reserved for prediction.Finally,quintic polynomial fitting was carried out on DOLP by using MATLAB.Due to the high value of DOLP in the long wave part,the numerical variation is more obvious,so three long waves of 1300nm,1400nm and 1500nm are selected from the whole wave band to perform segmentation prediction.According to the fitting experimental results,when the phase Angle is 52.2°,75.48°and 88.33°,the errors of DOLP component of Southern Xinjiang winter jujube are as follows:6.38%,2.61%,2.81%.The DOLP values of the arbitrary incidence Angle and detection Angle in 2πspace can be retrieved,which lays a foundation for the solution of the phase Angle remote sensing detection of the quality of the near-surface red jujube in southern Xinjiang in the future.