基于联合算法的高光谱土壤有机质含量估测

Estimation of hyperspectral soil organic matter content based on joint algorithm

  • 摘要:
    针对高光谱土壤有机质数据冗余信息较多以及单一特征波段选择算法存在结果不确定性问题,本文提出联合多种单一算法筛选特征波段建立模型。首先采集贵州省13个县市区的189个土壤样本,并将其光谱数据作为数据源,其次将CARS(Competitive adaptive Reweighted Sampling)、UVE(Uninformative Variable Elimination)、SPA(Simultaneous Perturbation Algorithms)和IRIV(Iteratively Retained Informative Variables)特征波段筛选算法进行联合,在多种联合算法中优选出3种优化联合算法,最后基于支持向量机和随机森林构建土壤有机质含量反演模型。结果表明:在土壤有机质反演模型中,UVE-SPA-SVM模型的决定系数达到0.87(R2=0.87),均方根误差达到8.31(RMSE=8.31),相对分析误差为2.72(RPD=2.72),在3种优化联合算法中表现最好,表现优
    于四种单一筛选算法(CARS、UVE、SPA、IRIV)。表明优化联合算法在高光谱数据降维和提升模型精度方面相比单一算法具有明显优越性,且UVE-SPA-SVM能较好适用于研究区土壤的有机质含量估测。通过对比不同模型的精度,本研究旨在验证优化后的联合算法在特征波段筛选中相较于单一算法的优越性,从而为山区耕地土壤有机质含量的高精度反演提供更为可靠和高效的算法支持。

     

    Abstract: In view of the large redundancy information of hyperspectral soil organic matter data and the uncertainty of the results of the single feature band selection algorithm, this paper proposes to establish a model by combining multiple single algorithms to screen the feature bands. Firstly, 189 soil samples from 13 counties and urban areas of Guizhou Province are collected, and their spectral data are used as data source. Secondly, four feature band screening algorithms, i.e. kings of CARS (Competitive adaptive Reweighted Sampling), UVE (Uninformative Variable Elimination), SPA (Simultaneous Perturbation Algorithms) and IRIV (Iteratively Retained Informative Variables) feature band screening algorithms are combined, and three optimization joint algorithms are selected among the multiple joint algorithms. Finally, soil organic matter content inversion model is constructed based on support vector machine and random forest. The results show that in the soil organic matter inversion model, the determination coefficient of UVE-SPA-SVM model reaches 0.87(R2=0.87), the root mean square error reaches 8.31(RMSE=8.31), and the relative analysis error is 2.72(RPD=2.72), which showes the best performance among the three optimization joint algorithms. The performance is better than four single screening algorithms (CARS, UVE, SPA, IRIV). It shows that the optimized joint algorithm has obvious advantages over the single algorithm in reducing hyperspectral data and improving model accuracy. By comparing the accuracy of different models, this study aims to verify the superiority of the optimized combined algorithm compared with a single algorithm in the feature band screening, so as to provide a more reliable and efficient algorithm support for the high-precision inversion of soil organic matter content in mountainous cultivated land.

     

/

返回文章
返回