Journal of Applied Sciences ›› 2022, Vol. 40 ›› Issue (6): 941-952.doi: 10.3969/j.issn.0255-8297.2022.06.005

• Signal and Information Processing • Previous Articles    

Hyperspectral Inversion of Soil Heavy Metal Mass Concentration Based on Semi-supervised Regression

MAO Gengxuan1,2, TU Yan3, CUI Wenbo1,2, TAO Chao1,2   

  1. 1. School of Geoscience and Info-physics, Center South University, Changsha 410083, Hunan, China;
    2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, Center South University, Changsha 410083, Hunan, China;
    3. Hunan Institute of Science and Technology Information, Changsha 410001, Hunan, China
  • Received:2022-03-16 Published:2022-12-03

Abstract: Aiming at training a robust inversion model of soil heavy metal mass concentration with a small number of labeled samples and a large number of unlabeled samples, we took cadmium (Cd) in soil as research object, and experimentally verified the model by using two groups of the spectral data of four different regions (Hengyang-Chenzhou, Yuanping-Baoding). A hyperspectral retrieval model of soil heavy metal mass concentration based on semi-supervised regression was proposed after reducing the spectral distribution differences of different regions by means of transfer component analysis. Experimental results show that compared with traditional fully supervised modeling method, in the group of Hengyang-Chenzhou, the semi-supervised method proposed in this paper can improve the determination coefficient R2 to 0.75 and relative percent difference (RPD) to 2.15; In the group of Yuanping-Baoding, R2 increases to 0.70, and RPD increases to 1.61. The experiments show that the model inversion accuracy can be effectively improved by introducing a large number of unlabeled samples to semi-supervised regression analysis in the situations of few labeled samples.

Key words: hyperspectral remote sensing, semi-supervised regression, transfer component analysis, inversion of soil heavy metal mass concentration

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