SENet-SVWF: a spectral vegetation indices and wavelet features fusion method using squeeze and excitation network for predicting the SPAD value of maize leaves.

Abstract

Hyperspectral technology is used to monitor the SPAD (Soil and Plant Analysis Development) of maize, which is of great significance for regulating maize growth, optimizing nutrient management and improving yield formation. However, too much spectral information of hyperspectral data has resulted in the parameters redundancy and the complex structure of model. To solve this problem, a spectral vegetation indices (VIs) and wavelet features (WF) fusion method using squeeze-and-excitation network (SENet-SVWF) was proposed in this study. The partial least squares regression (PLSR), support vector regression (SVR), random forest regression (RFR), extreme gradient boosting (XGBoost) and long short-term memory (LSTM) predictors and five pretreatment methods were used in predicting SPAD value of maize, and the best pretreatment method and predictor were determined. VIs and wavelet transform (WT) were used to analyze the spectral data after the best pretreatment. Pearson correlation analysis and peak extraction method were used to determine the combination of VIs and WF. The SENet was introduced to fuse the selected VIs and WF, and the corresponding weights of different spectral features were optimized. The results showed that the multivariate scattering correction (MSC) was identified as the best pretreatment method, and SVR and RFR predictors performed best. The model established using SE-VIs-WF spectral features combined with RFR has the highest accuracy. The R 2 of the test set at V6, V8, V12 and R1 were 0.570, 0.760, 0.824 and 0.742, the root mean squared error (RMSE) were 1.199, 1.786, 1.994 and 3.118, respectively. Compared with the spectral data after MSC pretreatment, the R 2 of the model test set increased by 6.742%, 13.264%, 20.644% and 8.480%, and the number of model input features decreased by 541, 539, 539 and 541. The method proposed would achieve accurate prediction of SPAD value of maize and provide new ideas for crop nutrition information estimation.

Plant phenotyping relevance

トウモロコシ葉のSPAD値という植物生理形質を、ハイパースペクトル特徴量と深層学習で推定する手法を開発・評価しており、表現型取得・抽出が中心である。

Code and data availability

植物フェノタイピング解析を再現する公開資産であることを、入力本文と直接リンクから確認できなかったため保留しました。

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