Research on SPAD Estimation Model for Spring Wheat Booting Stage Based on Hyperspectral Analysis

With the rapid progression of agricultural informatization technology, the methodologies of crop monitoring based on spectral technology are constantly upgraded. In order to carry out the efficient, precise and nondestructive detection of relative chlorophyll (SPAD) during the booting stage, we acqu...

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Main Authors: Hongwei Cui, Haolei Zhang, Hao Ma, Jiangtao Ji
Format: Article
Language:English
Published: MDPI AG 2024-03-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/24/5/1693
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author Hongwei Cui
Haolei Zhang
Hao Ma
Jiangtao Ji
author_facet Hongwei Cui
Haolei Zhang
Hao Ma
Jiangtao Ji
author_sort Hongwei Cui
collection DOAJ
description With the rapid progression of agricultural informatization technology, the methodologies of crop monitoring based on spectral technology are constantly upgraded. In order to carry out the efficient, precise and nondestructive detection of relative chlorophyll (SPAD) during the booting stage, we acquired hyperspectral reflectance data about spring wheat vertical distribution and adopted the fractional-order differential to transform the raw spectral data. After that, based on correlation analysis, fractional differential spectra and fractional differential spectral indices with strong correlation with SPAD were screened and fused. Then, the least-squares support vector machine (LSSSVM) and the least-squares support vector machine (SMA-LSSSVM) optimized on the slime mold algorithm were applied to construct the estimation models of SPAD, and the model accuracy was assessed to screen the optimal estimation models. The results showed that the 0.4 order fractional-order differential spectra had the highest correlation with SPAD, which was 9.3% higher than the maximum correlation coefficient of the original spectra; the constructed two-band differential spectral indices were more sensitive to SPAD than the single differential spectra, in which the correlation reached the highest level of 0.724. The SMA-LSSSVM model constructed based on the two-band fractional-order differential spectral indices was better than the single differential spectra and the integration of both, which realized the assessment of wheat SPAD.
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spelling doaj.art-7c1d20fe1fce4fd78623d55397be7b6d2024-03-12T16:55:39ZengMDPI AGSensors1424-82202024-03-01245169310.3390/s24051693Research on SPAD Estimation Model for Spring Wheat Booting Stage Based on Hyperspectral AnalysisHongwei Cui0Haolei Zhang1Hao Ma2Jiangtao Ji3College of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang 471000, ChinaCollege of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang 471000, ChinaCollege of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang 471000, ChinaCollege of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang 471000, ChinaWith the rapid progression of agricultural informatization technology, the methodologies of crop monitoring based on spectral technology are constantly upgraded. In order to carry out the efficient, precise and nondestructive detection of relative chlorophyll (SPAD) during the booting stage, we acquired hyperspectral reflectance data about spring wheat vertical distribution and adopted the fractional-order differential to transform the raw spectral data. After that, based on correlation analysis, fractional differential spectra and fractional differential spectral indices with strong correlation with SPAD were screened and fused. Then, the least-squares support vector machine (LSSSVM) and the least-squares support vector machine (SMA-LSSSVM) optimized on the slime mold algorithm were applied to construct the estimation models of SPAD, and the model accuracy was assessed to screen the optimal estimation models. The results showed that the 0.4 order fractional-order differential spectra had the highest correlation with SPAD, which was 9.3% higher than the maximum correlation coefficient of the original spectra; the constructed two-band differential spectral indices were more sensitive to SPAD than the single differential spectra, in which the correlation reached the highest level of 0.724. The SMA-LSSSVM model constructed based on the two-band fractional-order differential spectral indices was better than the single differential spectra and the integration of both, which realized the assessment of wheat SPAD.https://www.mdpi.com/1424-8220/24/5/1693spring wheatbooting stageSPADfractional-order differentiationSMA-LSSSVMfractional-order differentiation spectral index
spellingShingle Hongwei Cui
Haolei Zhang
Hao Ma
Jiangtao Ji
Research on SPAD Estimation Model for Spring Wheat Booting Stage Based on Hyperspectral Analysis
Sensors
spring wheat
booting stage
SPAD
fractional-order differentiation
SMA-LSSSVM
fractional-order differentiation spectral index
title Research on SPAD Estimation Model for Spring Wheat Booting Stage Based on Hyperspectral Analysis
title_full Research on SPAD Estimation Model for Spring Wheat Booting Stage Based on Hyperspectral Analysis
title_fullStr Research on SPAD Estimation Model for Spring Wheat Booting Stage Based on Hyperspectral Analysis
title_full_unstemmed Research on SPAD Estimation Model for Spring Wheat Booting Stage Based on Hyperspectral Analysis
title_short Research on SPAD Estimation Model for Spring Wheat Booting Stage Based on Hyperspectral Analysis
title_sort research on spad estimation model for spring wheat booting stage based on hyperspectral analysis
topic spring wheat
booting stage
SPAD
fractional-order differentiation
SMA-LSSSVM
fractional-order differentiation spectral index
url https://www.mdpi.com/1424-8220/24/5/1693
work_keys_str_mv AT hongweicui researchonspadestimationmodelforspringwheatbootingstagebasedonhyperspectralanalysis
AT haoleizhang researchonspadestimationmodelforspringwheatbootingstagebasedonhyperspectralanalysis
AT haoma researchonspadestimationmodelforspringwheatbootingstagebasedonhyperspectralanalysis
AT jiangtaoji researchonspadestimationmodelforspringwheatbootingstagebasedonhyperspectralanalysis