Hyperspectral Response of Rice Canopy and Prediction of Its Chlorophyll Content in Cold Regions

다국어 초록 (Multilingual Abstract)

Based on field trials of different nitrogen levels, rice canopy chlorophyll content and canopy spectrum of its booting stage were respectively measured using the nitrogen balance index meter and the hyperspectral imager, in the Northeast of china. Analyzing the rice canopy spectral response characteristics under nitrogen gradient after canopy reflectance spectra were first extracted and filtered for noise, then the original reflectance spectra were transformed into the first derivative reflectance for further analysis. Stepwise analysis was carried out to select sensitive bands for canopy chlorophyll content by making correlation analysis and to build spectral indexes, and then chlorophyll content prediction models were generated and tested. After comparing, the two models with better estimation precision were the model with reflectivity at 572nm as a variable and the model with the index DSI(572,682) constructed the reflectivity at 572 and 682nm as a variable, the coefficients of determination R2 were 0.733 and 0.694, the root mean square errors RMSE were 2.9656 and 3.0346, and the relative errors RE% were 7.07% and 7.43%.

목차 (Table of Contents)

• Abstract
• 1. Introduction
• 2. Materials and Methods
• 2.1 Study Area
• 2.2 Hyperspectral Measurements and Pre-processing
• 2.3 Canopy Chlorophyll Measurements
• 2.4 Data Analysis
• 3. Results and Discussion
• 3.1 Spectral Response of Rice Canopy Chlorophyll under Different Nitrogen Levels
• 3.2 Correlation Analysis
• 3.3 Modelling Canopy Chlorophyll
• 3.4 Model Validation
• 4. Conclusions
• Acknowledgements
• References