[Impact of dust-fall on spectral features of plant leaves].

In order to build inversion model of dust-fall weight by hyperspectral data, 30 samples were collected in Beijing. Through electronic balance and Analytical Spectral Devices FieldSpec Pro (ASD) analysis, the "dust leaves" and the "clean leaves" weight and spectral reflectance were determined respectively, which also obtained information of dust weight and spectral features. Then, based on tradition and partial least squares (PLS) model's analysis, the relationship between dust weight and spectral reflectance was explored. The results showed that 350-700, 780-1 300 and 1 900-2 500 nm bands had apparently variations when they response to the different dust weights. In general, there was a negative relationship between dust weight and spectral reflectance, the maximum negative value -0.8 occurred at 737 band which belonged to near-infrared bands. In the analysis of dust weight with multi-band, it was indicated that NDVI index which was formed by 948 and 945 bands had a significant correlation (r = 0.76) to dust. Finally, through accuracy assessment of regression model, the PLS could obtain a more accurate result than the traditional model.