Abstract:

The anthracnose disease index (DI) of Chinese fir and the corresponding hyper-spectral remote sensing data of the disease different severity were collected through the field investigation. The correlation between DI and the first derivative data of the canopy spectral was analyzed. Inversion models were built by selecting correlation coefficients higher than 0.7, and their precision was tested. The result showed that there was high correlation between DI and the first derivative data in the regions of 431-485 nm, 549-616 nm and 700-754 nm; and the linear model contained SDy, SDr, SDg/SDb, (SDg-SDb)/(SDg+SDb) and (SDr-SDy)/(SDr+SDy) was the best one, with the RMS (Croot mean square) error ranged from 0.094 to 0.119. This study showed hyper-spectral derivative data could estimate the disease severity of Chinese fir with a high the precision. This study has a high practical application value.

Key words: hyperspectra, differential index, Chinese Fir anthracnose, disease index, inversion models