Retrieval of typical subtropical crop canopy SPAD value in South China using GF-1 remote sensing image

Objective The purpose of this paper was to explore the retrieval of typical subtropical crop SPAD value in South China with the domestic high resolution satellite image, using Zengcheng Teaching and Research Station for field experiments.

Method According to the GF-1 remote sensing data and corresponding subtropical crops measured data on October 1, 2013, the models between vegetation index and typical crop canopy SPAD value were built.In order to get the best regression model for retrieval of subtropical crop canopy related to contents of chlorophyll in South China, the linear and nonlinear relations were found between the nine types of vegetation indices and crop canopy SPAD value.

Result and conclusion The results showed that seven types of vegetation indices had an extremely significant correla-tion with typical subtropical crop canopy SPAD value, and the ratio vegetation index exponential regression model (Y = 31.445e^0.141X) provided the best model for retrieving subtropical crop canopy SPAD value (R² = 0.889, and fitting precision = 92.75%), which indicates ratio vegetation index is feasible to retrieve large range of typical subtropical crop canopy SPAD value in the study area.