Spectral signatures and identification of some summer crops using remote sensing techniques.

摘要

The spectral reflectance response characteristics of some summer crops (maize single hybrid 10 and 3-way hybrid 320; cotton cultivars Giza 88 and Giza 85; and rice cultivars Sakha 101 and Giza 178), the effect of changes in the agronomic variable on the NDVI (normalized difference vegetation index) of the crops during the different growth stages, and the potential use of NDVI data for crop identification were evaluated in a field in Kalubia Governorate, Egypt during the 2003 and 2004 seasons. Morphophysiological measurements (leaf area index, LAI; fresh biomass; and dry biomass) were acquired at approximately every 15 days throughout the growing season, on the same days when spectral measurements were taken. The other agronomic characters measured were plant height and chlorophyll content. Reflectance ranges of 0.45-0.90 micro m wavelength were obtained with a radiometer in 4 wavelength bands (0.45-0.52, 0.52-0.60, 0.63-0.69 and 0.76-0.90 micro m). High correlations were observed between NDVI, and LAI, fresh biomass and chlorophyll content. NDVI was useful in identifying crops at the maximum vegetative stage..