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AVIRIS data from Blythe were acquired in June 1997 to study the agricultural spectra from different crops and for identification of crops in other areas with similar environmental factors and similar spectral properties. The main objectives of this study are: 1) to compare the spectral and radiometric characteristics of AVIRIS data from verities of cotton crop with the spectra measured by FieldSpecR ASD radiometer; 2) to explore the use of AVIRIS images in identifying agricultural crops; 3) to study the impact of environmental factors on selected crops and; 4) to build a spectral library for the cotton crop varieties that were studied. A long-term goal is to extend the spectral library for different vegetation or crops in different stages of growth or different varieties. In order to support our study, on June 26, 2001 we collected spectral data using the FieldSpec spectrometer from selected fields planted with different cotton varieties at Blythe area, California (at the Longitude 114° 41.88 W and Latitude 33° 24.27N to Longitude 114° 41.86 W and Latitude 33° 24.00N). The spectral data of cotton varieties were studied. Environmental parameters were studied such as the soil water content (WC), pH, organic matter (OM), C% and nitrogen (N%). The results of this study showed that there were differences in the signatures of different cotton varieties. Also, there was a significant correlation between the data that were collected by AVIRIS image scene in 1997 and spectral data collected by the FieldSpec spectrometer. This correlation allowed us to build a spectral library to be used in ENVI-IDL software. This leads to identification of different cotton varieties and in particular the visible part of the spectra. AVIRIS data are in agreement with FieldSpec data. Using IDL algorithms of Spectral Angle Mapper classification (SAM), Spectral Feature Fitting (SFF) and Spectral Binary Encoding (SPE) showed that there is an excellent agreement between the predicted and the actual crop type (i.e. the correlation is between 85 - 90% match). Further use of the AVIRIS images can be of a value to crops identification or crops yield for commercial use. The yield data of Cotton varieties were correlated significantly with the spectral data from the AVIRIS and from the hand-held radiometer and it showed the impact of different environmental parameters on the yield of the crop.
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