Evaluation of Narrowband and Broadband Vegetation Indices for Determining Optimal Hyperspectral Wavebands for Agricultural Crop Characterization

Abstract

he main goal of the study was to determine optimal waveband centers and widths required to best estimate agricultural crop characteristics. The hyperspectral narrowband data was ac-quired over 395 to 1020 nanometers using a 1.43-nanometer-wide, 430 bands, hand-held spectroradiometer. Broadband data were derived using a Landsat-5 Thematic Mapper image acquired to correspond with field spectroradiometer and ground-truth measurements. Spectral and biophysical data were obtained from 196 sample locations, including farms and rangelands. Six representative crops grown during the main cropping season were selected: barley, wheat, lentil, cumin, chickpea, and vetch. Biophysical variables consisted of leaf area index, wet biomass, dry biomass, plant height, plant nitrogen, and canopy cover.