Spectral signature studies in optical region

Abstract

Reflectance spectra of a large number of rock, vegetation and soil samples have been measured in the laboratory in the visible and near infrared wavelength regions. Procedures have been evolved to find optimum spectral bands for rock discrimination. 'In situ' reflectance measurements on different crops like wheat, paddy, millet, cotton, maize, groundnut etc. during their various growth stages have been carried out using hand-held radiometers. Recently measurements have been conducted over six wheat plots subjected to different irrigation schedules to see the effect of water stress on the signatures. Results show that the best period for monitoring water stress in wheat through remote sensing is 45-80 days after sowing.