Spectral Signature Curves

Spectral signature curves indicate the variation in reflectance or emittance of materials as a function of wavelength in the electromagnetic spectrum, enabling their identification based on unique spectral responses. Different surfaces interact with radiation through absorption, reflection and transmission, producing distinct signatures. Among major Earth surface features, vegetation, water and soil exhibit distinct patterns. Vegetation shows low reflectance in the visible and high in the near-infrared region, water exhibits consistently low reflectance in the near-infrared and soils display gradual increases in reflectance as influenced by moisture and composition. These spectral characteristics form the basis of remote sensing applications such as land cover mapping, crop assessment and water and soil analysis.