Spectral signature refers to the characteristic pattern of interaction between electromagnetic radiation and a given object or material as recorded by a remote sensing sensor. When solar radiation strikes the Earth’s surface, different materials absorb, reflect, and transmit energy in varying proportions across different wavelengths of the electromagnetic spectrum. This unique pattern of reflectance or emittance as a function of wavelength forms the spectral signature of that object. Spectral signatures are fundamental to remote sensing because they enable identification, classification, and analysis of surface features such as vegetation, soil, water bodies, and built-up areas using multispectral and hyperspectral data. In remote sensing, spectral signatures are usually represented graphically by plotting reflectance values on the vertical axis against wavelength on the horizontal axis. Such curves help in understanding how a particular feature behaves in the visible, near-infrared, and shortwave infrared regions of the spectrum. Since no two materials interact with electromagnetic radiation in exactly the same way, spectral signatures act as diagnostic fingerprints, allowing analysts to distinguish one feature from another even if they appear similar to the human eye. Vegetation exhibits one of the most distinctive and widely studied spectral signatures in remote sensing due to its strong relationship with plant physiology and health. In the visible region of the spectrum, particularly in the blue (0.45–0.52 µm) and red (0.63–0.69 µm) wavelengths, vegetation shows relatively low reflectance. This is primarily because chlorophyll pigments present in green plants absorb strongly in these regions for photosynthesis. Absorption in the blue region supports vegetative growth, while absorption in the red region is crucial for energy conversion during photosynthesis. As a result, healthy