Spectral Band

A spectral band is a defined interval of wavelengths that a remote sensingRemote SensingRemote sensing is the science of collecting data about Earth's surface without direct physical contact, primarily usi... instrument measures during image acquisition. Sensors capture reflected or emitted electromagnetic energy across multiple bands, each tuned to a particular portion of the spectrum such as blue, green, red, near-infrared (NIR), or shortwave infrared (SWIR). The number, width, and placement of bands determine what information can be extracted from the imagery. Band characteristicsBand center wavelength defines the middle of the measured range, while bandwidth describes its width. Narrow bands provide greater spectral specificity but collect less energy, requiring a trade-off between spectral detail and signal strength. Multispectral sensors use 4-12 relatively broad bands, while hyperspectral instruments capture hundreds of narrow contiguous bands. Common bands and their usesBlue (450-520 nm) is used for coastal and bathymetric mapping. Red (630-690 nm) highlights vegetation absorption and urban features. NIR (760-900 nm) is key for vegetation health indices like NDVINDVIThe Normalized Difference Vegetation Index (NDVI) is a widely used spectral index that quantifies vegetation health a.... SWIR (1550-1750 nm) detects moisture content and distinguishes minerals. Thermal infrared bands measure surface temperature. Spectral bands are the building blocks of remote sensing analysis. The careful selection and combination of bands enables diverse applications from agriculture and forestry to geology and urban planningUrban PlanningUrban Planning is the systematic process of designing and managing the development of cities and communities. It inte..., making band design one of the most consequential decisions in sensor engineering.