For broad geographical coverage and satellite-based HSI, these federal and international portals are the primary sources for raw and processed data.
Hyperspectral imaging (HSI) captures hundreds of narrow, contiguous wavelength bands, typically spanning the visible, near-infrared (NIR), and shortwave infrared (SWIR) spectrums. This "imaging spectroscopy" provides a detailed chemical fingerprint for every pixel, making it essential for applications in agriculture, mineralogy, and environmental monitoring.
If you are looking to for research or machine learning, several high-quality, open-access repositories and benchmark scenes are available. 1. Major Open-Access Portals