Physics / mechanism
Hyperspectral satellites capture reflected or emitted electromagnetic radiation across hundreds of contiguous narrow spectral bands (typically 5–10 nm bandwidth) spanning VNIR through SWIR or LWIR (400–2500 nm+). Each ground pixel carries a full spectral signature, enabling material identification rather than just colour differentiation. Pushbroom sensors dominate: a line of detector pixels dispersed through a prism or grating onto a 2D focal-plane array (FPA). Key parameters: spectral resolution, SNR (target >200:1), GSD (commercial leaders now at 3–10 m), and revisit rate. State of the art: Planet’s Tanager (30 bands, SWIR, methane detection), HyperScout, and Pixxel’s Firefly constellation (55 bands, 5 m GSD). Onboard processing increasingly necessary to manage downlink bandwidth.
Competitive landscape
Multispectral imaging (Sentinel-2, Landsat: 10–13 broad bands) handles most commodity use cases at lower cost and higher cadence. Thermal IR imagers (LWIR) compete for emissions monitoring. SAR offers all-weather, day-night operation but no chemical specificity. Airborne hyperspectral (AVIRIS-NG, HySpex) gives higher SNR and flexibility but no persistent coverage. On the detector side, InGaAs FPAs (SWIR) and HgCdTe (LWIR) are the incumbent materials; emerging CMOS-integrated filter arrays threaten cost structure.
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.