Physics / mechanism
Optical Earth Observation (EO) satellites capture reflected solar radiation across visible, near-infrared, and shortwave-infrared bands using push-broom or frame-camera architectures. Planet’s SuperDove constellation (~200 satellites) delivers 3–5 m GSD multispectral imagery at daily revisit; Maxar’s WorldView Legion targets 30 cm GSD panchromatic. Key parameters: ground sample distance (GSD), signal-to-noise ratio, swath width, revisit cadence, and radiometric calibration. Optical EO is daylight/cloud-limited. Focal-plane arrays use silicon CMOS or InGaAs for SWIR; detector pitch and telescope aperture set the resolution ceiling. State of the art pushes sub-30 cm commercial GSD with onboard radiometric correction and compressed downlink.
Competitive landscape
SAR (Capella, ICEYE, Umbra) competes directly—cloud-penetrating, day/night, coherent phase data but lower intuitive interpretability and higher per-image cost. Hyperspectral (Pixxel, HyperScout) adds spectral resolution (200+ bands) at cost of GSD and data volume. Thermal IR (Satellogic, Orbital Sidekick) addresses different phenomenology. Multispectral vs. hyperspectral vs. SAR is a sensor-fusion problem, not winner-takes-all.
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.