Earth Observation (EO) is the collection of information about Earth’s physical, chemical, and biological systems from satellite or airborne platforms. Three dominant sensing modalities define the field:
Synthetic Aperture Radar (SAR) — active microwave (typically 1–10 GHz) illumination that creates high-resolution imagery independent of cloud cover or illumination. Penetrates vegetation; used for ship-detection, subsidence monitoring, ice mapping. See SAR Satellites (Synthetic Aperture Radar).
Optical / multispectral — passive solar-reflectance imaging in the visible and near-infrared. Ground sampling distance (GSD) is the key resolution parameter; commercial leaders are now sub-30 cm (Planet, Maxar). See Optical EO (Planet, Maxar).
Hyperspectral — measures hundreds of contiguous spectral bands (typically 400–2,500 nm), enabling material identification and greenhouse-gas (GHG) attribution that broad multispectral cannot resolve. See Hyperspectral Satellites.
The commercial EO market has been reshaped by launch cost reduction: a 100 kg LEO satellite that cost $50M to launch in 2010 costs under $3M today (Falcon 9 rideshare). This enabled small-sat constellations with daily-revisit cadences, converting EO from a government capability into a commercial data product. Atmospheric composition sensing (Atmospheric Sensing) extends the modality set to methane, CO2, and aerosol monitoring.
Investment relevance: Commoditisation of raw imagery is near-complete; value has migrated to analytics, change-detection pipelines, and foundation models trained on EO data. Fundable wedges are payload technology (novel spectral range or resolution) or data-derived intelligence for specific verticals (agriculture, insurance, critical infrastructure).
Frontier
- Can commercial hyperspectral constellations achieve daily revisit at sub-10 m resolution for systematic GHG attribution?
- Which EO data layers command durable pricing power as raw resolution commoditises?
- How much of EO analytical value migrates to on-board inference vs ground processing?